- Iran, Islamic Republic of
- 00982161118871
Mehdi Shahbazi
University of Tehran, Motor Behavior and Sport Psychology, Faculty Member
- University of Tehran, Motor Control and Learning Department, Faculty Memberadd
- Human Motor Behavior, Neuropsychology, Sport Psychology, Experimental Psychology, Embodied Cognition, Motor Control, and 20 moreAutism Spectrum Disorders, Fractals, Attention-Deficit/Hyperactivity Disorder, Neuropsychiatry, Motor Simulation, Attention, Handedness, Coordination Dynamics, Fitts's Law, Psychology, Cognitive Science, Cognitive Psychology, Neuroscience, Education, Philosophy, Sociology, Anthropology, Social Psychology, Social Sciences, and Historyedit
- phdedit
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مجموعه مقالات اولین همایش ملی انجمن علمی رفتار حرکتی و روانشناسی ورزشی ایران (100 جلد)
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اکتساب مهارت در ورزش: تحقیق، نظریه و کاربرد
Research Interests: Teaching Skills and Sport
ادراک وتصمیم گیری در ورزش
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کنترل حرکتی و یادگیی حرکتی
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تاریخ تربیت بدنی و ورزش: سیری در بازی های آسیایی 1913 تا 2014
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The purpose of this study was to examine the effect of motor dependent/independent visual perception training on visual-motor integration and fine motor skills of 7-8 year old children. For this purpose, 107,1stgrade primary school... more
The purpose of this study was to examine the effect of motor dependent/independent visual perception training on visual-motor integration and fine motor skills of 7-8 year old children. For this purpose, 107,1stgrade primary school students in Sabzevar were selected through purposive sampling (equal economical and cultural status, optimum health and full sight with or without wearing glasses) and randomly divided into two experimental (no=32)and a control group (no=43). After pre-test, the experimental groups was trained in movement dependent and independent visual-perception tasks. Both groups performed their tasks for three sessions, 45-minute per weeks and for six consecutive weeks. Shapiro-Wilk and Levin test results confirmed the normality and homogenity of data and ANCOVA showed that both training programs significantly improved visual-motor integration and fine motor skills of 7 to 8 years old children. Bonferronitest indicated that there were no significant differences between the movement dependent and independent training programs. The data analysis was performed by using SPSS 19.0. The results of this study confirmed the purposed "movement" hypothesis stating that the significant contributor to the development of perception and perceptual-motor components is not the active movements of the individual, but rather it is the attention of the person to the visual stimuli within the environment.
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Abstract Introduction and Purpose: The purpose of this study was to compare the effect of self-regulation feedback with Bandwidth feedback through self-modeling strategies on volleyball service in novice and intermediate learners.... more
Abstract Introduction and Purpose: The purpose of this study was to compare the effect of self-regulation feedback with Bandwidth feedback through self-modeling strategies on volleyball service in novice and intermediate learners. Methodology:For this purpose, 22 novice and 24 intermediate learners took part in this experiment. Each group practiced volleyball tennis skills in six sessions in two sub-groups of self-regulation and Bandwidth feedback methods through self-modeling strategies. The design involved a pretest, acquisition sessions post-test, retention test in two condition (Easy and difficult) and a transfer test. In each session, the self-regulation feedback sub-group was matched to the number of feedbacks received by Bandwidth feedback subgroup; but the self-regulation feedback subgroup has a self-controlled role in when they receive feedback. Results and Conclusions: The results of repeated measure showed that both methods of providing feedback in both groups improved the performance level of the subjects in the post-test, retention test and transfer test significantly(p<0.05). AlsoThe results of the t test showed that the beginners benefited from self-regulation feedback more than Bandwidth feedback in the, Difficult retention test and transfer test and they had superior motor skill learning(p<0.05). while the intermediate benefited equally from self-regulation and Bandwidth feedback in transfer test (p>0.05).
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Background: 85% of multiple sclerosis patients suffer from impaired motor function and 65% from cognitive impairment. Therefore The main purpose of this study is to improve the cognitive and motor function of patients using dual tasks.... more
Background: 85% of multiple sclerosis patients suffer from impaired motor function and 65% from cognitive impairment. Therefore The main purpose of this study is to improve the cognitive and motor function of patients using dual tasks. Methods: The study samples were 60 women with MS (20-50 years) with an Expanded Disability Status Scale 2-4 and the duration of the period (10-14 years) who were divided into 4 groups and for eight weeks each week including two sessions 45 They practiced dual cognitive, motor, and individual training for 45 to 60 minutes. Data were analyzed by composite variance analysis at significance level of P <0.05. Results: The results of compound analysis analysis showed that the training of cognitive-motor tasks improved the significance of motor function (p = 0.0005) and cognitive performance (p = 0.0001) compared to the other three groups. Conclusion: The results of this study suggest that the physical benefits of training are always superior to cognitive changes. Dual-task training can be considered a good way to improve cognitive and cognitive function. Trial registration: This study was registered in the Iranian Clinical Trial Center with the number IRCT20200812048384N1, http://www.irct.ir/trial/50300, registered 26 August 2020.
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Introduction and goal: focus of attention and competition is an integral part of the sport and the factors affecting the performance and motor skills. The aim of this study was to examine the effect of the interaction of attentional focus... more
Introduction and goal: focus of attention and competition is an integral part of the sport and the factors affecting the performance and motor skills. The aim of this study was to examine the effect of the interaction of attentional focus types and competitive environmen on performance and learning over arm throwing in high school student.
Methodology: 60 male students with a mean age (16.95 ± 0/819) and unfamiliar with the research they were studying in Tabriz voluntarily participated in this study and were divided into four groups of 15 persons (external focus on non-competitive environment, internal focus on non-competitive environment, external focus on competitive environment, external focus on competitive environment). Then in the acquisition level practiced six blocks of ten attempts over arm throwing the earth tennis ball in conditions with each group. Retention and transfer tests were performed after 24 hours from the acquisition.
Findings: the results of variance analysis with repeated measures showed that the main effect of block groups and blocks, as well as the interaction between these two variables is significant. One-way analysis of variance and bonferroni test shows significant differences in all phases of the scores and in both competitive and non-competitive external focus group is better than internal focus group. The results also show that all groups in acquisition and retention tests compared to pre-test their progress (P≤0/05). Therefore, it is suggested that coaches and sports teachers in competitive environments also use external attention instructions to learn sport skills.
Methodology: 60 male students with a mean age (16.95 ± 0/819) and unfamiliar with the research they were studying in Tabriz voluntarily participated in this study and were divided into four groups of 15 persons (external focus on non-competitive environment, internal focus on non-competitive environment, external focus on competitive environment, external focus on competitive environment). Then in the acquisition level practiced six blocks of ten attempts over arm throwing the earth tennis ball in conditions with each group. Retention and transfer tests were performed after 24 hours from the acquisition.
Findings: the results of variance analysis with repeated measures showed that the main effect of block groups and blocks, as well as the interaction between these two variables is significant. One-way analysis of variance and bonferroni test shows significant differences in all phases of the scores and in both competitive and non-competitive external focus group is better than internal focus group. The results also show that all groups in acquisition and retention tests compared to pre-test their progress (P≤0/05). Therefore, it is suggested that coaches and sports teachers in competitive environments also use external attention instructions to learn sport skills.
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The aim of this study was to investigate the effect of contextual interference in implicit and explicit condition on the coordination and motor function in slow- learning children.For this purpose,60 slow- learning children with a mean... more
The aim of this study was to investigate the effect of contextual interference in implicit and explicit condition on the coordination and motor function in slow- learning children.For this purpose,60 slow- learning children with a mean age of12.28±0.80years where selected in available.After obtaining the terms of entry and consent, based on the pretest scores were divided into four groups(explicit practice without interference, explicit practice with interference,implicit practice without interference,implicit practice with interference).IQ was measured using Wechsler's Intelligence Test, fourth edition, bimanual coordination by the Vienna test and performance with a rotatory follow-up device. Then, the Four-session training (four blocks - nine attempts per session) was performed with a Pursuit rotatory in their special training sessions. After four sessions of training, the participants of the group were again measured in the above variables and the results were recorded as a post-test. For analysis of data, outcomes of the groups were analyzed by mixed analysis of variance 2(learning type)× 2(practice conditions) at post-test and retention stages at a significant level (p≤0.05).The results show that there is no difference between implicit and explicit learning in the acquisition and retention test (p<0.05).There is no difference between implicit and explicit learning in acquiring motor function (p<0.05).But in retention of motor performance, the difference between implicit and explicit learning was significant (p<0.05) and implicit learning showed better performance. In general, it can be said that in slow- learning children, the situation with the interaction of the implicit learning background leads to better memorization.
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Background & Purpose: Often, the beneficial effects of explicit and implicit instructions have been confirmed in past investigations. However, its lack of influence has been observed in some other studies. Therefore, contradictions in... more
Background & Purpose: Often, the beneficial effects of explicit and implicit instructions have been confirmed in past investigations. However, its lack of influence has been observed in some other studies. Therefore, contradictions in research results and failure to implement these guidelines are important in children with developmental coordination disorder. Therefore, the purpose of this study was to investigate the effect of the explicit and analogy instruction on motor learning in children with developmental coordination disorder.
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the aim of this study was to investigated The effect of monitoring and outcome pressure during decision making on the visual search behavior of football players. In this study, 18 soccer players employed in the Tehran youth premier league... more
the aim of this study was to investigated The effect of monitoring and outcome pressure during decision making on the visual search behavior of football players. In this study, 18 soccer players employed in the Tehran youth premier league participated. The decision making task included images of soccer simulation conditions presented by the monitor in three conditions: neutral (no pressure), outcome pressure and monitoring pressure. The result of repeated measures analysis of variance test showed a significant difference in the number of fixation and during fixation in three conditions. In addition, the Bonferroni post-hoc test showed a significant increase in mean number of fixation and mean duration fixation in outcome and monitoring pressure compared to neutral pressure.Therefore, soccer coaches are suggested to help the players in training sessions by creating pressure conditions so that they can perform better in the competition conditions by experiencing these conditions during training.
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Background Balance and maintaining posture are essential requirements for the daily activities of diabetic patients. The purpose of this study was to investigate the effect of in-water and on-land aerobic training on balance of type 2... more
Background Balance and maintaining posture are essential requirements for the daily activities of diabetic patients. The purpose of this study was to investigate the effect of in-water and on-land aerobic training on balance of type 2 diabetic patients.Research questionIs there a difference in the balance of patients between aerobic training environments in water and on land?Methods For this, 24 participants were assigned randomly in three eight-person groups of control, aerobics on land, and aerobics in water. Patients performed aerobic protocol in 12 weeks (2 sessions per week) and total of twenty-four 60-min training sessions of progressive challenging with one completely identical protocol. Before and after the training period, patients’ postural sway and balance were measured and recorded in three components (anterior-posterior, lateral, and overall) by Biodex balance system. Data were analyzed using the dependent t, multivariate, and Tukey post hoc tests.ResultsThe results showed that patients who performed in-water and on-land aerobic training, compared to the control group, had a significant effect on their balance (p ≤ 0.05). Although this significant effect was not observed between in-water and on-land aerobic groups just in the posterior-posterior component (p ≥ 0.05), there was a significant difference in lateral and overall components between these two experimental groups (p ≤ 0.05).SignificanceThe results showed that in-water and on-land aerobic training led to increased balance and decreased postural sways of diabetic patients. Also, in-water aerobics training compared to on-land aerobic training led to better effects on stability, consistency, and balance of patients due to increased stimulation of proprioception.
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Rope jumping enhances coordination, and doing joint rope jumping successfully requires precise temporal and spatial coordination. The aim of this study was to investigate the kinematic parameters in rope jumping and predict the... more
Rope jumping enhances coordination, and doing joint rope jumping successfully requires precise temporal and spatial coordination. The aim of this study was to investigate the kinematic parameters in rope jumping and predict the interpersonal coordination among students. In this applied study, the sample was 12 rope jumping elite girls (13-18 years old), selected using available sampling. The participants practiced various rope jumping tasks (individual and joint rope jumping in different distances with online landing) for one month until they could do them properly and without online feedback (Seeing or hearing each other). The researcher used a the Vicon motion analysis device with six infrared cameras capable of 120 frames per seconds to record three-dimensional movements of the legs and rope whirling. The results of one-way ANOVA showed that with enough practice, even in the absence of feedback, hand-foot deviation time and timing variation in rope whirling in joint groups had no significant differences while their movement time, jump height and landing position represented significant differences. The rope jumping, angular momentum and body vertical displacement are combined together. In the other hand, placement and timing are important. So, with increasing difficulty and demand of joint task, the intra-and interpersonal coordination level will enhance as well as coupling and anticipation power will be varied based on joint and individual task constraints.
Background: Mental exercise uses the same neuronal pathways involved in physical exercise to modify the pattern and function without the stress caused by physical exercise. This study investigated the effects of the three methods of... more
Background: Mental exercise uses the same neuronal pathways involved in physical exercise to modify the pattern and function without the stress caused by physical exercise. This study investigated the effects of the three methods of kinesthetic imagery, active, and combined exercise (imagery and active) on the pattern of hip hyperextension and the strength of selected muscle of lumbopelvic in women with lumbar hyperlordosis. Method: In this semi-experimental study, 36 women with lumbar hyperlordosis (age: 34.47±3.79, height: 160.48±12.63, weight: 64.46±18.26) were sorted into three groups. The groups practiced three sessions per week for six weeks. The degree of lumbar lordosis using flexible ruler, electromyographic activity of the lumbopelvic muscles during hip hyperextension in the prone position using surface electromyogram, the strength of the gluteus maximus during hip hyperextention using dynamometer, the strength of abdominal muscles during lowering two legs test using goniometer, flexibility of hip flexor muscles during the Thomas test using goniometer, and flexibility of erector spine muscles during the Schober test using a meter were measured before and after the intervention. The Shapiro-Wilk test was used for normality of data, and the repeated measures variance test was used for the statistical analysis of data at a significance level of 0.05. Results: The results showed a significant difference between the three methods of kinesthetic imagery, active and combined (P=0.001). There was a significant difference between the method of imagery exercise and the methods of active and combined exercise, but no significant difference was observed between the methods of active and combined exercise. Conclusion: Imagery exercises were effective in modifying the electromyographic activity of some lumbo-pelvic muscles (gluteus maximus and rectus femoris muscles); however, they did not have a significant effect on the strength, flexibility, or degree of lumbar lordosis. Combined exercise was as effective as active exercise in modifying the electromyographic activity of the lumbo-pelvic muscles, the strength of the abdominal and gluteus maximus muscles, and the flexibility of erector spine and hip flexor muscles.
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When misconducts outside the playing field occur by stakeholders of sport, penalties and fines are usually intended by sports clubs. However, if punitive actions were imposed by more formal entities such as the League organization or the... more
When misconducts outside the playing field occur by stakeholders of sport, penalties and fines are usually intended by sports clubs. However, if punitive actions were imposed by more formal entities such as the League organization or the Disciplinary Committee, it is likely that these votes will be challenged by the media. In recent years, more stringent disciplinary regulations have been introduced by the world's most prestigious sports leagues for the inappropriate behavior of athletes outside the field of sports and the number and severity of fines for offenders have increased. These punishments are considered with goals such as keeping a healthy environment, the development of healthy communication among sport stakeholders, support for professional ethics, educating good behaviors, providing a positive moral image of sports stakeholders, preventing league losses, and improving the reputation of the league and often beyond the framework of the players' contracts. However, factors such as the lack of defined hearing procedures, the reliance on public opinion in punishment, the magnitude of the misconduct of players, and the large difference in penalties in different leagues have raised questions about the competence and authority of professional sports leagues to punish players for abuse. This article analyzes how to punish misconducts of athletes outside the field of sports in the four major US sports leagues (including National Basketball, Basketball, Hockey, and Soccer), and with Iran’s Premier Football league and in particular, The way things are solved by the Football Federation's Ethics Committee is being compared and adapted.
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Purpose: The aim of the current study is to investigate the effect of active and passive imagery on the learning of the dart throwing skills in 7-12 years old student. Methods: So, in order to sampling, the motor imagery questionnaires... more
Purpose: The aim of the current study is to investigate the effect of active and passive imagery on the learning of the dart throwing skills in 7-12 years old student. Methods: So, in order to sampling, the motor imagery questionnaires for children were distributed among the statistical society (7-12 years old children) and 30 girls and 30 boys, whose imagery ability was similar, were chosen. After performing the pretest stage, samples were categorized into two groups: active homogenous group and passive homogenous group (2 groups of boys and two of girls). In order to determine differences between two mentioned groups, ANCOVA analysis test was used. Results: The first to sixth acquisition, learning and transition tests indicated that there are no significant differences in groups that are based on the interaction between sex and group. So, it can be inferred that the active and passive imagery did not influence the groups. Conclusion: Obtained results of acquisition, learning and transition stages showed that intellectual practices should be considered without regarding its type.
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Non-generic feedback refers to a specific event and that task performance is the reason to the acquisition of skills and implies that performance is malleable, while generic feedback implies that task performance reflects an inherent... more
Non-generic feedback refers to a specific event and that task performance is the reason to the acquisition of skills and implies that performance is malleable, while generic feedback implies that task performance reflects an inherent ability. The Goal of this study was to determine the generic and nongeneric feedback effects on children's motor learning basketball free throw. This research was semi-experimental. For this purpose, sixty children of Tehran (30 girls and 30 boys) aged 9-13 years participated in the study and were randomly divided into four groups of 15 individuals. Subjects performed six basketballs free throw in the acquisition (Two blocks of three trials). Which after the third throw, according to the group of subjects received a positive feedback (generic or non-generic) and also after the Sixth throw, negative feedback. After half an hour was immediate retention in the same way. Data were analyzed by using two-way ANOVA and repeated measures. Results showed that non-generic feedback was significantly more effective than generic feedback and shows more improvement in Performance. The present results demonstrate the importance of the wording of feedback, although these terms might not have an immediate effect on performance but by enhance motivation, poor performance is purportedly.
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Self-talk is one of the psychological factors influencing the improvement and success of motor performance. The present research aimed to investigate the effect of motivational self-talk on bimanual coordination of university students. 24... more
Self-talk is one of the psychological factors influencing the improvement and success of motor performance. The present research aimed to investigate the effect of motivational self-talk on bimanual coordination of university students. 24 students of physical education (12 females and 12 males, mean age = 22.62 and SD = 2.081) were selected by convenience sampling method. After the pretest, subjects were divided into two homogeneous groups of motivational self-talk and no self-talk using bimanual coordination tester. For data analysis, descriptive and inferential statistics including independent t test and paired t test were used at 0.05 significance level. Results showed that self-talk improved the coordination performance significantly (p < 0.05). Also, the female group had a significantly better precision in bimanual coordination (p < 0.05) and the male group had a significantly better speed in bimanual coordination (p < 0.05). But, there was a significant difference between boys and girls in self-talk group in the posttest (p < 0.05). According to these findings, it is suggested that motivational self-talk should be used to improve and promote bimanual coordination performance.
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The mechanism and neural origin of the differences between the two hands in motor control and learning are still unknown. The aim of the present research is to examine the changes in synergy patterns in different brain regions while... more
The mechanism and neural origin of the differences between the two hands in motor control and learning are still unknown. The aim of the present research is to examine the changes in synergy patterns in different brain regions while learning the dart throwing skill with the dominant and non-dominant hand. The sample population consisted of 10 students aged 23±2.5 divided into two groups of dominant and non-dominant hand. To record brain activities, a 32-channel wireless Electro-encephalography (EEG) system was used. Data were recorded through three stages of pre-test (pre-training), acquisition (after 4 weeks of training) and retention (after one week of non-training). EEG signals were analysed in alpha, beta and gamma bands. EEG analysis showed that the synergy patterns during acquisition and retention stages were significantly similar to each other and largely different from the pre-training stage in all three bands. Increasing activity levels of the contralateral cortical areas and formation of a different activity pattern after learning in the two groups, were other results obtained. Learning a new motor skill requires relatively lasting changes in the brain map and synergy patterns of brain activities are different for motor learning when the dominant or non-dominant hand is used.
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Measuring instrument of interpersonal and intrapersonal motor coordination has designed and built to provide information about the human movements' coordination in reach of researchers, trainers and therapists. To evaluate the validation... more
Measuring instrument of interpersonal and intrapersonal motor coordination has designed and built to provide information about the human movements' coordination in reach of researchers, trainers and therapists. To evaluate the validation of this instrument with using of Vienna two hands coordination test and present research instrument were asked 28 participants to do the task of two hands, two feet and interpersonal movement coordination. Pearson correlation test showed that the present research instrument has high validation in motor coordination of two hands in total time mean factor of joystick (r =0/88), knob (r =0/96) and in error percentage mean factor of joystick (r =0/89) and knob (r =0/87). Also the results of Cronbach's alpha showed that present research instrument has appropriate reliability in motor coordination of two hands in total time mean factor of joystick (r =0/89) and knob (r =0/97) and in error time percentage mean factor of joystick (r =0/81) and knob (r =0/85). Also results indicated acceptable reliability in motor coordination of two feet in total time mean factor of pedals (r =0/90) and in error time percentage mean factor of pedals (r =0/83) and in interpersonal motor coordination in total time mean factor (r =0/91) and in error time percentage mean factor (r =0/80). Therefore using the present study instrument can be offered to sports science laboratories in all higher education institutions, federations and coaches, patients and rehabilitation centers, health and physiotherapy clinics.
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Purpose: Virtual reality environments are used as an effective intervention in motor skills training. The purpose of this study was to determine the effect of virtual reality training on self-efficacy of male students. Methods: The... more
Purpose: Virtual reality environments are used as an effective intervention in motor skills training. The purpose of this study was to determine the effect of virtual reality training on self-efficacy of male students. Methods: The statistical sample of this study were 36 male students who were selected as available samples and divided into three; Functional constraint virtual training, Structural constraint virtual training, and Real world training groups. The present study was conducted in three sessions of pre-test, training and post-test. Dart throwing skill was selected as the task. Special dart's self-efficacy questionnaire was completed by the students and collected. Results: The results showed that virtual training of dart significantly improves students' self-efficacy, and there is no significant difference between the effects of training groups on self-efficacy. Conclusion: Therefore, virtual reality system can enhance the self-efficacy of sports skills.
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Cognitive constrain of individual constrains which can be created with imagery and is a factor in many tasks affecting the performance has been investigated. Thus, the aim of the present study was to investigate the effect of PETTLEP... more
Cognitive constrain of individual constrains which can be created with imagery and is a factor in many tasks affecting the performance has been investigated. Thus, the aim of the present study was to investigate the effect of PETTLEP imagery on the accuracy and speed basketball pass skill. 44 female students of Faculty of Physical Education, University of Tehran (mean age of 22.45±2.3 years) were selected by convenience sampling method and participated in this study. In pretest, participants performed 2 blocks of 10 trials of accuracy and speed basketball pass. Then, they were assigned to one of the four groups homogeneously: accuracy pass PETTLEP imagery, speed pass PETTLEP imagery, accuracy control, and speed control. Two groups of imagery listened to the imagery audio during 3 days for 8 minutes per day. Then, subjects participated in posttest, retention and transfer tests. For data analysis, mixed ANOVA was used. In case of significance, independent t test was used for intergroup comparisons and analysis of variance with repeated measures was used for within-group comparisons with significance level of α=0.05. The results of analysis of variance indicated no significant differences between imagery and control groups in pretest. However, there were significant differences in posttest, retention and transfer tests between imagery and control groups (P≤0.05). Also, PETTLEP imagery of accuracy and speed pass improved accuracy and speed pass performance from pretest to retention test; however, there was no such process in transfer test (P≥0.05).
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Various studies have shown that the external focus of attention is better than the internal focus of attention. But, so far no study has been investigated the level of electrical activity of the rectus abdominus muscle as a trunk... more
Various studies have shown that the external focus of attention is better than the internal focus of attention. But, so far no study has been investigated the level of electrical activity of the rectus abdominus muscle as a trunk stabilizer muscle. Therefore, the purpose of this study was to investigate the effect of focus of attention on electromyography activity of the rectus abdominus muscle during Different phases of vertical jump.Twelve male elite volleyball players from university of Tehran Participated in this research voluntary. They performed a vertical jump on the force plate in both internal and external focus of attention condition. Rectus abdominus Surface electromyography (SEMG) signals recorded by electromyography apparatus during vertical jump and The electrical activity of this muscle was calculated in the different phases of vertical jump motion. Paired t-test results showed that height of jump under the external focus was higher than the internal focus. In addition, this results showed that internal focus caused significant increasing in Rectus abdominus EMG in comparison to external focus during concentric phase. But, there was no significant difference in the eccentric phase between the external and internal focus of attention conditions. These results suggest that the external focus of attention effectively increases the efficiency of vertical jump. Therefor; we recommend using the external focus of attention instructions when executing vertical jump movement.
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Different studies have shown the advantage of the external focus of attention using relatively simple variables. The aim of this study was to investigate the constrained action hypothesis by underlying neurophysiological mechanisms tests... more
Different studies have shown the advantage of the external focus of attention using relatively simple variables. The aim of this study was to investigate the constrained action hypothesis by underlying neurophysiological mechanisms tests of the lower extremity muscle in vertical jump under the impression of Focus of Attention Types. For this purpose, 12 male professional volleyball players (mean age: 24±1.92, mean weight: 73.5±8.7) performed a vertical jump on the force plate under two conditions in a counterbalanced order: external focus and internal focus. EMG activity of the lower extremity muscle was measured during jumps by using EMG device that coupled with force plate. Paired t-test results showed height of jump under the external focus was greater than that of the internal focus, while there were no significant differences in onset and offset times of the muscles activity between attentional focus conditions (onset times:(P=0.085), offset times:(P=0.08)). Also, the results show significant increases in EMG of the lower extremity with internal focus during concentric phase (P=0.005). However, there was no significant difference in EMG of these muscles between the internal and external focus in the eccentric phase (P=0.069). These results suggest that the intermuscular of coordination are not affected by the focus conditions but the intermuscular coordination is enhanced by the external focus of attention and the external focus of attention increase develop more automation of motor control.
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The purpose of the study was to investigate the psychological pathology and the use of legal and illegal sports supplements in female athletes. This research was descriptive-analytic and is in the cross sectional study. 485 participants... more
The purpose of the study was to investigate the psychological pathology and the use of legal and illegal sports supplements in female athletes. This research was descriptive-analytic and is in the cross sectional study. 485 participants completed questionnaires including background information, attitude and knowledge about the use of supplements, and a short form of self-concept questionnaire with an internal consistency of 0. 90 and time reliability of 0. 83. Descriptive statistics were used to determine the central tendency indicators. About 24% of athlete women used sports supplements, 61% of them have had constant attention to authorized and unauthorized supplements. More than 20% have been used only with their coach confirmation. The results showed a significant relationship between physical self-concept and sport supplement consumption. Also due to the low level of recognition of women, it is possible to prevent the effects of these drugs more effectively through appropriate training on the harmful effects of them.
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Variability is discussable topic in skilled execution, therefore; the aim of the present study was to investigate coordination variability between missed and successful chip pass skill between expert soccer players under variation of the... more
Variability is discussable topic in skilled execution, therefore; the aim of the present study was to investigate coordination variability between missed and successful chip pass skill between expert soccer players under variation of the task constraints. Participants included 10 right-footed soccer men in the age 22.06 ± 1.41 years' old. They performed 10 passing soccer chips in different height of the barrier and various distances of ball to barrier and target (task constraints). Waterloo Footedness Questionnaire was used to determine of dominant foot and a 7-point Likert scale was used to evaluation of performance accuracy. Vector coding method was used to measure of motor coordination variability for recorded kinematic data form joints of the ankle, knee and hip of the kicking foot. All variables were found to be normally distributed (Shapiro Wilks > 0.05). Analysis of variance with repeated measures was used to compare kinematic data between missed and successful trails (P≤0.05). Results showed that significant difference exist in the ankle-knee couplings between missed and successful trails in the first (Ball distance to target 10 meters and the height of barrier 1.5 m) and second (Ball distance to target 12 meters and the height of barrier 1.7 m) statuses (P= 0.01). While in the hip-knee couplings no significant difference exists between missed and successful trails in the first and second statuses (P= 0.61), (P= 0.36). The results indicate that probably skilled in their successful trails are capable to benefit of inherent variability of the system functionally for optimal organization of the task constraints and improve motor performance.
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Background and Aims: The purpose of the present study was to investigate the effect of three methods of kinesthetic imagery, active, and combination exercises on electromyographic pattern of femur hypertension in women with hyperlordosis.... more
Background and Aims: The purpose of the present study was to investigate the effect of three methods of kinesthetic imagery, active, and combination exercises on electromyographic pattern of femur hypertension in women with hyperlordosis. Materials and Methods: In the current investigation, 36 women with lumbar hyperlordosis were chosen and divided into three groups of imagery, active and combined exercises. The groups trained for six weeks, three times a week. The lumbar lordosis was measured making use of flexible ruler and electromyographic activity of the selected muscles of pelvic in the femur motion in prone condition using surface electromyogram before and after the intervention. Results: There was a significant difference between the three training methods (P = 0.005). Conclusion: According to the results, combination exercises were effective in changing pelvic muscle activity; therefore, it is suggested that kinesthetic imagery exercises be used along with physical exercises to correct abnormalities.
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Background: Games play an important role in nurturing children's creativity. The important question is: Do stretching games affect children's creativity? Aims: To compare the effect of stretching games on increasing the creativity of boys... more
Background: Games play an important role in nurturing children's creativity. The important question is: Do stretching games affect children's creativity? Aims: To compare the effect of stretching games on increasing the creativity of boys and girls. Method: The research method was quasi-experimental. The statistical population consisted of 2978 students studying in kindergartens of 1,6,12 districts of Tehran. 341 persons including 153 girls and 188 boys were selected through random sampling. The tools include the Torrance (1974) Creative Thinking Practice and Motion Test and the Torrance (1974) Creative Thinking Practice Test. Data were analyzed using independent t-test. Results: Creativity was more effective in boys than boys' traction games (0/05). Conclusions: Stretching games can have a positive effect on enhancing children's creativity.
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The purpose of this study was to investigate the effect of colors and gender on the Coincidence anticipation timing task. Therefore 60 participants aged 8 to 10 years randomly into two groups (30 males and 30 females) participated and... more
The purpose of this study was to investigate the effect of colors and gender on the Coincidence anticipation timing task. Therefore 60 participants aged 8 to 10 years randomly into two groups (30 males and 30 females) participated and timing error was recorded by a coincidence-anticipation apparatus. For data analysis independent t-test,ANOVA and Tukey post hoc tests were used at the significant level of 0/05. Findings suggested no significant difference between boys and girls in coincidence anticipation timing task (p=0/289) and the lowest timing error in a blue background and also significant difference timing errors were observed between the blue background, with other color (P=0/001 and F(2,59)=22/17). The results of this study indicate that gender does not affect on the Coincidence anticipation timing task and the performance in background color blue can reduce timing errors in predicting the spatial and temporal stimuli. In genral the results of this study indicated that gender didn,t affect the Coincidence anticipation timing task and the blue background color would facilitate the performance and effectiveon reduce errors timing in stimuli predicting spatially and temporally. The purpose of this study was to investigate the effect of colors and gender on the Coincidence anticipation timing task. Therefore 60 participants aged 8 to 10 years randomly into two groups (30 males and 30 females) participated and timing error was recorded by a coincidence-anticipation apparatus.
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The aim of this study was to evaluate of three observational exercise methods, including immediate, interspersed and combination exercise on performance of ju-no kata karate form. For this purpose, 45 adolescents 9-12 years old based on... more
The aim of this study was to evaluate of three observational exercise methods, including immediate, interspersed and combination exercise on performance of ju-no kata karate form. For this purpose, 45 adolescents 9-12 years old based on inclusion and exclusion criteria for the study voluntary Participated and based on self- Efficacy sport questionnaire event in three groups were matched. Immediate imitation group (15) after each viewing model start the physical effort and imitate the model. Interspersed imitation group (15) carry out the first of ten attempts to coincide with the viewing model, then 2 to 5 working next run without viewing model and the 6th effort run same as the first effort, then 7 to 9 working next run without viewing model and finally 10th effort coincide with the viewing model. Combination exercise group (15) implemented five first attempt to coincide with the viewing model, then effort 6 to 9 without viewing model and finally 10th effort coincide with the viewing model. All groups, for four weeks, 12 session (three sessions per week) to the above mention methods combine their physical and observational training. At the end, acquisition test, and retention test within 48 hours without practice and transfer test conducted with stressful situations in performance of duty Accomplished. The result of multivariate analysis of variance showed that all three observational practice methods have helped to improve the performance and the retention and transfer tests also remained stable progress. Comparing groups also lead to immediate imitative exercise group compared to the other two groups, Of course, imitation combination exercise group to compare with imitation interspersed exercise group was Premier, In addition cover the difference in the retention and transfer tests were also sustained
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Background: A quiet eye is the final fixation or tracking before moving on, which requires concentration and attention, and is an effective way of teaching interceptive tasks. Methods: In the current semi-experimental study, 20 volunteer... more
Background: A quiet eye is the final fixation or tracking before moving on, which requires concentration and attention, and is an effective way of teaching interceptive tasks. Methods: In the current semi-experimental study, 20 volunteer female students from a volleyball center of Shiraz District 1 (mean age = 12.10, SD = 0.718) were selected as the participants from February 2017 to February 2018. After taking the pre-test, they were randomly divided into two groups of 10 (technical training and quiet eye training). The intended task was to receive volleyball serve with the forearm from three receiving areas of the mini-volleyball court. To measure the accuracy of the volleyball serve reception, a volleyball Serve Reception Test by forearm was used in mini-volleyball court. Ergoneers eye tracking (EET) was used to record the visual data. After the pre-test, the participants took part in 9 separate training sessions three sessions a week, and 48 hours after the last training session, the first retention test and one month later the second retention test was performed. Data were analyzed by 2 × 3 mixed analysis of variance (ANOVA) of quiet eye duration and performance, using SPSS software at a significant level of P ≤ 0.05. Results: The results showed that the mean performance of the quiet eye training group increased from 4.30 ± 1.76 in pre-test to 11 ± 1.76 in the first retention and 12 ± 2 in long-term retention in comparison to the technical training group (P = 0.007). However, there was no significant difference between the mean quiet eye duration of the quiet eye and technical training groups (P = 0.512). Conclusions: It seems that quiet eye training has a significant effect on the long-term learning of beginners compared to technical training, but it does not have a significant difference in the duration of beginners' quiet eye compared to technical training.
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The movement imagery helps to learn various sports skills if persons have a reasonable imagery about how doing that skill and the command be carved on the brain. The main aim of the current study is to investigate the visual and content... more
The movement imagery helps to learn various sports skills if persons have a reasonable imagery about how doing that skill and the command be carved on the brain. The main aim of the current study is to investigate the visual and content validity as well as the reliability of the Persian version of the Movement Imagery Questionnaire for Children MIQ-C. The main questionnaire was translated into the Persian by using the Translation-back Translation method. In order to standardize and validate the questionnaire, 10 elites in the field of the motor imagery and sports psychology, filled the questionnaires in order to determine the content validity ratio (CVR) and the content validity index (CVI). After a primitive study, the necessary modifications were applied.The questionnaire reliability was investigated by the test-retest reliability method and the Cronbach's alpha. Results indicated that the CVR and CVI are 0.62 and 0.79, respectively, which confirms the validity of the questionnaire. The reliability was confirmed by the internal consistency method which value was obtained higher than 0.7. For evaluating the ability of children in motor imaginary, a reliable method should be used.According to obtained results of the current work, the questionnaire benefits from a suitable reliability and validity.
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The aim of this study is to investigate the effect different levels of exercise intensity and arousal has on the speed and the accuracy of decision making among expert female soccer players. Methods: Sixteen expert female soccer players... more
The aim of this study is to investigate the effect different levels of exercise intensity and arousal has on the speed and the accuracy of decision making among expert female soccer players. Methods: Sixteen expert female soccer players with at least 8 years competitive background were selected voluntarily participate in this study. Soccer experiment images were displayed on a screen where the participants had to choose a response from three options (shoot, pass, and dribble) in order to assess the decision making performance. The test experiments were designed in three arousal and three exercise intensity levels. In order to examine any significant effect of the levels of different situations, a One-Way ANOVA with Repeated Measures was performed to find the effects of mentioned variables on the accuracy and the speed of decision making. Results: The results obtained from the present study did not reveal any significant effect of level of arousal on the speed of decision making (p>0.05). The accuracy of decision making, however, was significantly affected by the exercise intensity (p<0.05). With increasing the exercise intensity, the players' speed of decision making showed an improvement with no spectators and the presence of inactive spectators at different levels of arousal. It was only at the exercise intensity level of 80% max HR that the best accuracy of decision making was observed at the presence of inactive spectators. Conclusion: The present findings suggest that the level of arousal and the exercise intensity affect each of decision-making components separately.
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Purpose Parkinson's disease (PD) is one of the most common neurodegenerative disorders. This study compared the effects of two types of exercises on motor dys-function in characterizing adult male Wistar rats with unilateral... more
Purpose Parkinson's disease (PD) is one of the most common neurodegenerative disorders. This study compared the effects of two types of exercises on motor dys-function in characterizing adult male Wistar rats with unilateral 6-hydroxydopamine lesions placed in the median forebrain bundle. Methods Sixty adult male Wistar rats were randomly assigned to six groups: the control intact and Parkinson group (no exercise), the forced group (sham, PD), the voluntary group (sham, PD). The effects of 4 weeks of forced treadmill running and voluntary wheel running on motor behavior were investigated in the open field, Rotarod and hanging tests. Results The outcomes showed that although the length moved by the voluntary exercise group was more than that in the forced exercise, the forced exercise resulted in better performance in Rotarod (P = 0.01), whereas voluntary exercise was found to increase rearing behavior (P = 0.01). Both exercise groups were the same in the open field (p [ 0.05), grooming frequency (P = 0.12), and hanging test (P = 0.181). Conclusion We found that wheel running and treadmill running exercise protocols improved the motor impairments in the 6-OHDA-lesioned rat model of Parkinson's disease; therefore, our result suggests that both exercise methods could be beneficial for PD patients to reduce their motor dysfunction.
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Parkinson’s disease (PD) is a neurodegenerative disease characterized by progressive and loss of dopaminergic neurons in the SNpc. Behavioral symptoms and cognitive impairments even dementia are common in Parkinson disease. Physical... more
Parkinson’s disease (PD) is a neurodegenerative disease characterized by progressive and loss of dopaminergic neurons in the SNpc. Behavioral symptoms and cognitive impairments even dementia are common in Parkinson disease. Physical activity impacts functional recovery in humans, however, its effects in experimental animals submitted to Parkinson model have been inconsistent. The present work was focused on the neuroprotective effect of 4 weeks voluntary exercise (wheel running) against experimentally (6-OHDA) induced Parkinson’s disease in rat, by analyzing the memory and learning. Morris water maze test was used for measurement of spatial learning and memory. Results did not demonstrate any main effect differences between the exercise and control groups on weight gain (p > 0.05). 6-OHDA injection caused a significant cognitive deficit in spatial water maze tasks and this effect was reversed in rats after receiving exercise protocol. Voluntary exercise improved the cognitive performance in both reference and working spatial memory against 6-OHDA administration (p < 0.05). We suggest that voluntary exercise interventions may has the potential role in promoting neuroplasticity and repair cognitive dysfunction in Parkinson’s disease (PD).
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Abstract: (1219 Views) Aims: Cognitive disorders is one of the problems of veterans with post-traumatic stress disorder (PTSD). The current study aimed at investigating the effects of aerobic exercises on memory and attention in veterans... more
Abstract: (1219 Views) Aims: Cognitive disorders is one of the problems of veterans with post-traumatic stress disorder (PTSD). The current study aimed at investigating the effects of aerobic exercises on memory and attention in veterans with PTSD. Materials & Methods: The present semi-experimental study with pre-test post-test design and control group was conducted in 2016 among 21 patients with PTSD, who were referred to Boostan Psychiatric Hospital in Ahvaz. The subjects were voluntarily selected through purposive sampling method and, then, randomly divided into two groups: aerobic exercise (n=11) and control (n=10) groups. The exercises were performed for 8 weeks, 3 sessions a week. Memory level was measured by Wechsler questionnaire and attention level was measured by strop test. The data were analyzed by SPSS 22, using dependent and independent t-tests. Findings: In the aerobic exercise group in the post-test stage, there was a significant difference between the mean scores of all Wechsler memory subscales and the level of attention (p<0.05), while there was no significant difference in the control group (p>0.05). There was a significant difference between the exercise group and the control group (p<0.05). Conclusion: Aerobic exercises are effective in improving memory performance and attention in patients with PTSD. Keywords: Post-traumatic stress disorder, Aerobic Exercises, Memory, Attention
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Background: Various theoretical approaches have different views regarding the role and importance of vision information in the production and control of movements, but how vision control mechanisms act under anxious conditions? Aims: The... more
Background: Various theoretical approaches have different views regarding the role and importance of vision information in the production and control of movements, but how vision control mechanisms act under anxious conditions? Aims: The present research aimed to evaluate vision control mechanisms under anxious conditions in novice golf players. Method: In this quasi-experimental study, 20 novice golf players were selected through convenience sampling in the city of Isfahan. The task of the current study was the performance of golf-putting skill under different anxious conditions (baseline vs. anxiety). In this study, participants in the baseline and anxious conditions performed 6 trials of counterbalance in each condition without blocking (control), the first phase blocking, and the last phase blocking of movement in each task. Simultaneously with golf-putting performance, the quiet eye data were recorded by an eye tracker system. Data were analyzed via two-way ANOVA and Tukey’s post hoc statistical methods. Results: The results indicated that participants’ quiet eye significantly decreased under anxiety conditions (p=0/0001). Also, the results showed that the initial blockage of movement caused further weakening of the accuracy and quiet eye compared to the final blockage of movement (p=0/0001). Conclusions: Overall, the results of the current study emphasize the pre-programming system in the performance of golf-putting skill in novice golf players.
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Anticipation skill is a strategy to reduce the response time or even reduce the processing steps that is normally used to response to a stimulus. The aim of the present research is designing and building software that has the ability to... more
Anticipation skill is a strategy to reduce the response time or even reduce the processing steps that is normally used to response to a stimulus. The aim of the present research is designing and building software that has the ability to measurement accuracy of temporal anticipation. To check the validation, 30 participants (male students) who participated voluntarily from the Faculty of physical education of Tehran university. Executive software environment dimensions and speed of stimulus and Length of stimulus path are according to fit the dimensions of Digital type speed anticipation reaction tester. With the difference that a few other speed options we've added in software. The software is designed in such a way that uses automatically maximum amount of screen size. The distance of person from screen is calculated proportional to the speed anticipation device manually. For the validity and reliability, we use correlation of Pearson assessment between application data with Digital type speed anticipation reaction tester model (TAKEI_1108). In determining the validity of software, Pearson correlation analysis results did not show a significant difference between the parameters of the software and the device and the highest level of correlation is reported for the slow speed r = 0.84 and fast speed r = 0.86. In determining the validity, the Pearson correlation did not shown a significant difference between the parameters of the two tests and highest correlation is reported for fast speed r = 0.90 and 0.91 for slow speed. According to what was said it is concluded that the “anticipation timer software “is software that with the high amount of validity and reliability, estimate the anticipation speed skill.
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The aim of this study was to investigate the emergence of special skill in basketball free throw at different skill levels based on Newell's model of learning stages. Participants were assigned to three skill groups (n=10): coordination... more
The aim of this study was to investigate the emergence of special skill in basketball free throw at different skill levels based on Newell's model of learning stages. Participants were assigned to three skill groups (n=10): coordination group, coordination control group, and optimization group. They threw 350 fixed shots from 7 parametric points (2.74, 3.35, 3.96, 4.57, 5.18, 5.79, 6.4), carrying out 50 shots in each point. Regression analysis showed that the accuracy of those who were in the third stage of Newell's model in 4.57 m point, which is the same line of penalty, was significantly higher than the anticipated regression equation and supported the emergence of special skill (P>0.05), but the rest of the points did not follow the principles of force variability and performance accuracy decreased by increasing distance parameter. Moreover, multiple regression analysis showed that the rest of the points had no contribution to the emergence of special skill and this conclusion may be the reason for rejecting generalized theory in the creation of special skill.
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The purpose study was to investigate the effect type of attentional focus and the frequency of feedback on explicit knowledge and learning of Basketball free throwing. Fifty students were selected by accessible sampling method as a... more
The purpose study was to investigate the effect type of attentional focus and the frequency of feedback on explicit knowledge and learning of Basketball free throwing. Fifty students were selected by accessible sampling method as a research sample. Subjects after the pretest randomly assigned to five experimental groups (internal focus feedback with frequency of 100%, internal focus feedback with frequency of 33%, external focus feedback with frequency of 100%, external focus feedback with frequency of 33% and control). At the acquisition phase, Experimental groups conducted six blocks of ten attempts (each day, two blocks of ten attempts and a total of 60 attempts) per week and in three training sessions so that received attentional focus related to feedback (internal or external) with the relevant frequency (33% or 100%). After72 hours, the retention and transfer tests with blocks of ten attempts and measurement of explicit knowledge of subjects was done. Accuracy of throwing by Hardy and Parfit method (1991) and explicit knowledge by questionnaire was evaluated. ANOVA with repeated measure showed a significant effect on the block in all experimental groups except the control group (P<0/05). Significant difference was found between the research groups in the retention and transfer tests (P < 0.05). There was a significant difference between type of explicit knowledge of the external and internal focus groups (P < 0.05). But there was no significant difference between of them (P > 0.05). The findings showed that the significant accumulation of external explicit knowledge in the external focus feedback groups prevents breakdown of automated processes.
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In the present study, decision making behaviors of elite soccer players at three exercise intensities (rest, 40% maximum and 80% maximum) and three motivational situations (low, moderate and high) were assessed. 14 elite male soccer... more
In the present study, decision making behaviors of elite soccer players at three exercise intensities (rest, 40% maximum and 80% maximum) and three motivational situations (low, moderate and high) were assessed. 14 elite male soccer players with minimum 8 years of playing experience participated in this study (mean age 23/07). Data was analyzed using factorial analysis of variances and repeated measures at significance level of P<0/05. When arousal was medium or high, increasing the exercise intensity was due to decline in accuracy of decision making (P=0/045, P=0/001). But when the arousal was low, there was no difference in accuracy of decision making under three different exercise intensity (P=0/116). Hence, decision making behavior in elite players is affected by interaction of player and environmental constraints during try for reaching specific functional goal.
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The purpose of present study was to investigate monitoring pressure on decision making and relate it to decision specific reinvestment. Subjects were 25 expert Ping-Pong players in which they performed a Ping-Pong simulated decision... more
The purpose of present study was to investigate monitoring pressure on decision making and relate it to decision specific reinvestment. Subjects were 25 expert Ping-Pong players in which they performed a Ping-Pong simulated decision making task using option generation method under two conditions of low and monitoring pressure. Also, the Persian version of decision specific reinvestment scale and competitive sport anxiety inventory-2 were used. Results of multivariate analysis of variance with repeated measure revealed that pressure had a significant effect on cognitive anxiety (P≤0.05). Also, the results revealed that there were significant differences between some decision-making variables including first option quality, dynamic inconsistency and generation time under low and monitoring pressure (P≤0.05). Decision reinvestment only could predict the first option quality changes. Thus coaches and athletes are offered to have knowledge about the different pressure conditions and expert athletes to avoid the self-focus intentions under pressure.
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Background: Providing feedback with self-controlled methods has improved the performance and learning of motor skills as a result of the motivational effects and the deeper processing of related information. despite extensive research on... more
Background: Providing feedback with self-controlled methods has improved the performance and learning of motor skills as a result of the motivational effects and the deeper processing of related information. despite extensive research on self-inhibition feedback, can it be said that this type of feedback, verbally, can influence the pattern of movement? Aims: The purpose of this study was to investigate the effect of self-controlled practice on the performance of female student basketball shooters. Method: This is a semi-experimental study and its design is pre-test and post-test with control group. Participants of this study were 20 female students who were randomly divided into two self-controlled and yoked groups. Research was conducted in 5 sessions consisted of a pre-test session before the beginning of the exercise, 3 sessions of practice and one post-test session. Films were taken from the pattern of throwing the Subjects, then the films were evaluated by three instructors. Results: Findings of the independent t-test showed a significant difference between groups' acquisition (P= 0/025) and retention (P= 0/035) mean score. Both groups had significant progression from pre-test to post-test, and according to the data, the self-controlled group had a significant difference compared to the yoked group in the post-test. Conclusions: Using self-controlled practice which leads to internal motivation, enhancement of self-efficacy, personality independence, anxiety and stress decrease coaches can create optimal conditions for practicing and provide conditions for obtaining a better pattern of movement in practice.
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Purpose The basal ganglia have long been implicated in motor and cognitive function. Previous research has shown that regular forced treadmill running improves cognitive performance especially learning and memory. In this study, we... more
Purpose The basal ganglia have long been implicated in motor and cognitive function. Previous research has shown that regular forced treadmill running improves cognitive performance especially learning and memory. In this study, we examined the role of mild forced treadmill exercise on spatial learning and memory, and motor activity. Methods 56 male Wistar rats were randomly split into seven groups. Animals received ibotenic acid infusions into striatum bilaterally. Spatial learning and memory for all rats were evaluated by Morris water maze test. On the following day, visible and probe tests were performed for all groups. Motor activity of rats was assessed by open-field apparatus. Results Our results showed that animals with striatal lesion were much slower at finding the platform. Mild treadmill exercise during training could decrease the distance traveled to find the hidden platform. While exercise has shown to improve learning/memory, it has not been able to completely treat the impairment caused by ibotenic acid injection into the striatum. Results of open-field test were congruent with the Morris water maze test, with exercise animals displaying higher levels of motor activity. Conclusions The present results suggest that striatum has a critical role in spatial learning and memory. However, mild treadmill exercise could not improve impaired spatial learning and memory in rats with striatum lesion.
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Background: Numerous studies proposed the improvement of movement skills on sport-context by virtual reality interaction. Objectives: The purpose of this study was investigating the effect of virtual reality on dart throwing performance... more
Background: Numerous studies proposed the improvement of movement skills on sport-context by virtual reality interaction. Objectives: The purpose of this study was investigating the effect of virtual reality on dart throwing performance and kinematics. Methods: A total of 24 healthy junior high school boy students (aged = 13.54, SD = 0.50) participated in a virtual reality game of dart throwing in the Iranian academic year of 1396-97. We investigated the mean radial error and bivariate variable error to measure performance outcomes, and preparation time, throwing time, maximum flexion angle, release time angle, and angular velocity to measure movement kinematics. The X-box Kinect (Microsoft, USA) body movement track, standard dart board (unicorn ELIPSE HD) and Casio High-Speed camera (EX-ZR1000, China) sampling at 240 Hz were used to measure performance and capture dominant upper limb motion during dart throwing play. Before exporting data to SPSS 25, Kinovea and MATLAB R2015b were used to analyze videos and smoothing data. Repeated measure ANOVA was used to analyze variables separately. Results: The results showed that virtual reality intervention was significantly effective on performance and movement kinematics. Mean radial error (P = 0.004) decreased from 19.67 ± 6.20 in the pre-test to 17.46 ± 5.81 in the acquisition, and 14.75 ± 4.01 in the post-test. Bivariate variable error (P = 0.001) decreased from 11.46 ± 1.21 in the pre-test to 11.20 ± 1.56 in the acquisition, and 10.03 ± 1.11 in the post-test. Other kinematics factors showed the significant difference in phases. Conclusions: These findings suggest that virtual reality can be applied as an effective instrument in discrete motor skill learning.
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Behavioral studies in team sports is typically constrained by dynamic factors, such as positioning of defenders for interception. In this study were captured data from the movement velocity with high speed camera, throwing velocity with... more
Behavioral studies in team sports is typically constrained by dynamic factors, such as positioning of defenders for interception. In this study were captured data from the movement velocity with high speed camera, throwing velocity with sports radar gun and throwing accuracy of 12 elite handball players under defensive constraints (defender- absent, defender-far, defender-near, and defender pairing). ANOVA with repeated measures and Bonferroni post hoc test was used to analyze effects of these constraints on gait and throwing parameters (P<0.05). The results revealed significant differences in overall mean horizontal velocity (F(1.335,14.682) = 8.680, P = 0.007 ) and mean ball velocity ( F(3,33) = 12.733, P = 0.000 ) but there was no significant differences in mean ball accuracy ( F(3,33) = 0.400 , P = 0.754 ). When defender was closer to the attacker, mean movement velocity and throwing velocity was shown more decrease. Since regulation of offensive players was continuous and based on perception of current and required behaviors, results supported from perception-action coupling and prospective control models. Also, findings suggest that the technical aspects of the running and throwing in handball can affect by nested tasks constraints.
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Introduction: Quiet eye had been introduced as a period of extended gaze fixation in many targeting tasks. The aim of this study was to investigate the effect of quiet eye training with self-control and constant-variable body organization... more
Introduction: Quiet eye had been introduced as a period of extended gaze fixation in many targeting tasks. The aim of this study was to investigate the effect of quiet eye training with self-control and constant-variable body organization on performance and learning badminton low backhand service in the student novice girls. Materials and Methods: In this quasi-experimental study, 19 girl students of physical education in University of Tehran, Iran, were selected using convenience sampling method and randomly divided into two groups of selfcontrol (n = 9) and constant-variable (n = 10). The task intention was badminton backhand low service. In order to measure the accuracy of backhand low service, we used French short serve standard five test, and to record the visual data, Ergonear Eye Tracking test was used. The day after the pretest, participants took part in 3 sections of acquisition (8 blocks with 15 trails, a total of 360 trails), and 48 hours after the acquisition test, the test of retention and transfer was executed. The data were analyzed using Mixed ANOVA test of 2 × 4 at performance and 2 × 3 during the period of the quiet eye at a significance level of P ≥ 0.050. Results: Quiet eye duration showed a significant increase in both groups from pretest to retention (P ≥ 0.001). Therefore, it can be noted that both methods of practice had a positive effect on the quiet eye duration. However, in the accuracy performance, there was no significant different between the groups (P = 0.374) and within the groups (P = 0.890). Conclusion: It seems that the organization of constant-variable and self-control exercises has similar effects on the accuracy and quiet eye duration. Keywords: Quiet eye, Perceptual-cognitive skill, Motor learning, Practice organization.
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HIGHLIGHTS Rats exposed to 2.4 GHz electromagnetic fields (EMF) combined or not with physical activity and an individual physical activity group. Rats spatial learning measured by Morris water maze and motor function assessed by... more
HIGHLIGHTS Rats exposed to 2.4 GHz electromagnetic fields (EMF) combined or not with physical activity and an individual physical activity group. Rats spatial learning measured by Morris water maze and motor function assessed by Open-field EMF: electromagnetic field had adverse effect on spatial learning and decrease motor function EMF + Physical activity: Physical activity diminished undesirable effect of electromagnetic fields.
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Basal ganglia (BG) lesions cause impairments of different mammalian's movement and cognition behaviors. Motor circuit impairment has a dominant role in the movement disorders. An inhibitory factor in BG is GABA neurotransmitter, which is... more
Basal ganglia (BG) lesions cause impairments of different mammalian's movement and cognition behaviors. Motor circuit impairment has a dominant role in the movement disorders. An inhibitory factor in BG is GABA neurotransmitter, which is released from striatum. Lesions in GABAergic neurons could trigger movement and cognition disorders. Previous evidence showed that GABA B receptor agonist (Baclofen) administration in human improves movement disorders and exercise can improve neurodegenerative and cognitive decline; however, the effects of both Baclofen and mild forced treadmill exercise on movement disorders are not well known. The main objective of this study is to investigate the combined effects of mild forced treadmill exercise and microinjection of Baclofen in the internal Globus Pallidus on striatum lesioninduced impairments of spatial learning and motor activity. We used Morris water maze and open filed tests for studying spatial learning, and motor activity, respectively. Results showed that mild exercise and Baclofen microinjection could not lonely affect the spatial learning, and motor activity impairments while the combination of them could alleviate spatial learning, and motor activity impairments in striatum-lesion animals. Our results suggest that striatum lesion-induced memory and motor activity impairments can improve with combination interaction of GABA B receptor agonist and exercise training.
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Background: The external focus of attention is one of the most important and effective variables of performance and motor learning. Objectives: The current study aimed at comparing the effects of external focus of attention with... more
Background: The external focus of attention is one of the most important and effective variables of performance and motor learning. Objectives: The current study aimed at comparing the effects of external focus of attention with instructions, instructional self-talk, and augmented feedback strategies on motor learning in 10-year-old male students. Methods: Sixty students (with the mean age of 10.10 ± 0.20 years) participated in the current study voluntarily as the study samples and were randomly divided into four groups of 15 students (three experimental groups and one control group). Participants practiced overarm throwing using their non-dominant arm. In the training phase, the subjects were trained for 300 throws in five sessions (60 attempts per session) and then, they performed a retention test. One-way analysis of variance (ANOVA) was used to determine the difference between the groups. In order to investigate the intervening effects in the four groups within the pre-test, post-test, retention stages, repeated measures ANOVA and in order to determine the differences between the groups, Bonferroni post-hoc test was applied. Results: The results showed that all groups except the control group progressed in post-test and retention tests. On both tests (posttest and retention), the augmented feedback group showed the greatest throwing accuracy (P < 0.001). Also, the accuracy scores of the instructional self-talk and instruction groups were better than those of the control group (P < 0.001). Conclusions: The findings of the current study showed that the external focus of attention with the augmented feedback method was the best strategy to take advantage of the external focus of attention on motor learning in 10-year-old male students.
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Background: One of the most important goals of physical education teachers and sport trainers is to increase the amount of learning and performance of motor skills of students and athletes in the shortest time, with the lowest cost and... more
Background: One of the most important goals of physical education teachers and sport trainers is to increase the amount of learning and performance of motor skills of students and athletes in the shortest time, with the lowest cost and energy, and the highest level of motor skills learning. Therefore, teachers and sport coaches should use the best methods to learn and practice for better results. Objectives: The purpose of this study was to investigate the effect of motivational self-talk on the performance and learning of skills of throwing a tennis ball from the top of the shoulders with the use of the non-dominant hand in 10-year old male students. Methods: For this purpose, 40 male students (average age of 10. 17 ± 0.51) volunteered to participate in this study as the research sample and were randomly divided to 2 groups of 20 (motivational self-talk group and control group). In the acquisition phase, the subjects were trained continuously during 5 sessions for 5 days (6 blocks of 10 attempts per session) and on the next day, they performed a retention test with 10 attempts. To illustrate the difference between groups, independent samples t-test was used, while one-way analysis of variance was used to compare the scores of each group at each phase of study. Results: The results of the statistical methods showed that both groups improved at the acquisition stage and there was a significant difference between the groups at the acquisition stage (P < 0.001). In other words, results were in favor of the motivational self-talk group (P < 0.001). In the retention phase, there was a significant difference between the 2 groups, and this advantage was in favor of the motivational self-talk group (P < 0.001). Conclusions: In general, it is suggested for sports teachers and trainers to use motivational self-talk for improvement of various skills.
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The aim of this study was to compare the effects of errorless, error full and scaling equipment practice methods on learning of basketball free throw skill in children. 50 Boy students, 10–12 years old With a history of exercise three... more
The aim of this study was to compare the effects of errorless, error full and scaling equipment practice methods on learning of basketball free throw skill in children. 50 Boy students, 10–12 years old With a history of exercise three times a week selected and randomly divided into five groups of 10 people (Training with scaling equipment from a constant distance, Training with standard equipment from a constant distance, errorless- scaling equipment, errorless- standard equipment and error full- scaling equipment). Acquisition phase includes 5 sessions and each session was conducted 50 trials. Tests, included transfer and retention tests. Transfer test (10 throw from a distance of 3.5 meters with ball size 6 and the ring height 2.80 m) performed 10 minutes after the last trial on the last day of acquisition phase. The retention test were completed as a double transfer design with 10 throw from a distance of 3.5 meters with balls 5 and 7, with a ring height of 2.60 and 3.05 meters respectively, 24 h after the last session of Acquisition. Data was analyzed with dependent T-test, ANOVA and mixed ANOVA (at the significant level P=0.05). According to the accuracy variable, significant differences were not found between the 5 groups in retention and transfer tests. However throw pattern in groups practice with scaling equipment compared with no scaling equipment groups was better. In general, according the results of this study, it can be concluded that the use of scaling equipment training method leads to better learning of movement pattern in children.
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Background: The present study aimed to explore the effect of motor independent and dependent visual perception practices on dynamic visual acuity and depth perceptions among children aged 7-8 years. Material and Methods One hundred and... more
Background: The present study aimed to explore the effect of motor independent and dependent visual perception practices on dynamic visual acuity and depth perceptions among children aged 7-8 years. Material and Methods One hundred and seven primary school students were randomly selected through purposive sampling and divided into two experimental groups (visual perception exercises dependent vs independent to movement) and a control group. Experimental subjects were trained for six weeks and each week constituted three 45-minute sessions suited for their own planned training sessions. Analysis of Variance analysis (ANOVA) for within and between-group and Kruskal-Wallis and Wilcoxon tests were used to analyze the depth and dynamic visual acuity perception respectively. Results The results indicated that motor independent and dependent training had improved the components of depth perception and dynamic visual acuity in children aged 7-8 years, but there was no significant difference between these two training methods. Conclusion This conformed movement Pyne & Issac’s hypothesis (2005), which stated that the important issue in the development and adjustment of visual perceptual components is not an individual's movement, but selective attention to moving objects.
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The aim of this study was to determine the validity and reliability of the Persian version of Children Motor Imagery Questionnaire. For this purpose, 250 persons in the age of range 7-12 were randomly selected and then they completed the... more
The aim of this study was to determine the validity and reliability of the Persian version of Children Motor Imagery Questionnaire. For this purpose, 250 persons in the age of range 7-12 were randomly selected and then they completed the questionnaires. To determine the validity, the confirmatory factor analysis method was used. For investigating the internal consistency and temporal reliability, Cronbach's alpha coefficient and Intra-class correlation coefficient were used. Finally, in order to determine the concurrent validity, the motor imagery questionnaire-3 was utilized. Results indicate that CFI and GFI are higher than 0.9 and the RMSEA index is lower than 0.08 and also Cronbach's alpha coefficients and Intra-class correlation coefficient are α≥ 0.70. The Persian version of children motor imagery questionnaire consists of motor imagery by three-dimensional structure, internal visual imaging and external visual imaging and 12 items which support the main structure and confirms its validity in Iranian society.
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The Purpose of this study was to investigate effect of attentional focus types on health-related physical fitness factors performance in students and interaction between type of attentional focus and physical fitness level. 12 students... more
The Purpose of this study was to investigate effect of attentional focus types on health-related physical fitness factors performance in students and interaction between type of attentional focus and physical fitness level. 12 students with a high fitness level and 12 students with low physical fitness with age range of 15- 17 years were selected as sample by using purposive sampling. Subjects were performed musculoskeletal components of health-related physical fitness (sit-ups, sit-and-reach and modified pull-ups) within three day and with distance of one week between the days. In the first day attentional focus instruction was not provided. In the second and third days the subjects randomly and counterbalanced adopted internal or external focus. Data analysis with repeated measures analysis of variance and LSD post hoc was conducted.In high physical fitness group,External focus compared with internal or control cause significantly advantage in tests of sit-ups, sit-and-reach and modified pull-ups. As well as in low physical fitness, External focus compared with internal or control resulted in significantly better performance in tests of sit-and-reach and modified pull-ups (P<0.05). Internal focus compared to control resulted in significantly better performance in modified pull-ups test high physical fitness group (P<0.05). The results showed that external focus instructions is resulted in the lead performance during the assessment musculoskeletal components physical fitness related to health, regardless of the skill level. During the evaluation should also providing internal focus instruction, particularly in people with high physical fitness levels to be avoided.
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This study examined the relationship between emotional intelligence with sport Orientation of Male athletes of Confrontational fields and non_ Confrontational. the method of research is Descriptive-survey and population of the study, 200... more
This study examined the relationship between emotional intelligence with sport Orientation of Male athletes of Confrontational fields and non_ Confrontational. the method of research is Descriptive-survey and population of the study, 200 participants of Confrontational fields (handball, futsal, basketball, karate, kung fu) and non_ Confrontational (table tennis, chess, swimming, volleyball, gymnastics) of Sanandaj that was randomly selected. Participants of both emotional intelligence questionnaire of Lan et al. (2009) and McGill’s questionnaire and Dieter’s (1998) they were completed. And using Pearson’s correlation and multiple regression tests and Fisher's z at a significance level (level 05 / 0≥p) were analyzed. The result of Correlation analysis showed a significant correlation between emotional intelligence and athletic component of orientation and non-orientation is existing. Also the relationship between emotional intelligence and sport orientation in Confrontational and non_ Confrontational fields is not significant defenses. According to the results of study for achievement of Confrontational and non_ Confrontational athletes, sports equipment recommended.
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Background: One’s own motor system is activated by viewing and imaging another person performance. Purpose: The aim of this study was to investigate the motor simulation in prediction of interpersonal coordination among jumping rope elite... more
Background: One’s own motor system is activated by viewing and imaging another person performance. Purpose: The aim of this study was to investigate the motor simulation in prediction of interpersonal coordination among jumping rope elite boys. Methodology: An applied research was done as a single-stage case study with 14 jumping rope elite boys (13-18 years). The subjects practiced the jumping rope tasks (jumping rope in different distances and online landing) for four months, until they could do them properly and without any online feedbacks. This study used a Vicon motion analysis device with six infrared cameras capable of 120 frames per seconds to record three-dimensional movements of the legs and rope whirling. Results: The results of one-way ANOVA showed that with enough practice, movement onset time, hand-foot deviation time, timing variation in rope whirling, and landing time of joint groups were equal while a significant difference was observed in movement time and jump height between them (P≤0.05). Conclusion:) When people simulate a partner’s performance to do joint coordination, they may be relying on internal models that govern the interpersonal coordination. Indeed by increasing difficulty of task and so by increasing joint task demands, degree of interpersonal coordination would increase.
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The aim of this study was to compare the effects Errorless, Error full and scaling equipment methods on accuracy of the throw basketball under stress in children. 50 elementary boy students 10-12 years randomly divided into five groups... more
The aim of this study was to compare the effects Errorless, Error full and scaling equipment methods on accuracy of the throw basketball under stress in children. 50 elementary boy students 10-12 years randomly divided into five groups (errorless, error full, Training with scaling and standard equipment, scaling equipment and combined). After 5 session in acquisition, retention and transfer (under stress) tests were conducted. Revised Competitive State Anxiety Inventory-2 was filled out by participants before retention and after transfer tests. Data was analyzed with dependent t-test and mixed ANOVA. Significant reduction were found between retention and transfer tests in training with standard equipment group. Performance of standard equipment group declined under pressure. However, performance Decrement in other groups was not significant. In general, according the results of this study, the use of scaled equipment by children lead to implicit learning in the same manner as the errorless learning paradigm and prevents choking under stress. Therefore, it can be used as a proper method for teaching motor skills in children.
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The present study aimed at investigating the effect of rich environment at home on the speed of acquisition progress in football dribbling skill of boys.The statistical population included children aged between 6 and 13 in district1,... more
The present study aimed at investigating the effect of rich environment at home on the speed of acquisition progress in football dribbling skill of boys.The statistical population included children aged between 6 and 13 in district1, Tehran city. The present study was semi-experimental with pretestposttest design. Based on the results of the distributed questionnaires, 30 subjects were selected as the sample and were divided into two groups: rich and non-rich. Firstly, both groups participated in football dribbling test as the pretest. Then, both rich and non-rich groups received training for 9 days and one session per day. At the end of each training session, both groups completed football dribbling test again. To compare the groups, the 2 × 9 mixed analysis of covariance was used, and dependent t test was applied to examine intragroup changes. Wilks Lambda index indicated that the effect of environment on the speed of learning progress was significant (F(9&19)=3.27), P<0.014, correlation ratio=0.608). The rich group had a higher speed of learning progress than the non-rich group. The comparison of the training days of both groups showed that the rich group was significantly better than the non-rich group for all days except for day 4. The results of dependent t test showed a significant difference between pretest and day 9 in rich (P<0.001) and non-rich (P<0.001) groups. Overall, these results show that enriched home environment significantly improves the speed of learning progress.
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Introduction: The purpose of this study was to investigate the effect of attentional focus and frequency of feedback on performance and kinematics in basketball free throwing. Materials and Methods: In this semi-experimental research,... more
Introduction: The purpose of this study was to investigate the effect of attentional focus and frequency of feedback on performance and kinematics in basketball free throwing. Materials and Methods: In this semi-experimental research, fifty students were randomly selected using convenience sampling method, and were randomly divided in one control and 4 experimental groups (internal focus and 33% feedback, internal focus and 100% feedback, external focus and 33% feedback, and external focus and 100% feedback). Experimental groups conducted six blocks of ten attempts (every day two blocks of ten attempts) in one week, and in three sessions of training, and received internal or external focus feedback with the corresponding frequency (33% or 100%). After 72 hours, retention and transfer tests were performed with ten-attempt blocks. Performance (throwing accuracy) and kinematic data (joint angle and range of motion) were collected. Data were analyzed using ANOVA with repeated measures and one way ANOVA. Results: Feedback with external focus (100% and 33%) was more effective in improving throwing performance in retention and transfer tests (P < 0.050). Kinematic data analysis showed that external focus feedback groups had the least maximum flexion in the knee joint in retention test compare to acquisition stage (P < 0.050). Moreover, external focus groups had the least maximum flexion at the knee in retention test compared to internal focus groups (P < 0.050). In range of motion of the knee, external focus groups had more range of motion in retention and transfer tests compared to internal focus groups (P < 0.050). Conclusion: Performance improvement in external focus groups may be limited to certain changes in kinematic data, and in line with constrained-action hypothesis.
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Background: Researchers are pursuing the enhancement of sensorimotor skills through the application of virtual reality (VR) in the sports environment. Objectives: This study aimed to compare the performance and kinematics of VR with... more
Background: Researchers are pursuing the enhancement of sensorimotor skills through the application of virtual reality (VR) in the sports environment. Objectives: This study aimed to compare the performance and kinematics of VR with real-world dart-throwing. Methods: Twenty-four healthy junior high school boy students participated (aged = 13.66, SD = 0.48) in this semi-experimental study in the year of 2017. We examined mean radial and bivariate variable errors as the performance variables. The maximum flexion angle, release time angle, and angular velocity was examined as the kinematic variables. Standard dartboard, the Xbox360, the Kinect, and a high-speed camera (sampling at 240 Hz) were used to measure the performance and kinematics characteristics of upper limb motion. We used Kinovea 0.8.26 and MATLAB R2015b to analyze videos and data smoothing. One-way MANOVA was used to analyze variables. Results: The results revealed (P = 0.392) no significant differences in MRE between VR ...
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Research Interests: Art and Cinematography
High-pressure conditions have different components that are likely to have different effects on performance, which may lead to underlying mechanisms of performance decrements, such as distraction or self-focus. pressure is divided into... more
High-pressure conditions have different components that are likely to have different effects on performance, which may lead to underlying mechanisms of performance decrements, such as distraction or self-focus. pressure is divided into two categories of monitoring pressure and outcome pressure. Performing in the presence of the camera, the coach, the teammate or the spectator is called ‘monitoring pressure’. In contrast, other pressure factors, such as trying to achieve a goal, achieving a credible reward, setting a record or ranking is called ‘outcome pressure’. They acknowledged that monitoring pressure led to direct focus of attention on self or task and the outcome pressure led to distract the athlete from performing the task. A complete description of this hypothesis and the probability of decrease performance under pressure are obtained by considering the type of task. It is noted that monitoring pressure led to disruption of performing tasks that relied less on working memory (such as motor tasks) and the outcome pressure led to reduction in performance in cognitive tasks. In our study, the researchers decided to examine the different effects of pressure on different aspects of skill. For this purpose, a table tennis task was used, which includes both the motor aspect (a component in skilled athletes that relies less on working memory) and decision-making (cognitive component of skill). In addition to the environmental conditions and the ongoing task, considering a type of athlete's personality trait (reinvestment) that may lead him/her to self-focus or distraction under pressure situations can be helpful. In our study, the relationships between reinvestment and performance and decision making were measured in table tennis. This sport involves skills perform fast, and the athlete will have little opportunity to engage in the reinvestment process. . Therefore, the aim of this research was to investigate the performance and decision-making on table tennis topspin skill of elite athletes under different conditions of pressure. Forehand and backhand topspin of 20 expert table tennis athletes was examined under low, monitoring and outcome pressure. The decision making and performance scores were examined in a within-group design. Relationship between Reinvestment traits and dependent variables across low and high pressure also tested. Results showed the effects of pressure conditions on somatic and cognitive anxiety were significant. Decision-making accuracy under outcome pressure and decision-making speed under the both pressure conditions were decreased. The performance of athletes was decreased under the monitoring pressure while no change was observed in performance under outcome pressure. Decision reinvestment could predict speed accuracy changes under both pressure conditions and motor self-consciousness could predict performance changes under monitoring pressure
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Objectives This examined the effect of PETTLEP imagery on the spatial anticipation of novice soccer goalkeepers during penalty kicks. Methods Twenty-four adolescent male goalkeepers (Meanage: 14.14 ± 1.10) were selected and divided... more
Objectives This examined the effect of PETTLEP imagery on the spatial anticipation of novice soccer goalkeepers during penalty kicks. Methods Twenty-four adolescent male goalkeepers (Meanage: 14.14 ± 1.10) were selected and divided randomly into two groups. In the pretest, the goalkeepers responded to 12 video stimuli to evaluate spatial anticipation. The goalkeepers in the experimental group listened to the audio file of the PETTLEP imagery for 6 sessions where the control group was engaged in goalkeeper training only. Results Results showed the group under PETTLEP imagery intervention had a significant difference from the control group in post-test (p=0.004). Conclusions 6 sessions PETTLEP Imagery intervention has improved anticipation of novice goalkeepers during penalty kicks.
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Introduction: Children with Attention Deficit Hyperactivity Disorder, in addition to attention deficit hyperactivity disorder and alertness problems, show the the lowest level of social activity and they have more trouble finding and... more
Introduction: Children with Attention Deficit Hyperactivity Disorder, in addition to attention deficit hyperactivity disorder and alertness problems, show the the lowest level of social activity and they have more trouble finding and keeping friends. Aim: The aim of this study was to investigate the effect of motor and computer games on the attention and social communications of male students with attention deficit hyperactivity disorder aged 10-12 years. Method: The statistical population of the present study was all elementary male students aged 10-12 years with Attention Deficit / Hyperactivity Disorder in District 4 of Tehran in 2021 and 36 of them were purposefully and accessibly selected .Motor and computer games were performed in 8 weeks and in each session in 3 sessions of 60 minutes. The Connors questionnaire of the parents' version and the Zebov questionnaire were filled out by the parents in the pre-test and post-test. Repeated measure analysis and paired t-test were ...
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Background and Aim: Evaluating variability can help to investigate the process underlying motor coordination problems. The current study aimed to measure motor coordination and its variability in children with Developmental Coordination... more
Background and Aim: Evaluating variability can help to investigate the process underlying motor coordination problems. The current study aimed to measure motor coordination and its variability in children with Developmental Coordination Disorder (DCD). Moreover, the symmetry of motor coordination variability in these children and the relation between motor skills and variability were explored. Materials and Methods: After evaluating motor skills in children, aged 7-10 years using Movement Assessment Battery for Children-2 (MABC-2), 15 children with DCD and 20 non-DCD children performed a bilateral coordination task. Using motion capture system, motor coordination and variability were recorded and calculated by computing continuous relative phase and its standard deviation, respectively. Ethical Considerations: The study with an ethical code of IR.UT.SPORT.REC.1396030 was approved by Ethics Committee of Faculty of Physical Education and Sport Sciences of University of Tehran. Finding...
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Background: Although changes in performance during the learning of various sports skills have been studied, however, how these changes at the brain level is still unknown. The aim of this study was to investigate simultaneous changes in... more
Background: Although changes in performance during the learning of various sports skills have been studied, however, how these changes at the brain level is still unknown. The aim of this study was to investigate simultaneous changes in motor performance and EEG patterns in beta band during learning dart throwing skill in dominant and non-dominant hand. Methodology: The samples consisted of 14 non-athlete students with an average age of 23 ± 2.5, which were divided into two group dominant hand (7) and non-dominant hand (7). Repeated measures ANOVA were used to measure data at the execution level and changes in EEG activity. Results: The results of this study at the performance level showed a significant reduction in the absolute error of dart throwing and at the same time at the brain level increased EEG activity in frontal and parietal-posterior regions along with decreased central area activity in acquisition and retention stages in both groups (P<.05). Also, there was a significant difference between the activity of EEG pattern in the dominant and non-dominant hand groups except for two channels AF3 and PO4 (P<.05). Conclusion: In general, the results of this study showed that along with relatively constant changes in performance during dart skill learning, relatively constant changes in EEG activity pattern occur, so that the concept of motor learning is also visible at the brain level. Also, the results of this study supported the existence of the different motor program for dominant and non-dominant hand control in the conditions of bilateral transfer control.
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Reaction time (RT) is one of the psychomotor skills that determine athletes’ results and also in daily life. RT effective factors are divided into inherent (genetic) and environmental. Among those factors, psychological factors and mental... more
Reaction time (RT) is one of the psychomotor skills that determine athletes’ results and also in daily life. RT effective factors are divided into inherent (genetic) and environmental. Among those factors, psychological factors and mental abilities are more important due to the cognitive nature of RT. The aim of this research was to study the relationship between RT, anxiety and IQ of athletes in different skill levels. This relationship was investigated in 85 subjects (in elite and sub elite athletes and no athletes groups) by correlation method. To measure RT, Y1000 devise was used; Spielberger state / trait anxiety inventory (STAI) was used to evaluate anxiety and Raven’s progressive matrices to evaluate IQ. One-way analysis of variance and Pearson correlation coefficient were used to analyze the data. Results showed that there was a negative significant correlation between choice RT and IQ, and between CRT and state anxiety. Findings supported inverted U hypothesis and it proved the greater influence of IQ with higher complexity of task
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زمینه و هدف: بیماران مبتلا به اختلال شناختی خفیف از عدم کفایت در تکنیک های جبرانی و فقدان کنترل حرکتی در زمان زمین خوردن رنج می برند. هدف این تحقیق این است که آثار تمرین دوگانه پیش رونده بر عملکرد حرکتی، وضعیت شناختی و خطر زمین خوردن را... more
زمینه و هدف: بیماران مبتلا به اختلال شناختی خفیف از عدم کفایت در تکنیک های جبرانی و فقدان کنترل حرکتی در زمان زمین خوردن رنج می برند. هدف این تحقیق این است که آثار تمرین دوگانه پیش رونده بر عملکرد حرکتی، وضعیت شناختی و خطر زمین خوردن را در سالمندان ارزیابی کند. روش بررسی: این تحقیق از نوع نیمه تجربی با طرح پیش آزمون - پس آزمون بود. آزمودنی های تحقیق از بین سالمندان ساکن جامعه با روش تصادفی هدفمند انتخاب شدند و میانگین سن آنها 75.65 سال (با دامنه سنی 65 تا 90) بود. هر دو گروه تحقیق (20 نفر مبتلا به اختلال شناختی خفیف و 20 نفر سالم)، 12 هفته 3 جلسه ای تحت مداخله با تمرینات تکلیف دوگانه فزاینده قرار گرفتند. یافته ها: ارزیابیها بعد از 12 هفته نشان داد که مداخله تحقیق موجب بهبود وضعیت شناختی، کنترل قامتی و خطر زمین خوردن را در هر دو گروه دارای اختلال شناختی و وضعیت شناختی طبیعی شد. گروه اختلال شناختی تغییرات مثبت بیشتری از نظر شناخت تجربه کرد در حالی که گروه طبیعی مشهود ترین آثار را از نظر خطر زمین خوردن و عملکرد در آزمون دسترسی عملکردی داشتند. نتیجهگیری: آثار مثبت تمرینات دوگانه بر مت...
The Effect of Arousal Caused by Spectators on Process and Outcome of Volleyball Service Skill
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Imagery can be defined as the use of all the senses to recreate or construct an experience in the mind. The aim of this study was to investigate the effect of mental imagery and physical exercise on tracking task in children with... more
Imagery can be defined as the use of all the senses to recreate or construct an experience in the mind. The aim of this study was to investigate the effect of mental imagery and physical exercise on tracking task in children with developmental coordination disorder. Participants were 30 female students with developmental coordination disorder (mean age 8.22 ± 0.84) who were randomly divided into 3 groups of mental imagery, physical exercise and control group. During the study, the two groups of mental imagery and physical exercise performed their exercises for 18 sessions (17-20 minutes) and the control group performed their daily activities. At the end, all subjects performed the tracking task. The results of combined analysis of variance test 2 (time: pre-test, post-test) * 3 (group: mental imagery, physical training and control) showed experimental groups in all components of the tracking task (total time on target, Consecutive time on target, distance from target and speed) perf...
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Purpose: Mental exercise uses the same neuronal pathways involved in physical exercise to modify the pattern and function without stress caused by physical exercise. This study investigates the effect of kinesthetic imagery, active, and... more
Purpose: Mental exercise uses the same neuronal pathways involved in physical exercise to modify the pattern and function without stress caused by physical exercise. This study investigates the effect of kinesthetic imagery, active, and combined exercises (imagery and active) on the hip hyperextension and the power of selected lumbopelvic muscles in women suffering from lumbar hyperlordosis. Methods: In this quasi-experimental study, 36 women with lumbar hyperlordosis (age range: 30-40 years, non-athlete and without injury and surgery in the lumbar region) were selected and divided into three groups. The groups practiced three sessions per week for six weeks. We assessed the lumbar lordosis by a flexible ruler and the electromyographic (EMG) activity of the lumbopelvic muscles during hip hyperextension in the prone position by surface electromyogram. We also measured the power of the gluteus maximus using a dynamometer during hip hyperextension and the abdominal muscles using a goni...
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Background: The present study aimed to explore the effect of motor independent and dependent visual perception practices ondynamic visual acuityand depth perceptions among children aged 7-8 years.Materials and methods:One hundred and... more
Background: The present study aimed to explore the effect of motor independent and dependent visual perception practices ondynamic visual acuityand depth perceptions among children aged 7-8 years.Materials and methods:One hundred and seven primary school students were randomly selected through purposive sampling and divided into two experimental groups (visual perception exercises dependent vs independent to movement) and a control group. Experimental subjects were trained for 6 weeks and each week constituted three 45-minute sessions suited for their own planned training sessions. Analysis of Variance analysis (ANOVA) for within and between-group andKruskal-Wallis and Wilcoxon tests were used to analyze the depth and dynamic visual acuity perception respectively.Results:The results indicated that motor independent and dependent training had improved the components of depth perception and dynamic visual acuity in children aged 7-8 years, but there was no significant difference betwe...
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Most of the findings have focused on the importance of CD4+HLA-G+ and CD8+HLA-G+ regulatory T cells (Treg) during pregnancy. It has been demonstrated that these HLA-G+ T cell subsets could induce maternal immune tolerance against... more
Most of the findings have focused on the importance of CD4+HLA-G+ and CD8+HLA-G+ regulatory T cells (Treg) during pregnancy. It has been demonstrated that these HLA-G+ T cell subsets could induce maternal immune tolerance against semi-allogenic conceptus during pregnancy. There are only a few experiments regarding the Treg cells in the context of unexplained infertility (UI). Thirty-five participants including 18 primary unexplained infertile and 17 fertile females were enrolled in this study. A total of 3–5 ml blood samples were taken, and peripheral blood mononuclear cells (PBMCs) were separated by using Ficoll. Using a flow cytometer, the frequency of CD4+HLA-G+ and CD8+ HLA-G+ T cells was assessed in the peripheral blood samples of primary unexplained infertile and fertile females. Our results showed that the frequency of CD8+HLA-G+ Treg cells was significantly lower in primary unexplained infertile females than fertile females (P = 0.048). Although the frequency of CD4+HLA-G+ Treg cells in the primary unexplained infertile females was lower than fertile females, the difference was not statistically significant (P = 0.25). Regarding the important role of CD8+HLA-G+ Treg cells during pregnancy and its decrease in females with primary UI, it seems that reduced CD8+ HLA-G+ Treg cells could be a leading immunological factor in the context of infertility. Nevertheless, more researches are needed in this field.
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Introduction: The purpose of this study was to investigate the effect of attentional focus and frequency of feedback on performance and kinematics in basketball free throwing. Materials and Methods: In this semi-experimental research,... more
Introduction: The purpose of this study was to investigate the effect of attentional focus and frequency of feedback on performance and kinematics in basketball free throwing. Materials and Methods: In this semi-experimental research, fifty students were randomly selected using convenience sampling method, and were randomly divided in one control and 4 experimental groups (internal focus and 33% feedback, internal focus and 100% feedback, external focus and 33% feedback, and external focus and 100% feedback). Experimental groups conducted six blocks of ten attempts (every day two blocks of ten attempts) in one week, and in three sessions of training, and received internal or external focus feedback with the corresponding frequency (33% or 100%). After 72 hours, retention and transfer tests were performed with ten-attempt blocks. Performance (throwing accuracy) and kinematic data (joint angle and range of motion) were collected. Data were analyzed using ANOVA with repeated measures a...
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Introduction: Motor skill acquisition studies have shown that the performance of a motor task will be smoother after practice; however, the type of practice is very important. Thus, the aim of this study was to investigate the effect of... more
Introduction: Motor skill acquisition studies have shown that the performance of a motor task will be smoother after practice; however, the type of practice is very important. Thus, the aim of this study was to investigate the effect of practice with task-specific instability on performance and acquisition of a throwing skill. Materials and Methods: This quasi-experimental study was conducted on 16 semi-skilled subjects under 2 practice conditions, with and without availability of visual feedback. Each practice stage involved 3 blocks of 10 trials. The subjects' throwing skill was evaluated in pretest and posttests, before and after the practicing stages. Two repeated measures ANOVA and paired t-test were used to examine the differences between subjects in practicing and test stages at a significance level of 0.05. Results: No significant difference were observed between practice blocks in the two stages of practice; however, there were significant differences between pretest an...
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Introduction: The human uses vision to detect information about the task environment. Studies have shown that duration of quiet eye, motor performance, and efficiency in a number of tasks has improved using quiet eye training. The current... more
Introduction: The human uses vision to detect information about the task environment. Studies have shown that duration of quiet eye, motor performance, and efficiency in a number of tasks has improved using quiet eye training. The current study was to assess the effects of different types of quiet eye training on quiet eye and kicking skill in children with high motor proficiency. Materials and Methods: In this study, 45 boy students with high motor proficiency with age range of 7 to 10 years by performing a pretest phase, homogeneously divided in to three groups of baseline, and short-term and long-term quiet eye training. The study included pretest, acquisition, and posttest phases. In the pretest phase, the participants performed 4 soccer shots (Modified Christian Moore's Shot Test). The acquisition phase was done in 12 sessions, and 10 trials in per session. At the end of the last training session, the participants performed 4 soccer shots in the posttest phase. In each phas...
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Introduction: Quiet eye had been introduced as a period of extended gaze fixation in many targeting tasks. The aim of this study was to investigate the effect of quiet eye training with self-control and constant-variable body organization... more
Introduction: Quiet eye had been introduced as a period of extended gaze fixation in many targeting tasks. The aim of this study was to investigate the effect of quiet eye training with self-control and constant-variable body organization on performance and learning badminton low backhand service in the student novice girls. Materials and Methods: In this quasi-experimental study, 19 girl students of physical education in University of Tehran, Iran, were selected using convenience sampling method and randomly divided into two groups of self-control (n = 9) and constant-variable (n = 10). The task intention was badminton backhand low service. In order to measure the accuracy of backhand low service, we used French short serve standard five test, and to record the visual data, Ergonear Eye Tracking test was used. The day after the pretest, participants took part in 3 sections of acquisition (8 blocks with 15 trails, a total of 360 trails), and 48 hours after the acquisition test, the ...
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Abstract Introduction and Purpose: The purpose of this study was to compare the effect of self-regulation feedback with Bandwidth feedback through self-modeling strategies on volleyball service in novice and intermediate learners.... more
Abstract Introduction and Purpose: The purpose of this study was to compare the effect of self-regulation feedback with Bandwidth feedback through self-modeling strategies on volleyball service in novice and intermediate learners. Methodology:For this purpose, 22 novice and 24 intermediate learners took part in this experiment. Each group practiced volleyball tennis skills in six sessions in two sub-groups of self-regulation and Bandwidth feedback methods through self-modeling strategies. The design involved a pretest, acquisition sessions post-test, retention test in two condition (Easy and difficult) and a transfer test. In each session, the self-regulation feedback sub-group was matched to the number of feedbacks received by Bandwidth feedback subgroup; but the self-regulation feedback subgroup has a self-controlled role in when they receive feedback. Results and Conclusions: The results of repeated measure showed that both methods of providing feedback in both groups improved the performance level of the subjects in the post-test, retention test and transfer test significantly(p&lt;0.05). AlsoThe results of the t test showed that the beginners benefited from self-regulation feedback more than Bandwidth feedback in the, Difficult retention test and transfer test and they had superior motor skill learning(p&lt;0.05). while the intermediate benefited equally from self-regulation and Bandwidth feedback in transfer test (p&gt;0.05).
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The purpose of this research was to study the effect of overt and covert motivational self-talk on the performance of coincidence anticipation timing task. Participants included 36 physical education students (9 females and 27 males with... more
The purpose of this research was to study the effect of overt and covert motivational self-talk on the performance of coincidence anticipation timing task. Participants included 36 physical education students (9 females and 27 males with a mean age of 25.68±5.15 years old) right-handed and without visual impairments who participated in the research voluntarily and they assigned randomly into three groups. They performed a coincidence anticipation timing task under three conditions (overt self-talk, covert self-talk and control). Results showed that both overt and covert motivational self-talk led to improved performance in the coincidence anticipation timing and there was no significant difference between the two groups. Also significant difference was not observed in between the male and female students. According to the results of this study, the use of overt and covert motivational self-talk is a psychological strategy for improving coincidence anticipation timing task.
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The aim of the present study was to determine the validity and reliability of the Persian version of the questionnaire TOPS-2.For this purpose, 621 athletes (male: 285 and Female: 336) with skill various levels (Novice, Elite and... more
The aim of the present study was to determine the validity and reliability of the Persian version of the questionnaire TOPS-2.For this purpose, 621 athletes (male: 285 and Female: 336) with skill various levels (Novice, Elite and None-elite) in 10 team and individual sports, were selected to complete the questionnaire, randomly. The first, correctness of translation and face validity confirmed by 3 sports psychology expert and 1 English language specialist via translation-back translation method.For determining the construct validity, confirmatory factor analysis (CFA) with maximum likelihood estimation was used. Results of factor analysis showed that first model had favorable fit in practice dimension. Also, the results indicated good model fit for competition. However, a more detailed examination of the factor loadings were showed that 64 and 56 questions had values 0.11 and 0.27 respectively, and these values are lower than acceptable criteria (0.3). So, these questions were dele...
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Background: 85% of multiple sclerosis patients suffer from impaired motor function and 65% from cognitive impairment. Therefore The main purpose of this study is to improve the cognitive and motor function of patients using dual... more
Background: 85% of multiple sclerosis patients suffer from impaired motor function and 65% from cognitive impairment. Therefore The main purpose of this study is to improve the cognitive and motor function of patients using dual tasks.Methods: The study samples were 60 women with MS (20-50 years) with an Expanded Disability Status Scale 2-4 and the duration of the period (10-14 years) who were divided into 4 groups and for eight weeks each week including two sessions 45 They practiced dual cognitive, motor, and individual training for 45 to 60 minutes. Data were analyzed by composite variance analysis at significance level of P <0.05.Results: The results of compound analysis analysis showed that the training of cognitive-motor tasks improved the significance of motor function (p = 0.0005) and cognitive performance (p = 0.0001) compared to the other three groups.Conclusion: The results of this study suggest that the physical benefits of training are always superior to cognitive ch...
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The purpose of this study was to evaluate the effect of dietary zinc levels during gestation on physical development of offspring. The statistical population consisted of adult male and female rats (Albino-Wistar) which were obtained from... more
The purpose of this study was to evaluate the effect of dietary zinc levels during gestation on physical development of offspring. The statistical population consisted of adult male and female rats (Albino-Wistar) which were obtained from Pasteur Institute, Iran. After mating, 9 pregnant female rats were divided into 3 groups: 1) Zinc deficient group (0.050.05). There was a significant decrease in crown-rump length in zinc supplement as compared to control group (P&lt;0.05), but there was no significant difference in brain growth (P&gt;0.05). These findings suggest that zinc deficiency during the last three months of pregnancy impairs brain and physical growth of offspring and to impose enhanced zinc supplement during the last three months of pregnancy has negative effects on physical development.
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In Self-controlled practice, feedback is provided by the learner himself. The purpose of this study was to determine the effect of self-controlled practice of basketball shots performance on self-efficacy of female students. The... more
In Self-controlled practice, feedback is provided by the learner himself. The purpose of this study was to determine the effect of self-controlled practice of basketball shots performance on self-efficacy of female students. The statistical sample of this study included 20 female students who were randomly selected and divided into two self-controlled and yoked groups. The research was conducted in five sessions including a pre-test session, three sessions of practice, and a post-test session. Free Throw in basketball was chosen as the criterion task. The Sherer&#39;s self-efficacy questionnaire was completed and collected at the same time with pre-test and post-test. The results showed that self-controlled practice significantly contributed to the student&#39;s self-efficacy. As a result, due to the further improvement in the self-controlled group&#39;s retention and also the better self-efficacy, self-controlled practice has a positive effect on retention and self-efficacy of the individual.
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The aim of this research was to investigate the situation of talent identification process and to collect Karate related indexes in Iran. For this purpose, 63 karate subjects, male (N=31) and female (N=32), participated and filled in 3... more
The aim of this research was to investigate the situation of talent identification process and to collect Karate related indexes in Iran. For this purpose, 63 karate subjects, male (N=31) and female (N=32), participated and filled in 3 special questionnaires to identify present and optimal situation of talent identification and most important aspects of biometric, motor capabilities, psychological capacity and skill indexes. The data were analyzed by Pearson coefficient correlation (P?0.05). The results showed that although the reaction time of hand and foot, flexibility, coordination, hand and foot length, agility and sergeant jump were the most important anthropometrical factors related to successful performance, but the reaction time of hand and foot, flexibility and coordination were significant predicators of discriminating athletes. In motor capabilities, the endurance of cardiovascular system played the main role and was an important predictor. In psychological capacity, two factors of concentration and self-confidence had a critical role and only concentration was a significant predictor. The results of this study showed no pattern for talent identification in Iran from coaches and athletes’ viewpoints.
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351 تسا لوا هدنسیون یرتکد همان نایاپ زا هتفرگرب هلاقم نیا * 0 هورگ ،یرتکد یوجشناد . راتفر یتکرح و یسانشناور ،یشزرو ها شناد ،نارهت ،نارهت ناریا 1. Ph.D Student, Department of Motor Behavior and Sport Psychology, University of Tehran,... more
351 تسا لوا هدنسیون یرتکد همان نایاپ زا هتفرگرب هلاقم نیا * 0 هورگ ،یرتکد یوجشناد . راتفر یتکرح و یسانشناور ،یشزرو ها شناد ،نارهت ،نارهت ناریا 1. Ph.D Student, Department of Motor Behavior and Sport Psychology, University of Tehran, Tehran, Iran 2 ،رایشناد . ناور و یتکرح راتفر هورگ )لوئسم هدنسیون(ناریا ،نارهت ،نارهت ها شناد ،یشزرو یسانش 2. Associate Professor, Department of Motor Behavior and Sport Psychology, University of Tehran, Tehran, Iran(Corresponding Author) 3 ،رایشناد . ناور و یتکرح راتفر هورگ ناریا ،نارهت ،نارهت ها شناد ،یشزرو یسانش 3. Associate Professor, Department of Motor Behavior and Sport Psychology, University of Tehran, Tehran, Iran 4 . د ناور و یتکرح راتفر هورگ ،رایشنا ناریا ،نارهت ،نارهت ها شناد ،یشزرو یسانش . Associate Professor, Department of Motor Behavior and Sport Psychology, University of Tehran, Tehran, Iran :تفایرد 12 / 02 / 14 :ییاهن يریذپ 21 / 10 / 18 مسيناكم یسررب فلگ یيانيب لرتنك یاه یبارطضا طيارش تحت یدتبم نازاب * هنزرو یبطق دمحا 4 یزابهش یدهم ، 0 یر...
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The aim of this study was to measure the validity and reliability of perceived motivational climate in sport questionnaire (PMCSQ-2) for Newton and colleagues [2000[. For this purpose, random participants from 553 athletes 13 to 23 years... more
The aim of this study was to measure the validity and reliability of perceived motivational climate in sport questionnaire (PMCSQ-2) for Newton and colleagues [2000[. For this purpose, random participants from 553 athletes 13 to 23 years were selected to complete the questionnaire. After applying the translate-retranslate technique, content validity ratio (CVR) and content validity index (CVI) confirmed by 10 Panels (CVR=0.66, CVI=0.97.For determining the construct validity, confirmatory factor analysis (CFA) based on structural equations was used, internal consistency of questionnaire was achieved by Cranach&#39;s alpha and Pearson correlation coefficient under test-retest method to study reliability of questionnaire. Results showed that the first model of PMCSQ-2(33 question (, wasn’t able to support the favorable fit and thus eliminated 6 problematic questions. Thereby the final model with 27 questions was included task-oriented climate (TOC) (effort/improvement, important role and cooperative learning) and ego-oriented climate (EOC) (unequal recognition and punishment of mistakes). Hereby, the Persian PMCSQ-2 (PPMCSQ-2) had acceptable fit index (RMSEA= 0.054, CFI= 0.9). Also, Internal consistency was acceptable (TOC=0.827, EOC=0.726 and PPMCSQ-2=0.618) and reliability of PPMCSQ-2(r=0.73) was affirmed. Therefore, PPMCSQ-2 can be used as a valid and reliable instrument to assess motivational climate in the Iranian athletes with the age range of 13 to 23 years.
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Purpose: Expertise in sport relies on interactions between individual, task and environment constraints. Individual performer constraints include mental and physical characteristics. The present study aimed to measure the functional... more
Purpose: Expertise in sport relies on interactions between individual, task and environment constraints. Individual performer constraints include mental and physical characteristics. The present study aimed to measure the functional capacities and mental skills in adolescent, elite (N=26) and sub-elite (N=35) soccer players to determine the important factors in the talent selection process. Material and Methods: Participants were classified in four groups according to their age: U16, U15, U14 and U13. The OMSAT-3 was used to evaluate the mental skills. Furthermore, functional capacities were measured using four tests including aerobic resistance (shuttle run), explosive power (vertical jump), running speed (running with the ball) and strength (shooting). Results: The results of the present study showed a significant difference between elite and sub-elite soccer players in three functional and seven mental characteristics. There were significant differences between elite and sub-elite soccer players regarding functional capacities between U15 and U16 players. Also, mental skills differentiated between elite and sub-elite players in U13, U14 and U16 age groups. Discussion and Conclusion: It seems that soccer players lacking functional capacities and mental skills may not continue the participation and/or may not be selected for higher level participations. These results suggest that performance and psychometric characteristics of young soccer players differ at different ages. According to the results it seems that mental skill measurements at ages under 13 and 14 can help the selection process, but functional capacities should be emphasized at U15 and U16 age groups.
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The aim of this study was to compare the effects Errorless, Error full and scaling equipment methods on accuracy of the throw basketball under stress in children. 50 elementary boy students 10-12 years randomly divided into five groups... more
The aim of this study was to compare the effects Errorless, Error full and scaling equipment methods on accuracy of the throw basketball under stress in children. 50 elementary boy students 10-12 years randomly divided into five groups (errorless, error full, Training with scaling and standard equipment, scaling equipment and combined). After 5 session in acquisition, retention and transfer (under stress) tests were conducted. Revised Competitive State Anxiety Inventory-2 was filled out by participants before retention and after transfer tests. Data was analyzed with dependent t-test and mixed ANOVA. Significant reduction were found between retention and transfer tests in training with standard equipment group. Performance of standard equipment group declined under pressure. However, performance Decrement in other groups was not significant. In general, according the results of this study, the use of scaled equipment by children lead to implicit learning in the same manner as the er...
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Introduction: Acquisition of a skill is affected by constraints. Therefore, the purpose of this study was to investigate the effect of task constraints manipulation on motor skill learning in children. Materials and Methods: This... more
Introduction: Acquisition of a skill is affected by constraints. Therefore, the purpose of this study was to investigate the effect of task constraints manipulation on motor skill learning in children. Materials and Methods: This quasi-experimental study with a pretest-posttest design was conducted on 20 primary school children of 10-12 years of age. The subjects were selected through convenience sampling and randomly divided into two groups (training with scaled equipment and standard equipment). Acquisition phase included 5 sessions and each session consisted of 50 trials. Tests were performed with ball sizes of 5, 6, and 7 and ring height of 2.60 m, 2.80 m, and 3.05 m, respectively. Transfer test was performed 10 minutes after the last trial on the last day of acquisition phase using a size 6 ball. The retention test was conducted 24 hours after the last session of acquisition. Data were analyzed using mixed-design ANOVA, and paired and independent t-test at the significance leve...
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The mechanism and neural origin of the differences between the two hands in motor control and learning are still unknown. The aim of the present research is to examine the changes in synergy patterns in different brain regions while... more
The mechanism and neural origin of the differences between the two hands in motor control and learning are still unknown. The aim of the present research is to examine the changes in synergy patterns in different brain regions while learning the dart throwing skill with the dominant and non-dominant hand. The sample population consisted of 10 students aged 23±2.5 divided into two groups of dominant and non-dominant hand. To record brain activities, a 32-channel wireless Electro-encephalography (EEG) system was used. Data were recorded through three stages of pre-test (pre-training), acquisition (after 4 weeks of training) and retention (after one week of non-training). EEG signals were analysed in alpha, beta and gamma bands. EEG analysis showed that the synergy patterns during acquisition and retention stages were significantly similar to each other and largely different from the pre-training stage in all three bands. Increasing activity levels of the contralateral cortical areas a...