Different exercises are prescribed by physiotherapists and despite the popular use of elastic res... more Different exercises are prescribed by physiotherapists and despite the popular use of elastic resistance, few studies have investigated the effect of such rehabilitation tools on shoulder resultant net moment (RNM). The aim of the present study was to compare shoulder RNM peak values and the respective angle of occurrence during three shoulder rehabilitation exercises: 1) elevation in the scapular plane; 2) flexion; and 3) abduction when performed in three different load situations: 1) without external load; 2) with dumbbells (DB); and 3) with elastic resistance. Twenty-one healthy subjects participated in the study. Kinematic data were obtained by means of an inverse dynamic model. A two-way ANOVA was used for data analysis (α < 0.05). The highest RNM peak for abductor and external rotator muscles was during shoulder abduction exercise and for flexor muscles was during flexion and elevation in the scapular plane. The DB load condition was associated with highest RNM peak values for all muscle groups. This study presents differences among three exercises and load situations for RNM peak values and angle of occurrence. Furthermore, it also presents theoretical rationale for load progress and selection of exercises for shoulder rehabilitation management. Clinicians should consider it, when prescribing strengthening exercises for shoulder rehabilitation.
Joint kinematic assessment using an electromagnetic tracking device (EMTD) requires palpation-dig... more Joint kinematic assessment using an electromagnetic tracking device (EMTD) requires palpation-digitization (PD) of bony landmarks to define the anatomical axes. Errors in PD of bony landmarks can perturb the anatomical axes and affect the validity and reliability of kinematic measurements. The validity and reliability of PD for kinematic measurement needs to be explored before recommending its wider use. A systematic search of 15 electronic databases located studies assessing validity and/or reliability of PD for joint kinematic assessment. Two independent reviewers used the QUADAS and QAREL tools to assess quality of validity and reliability studies respectively. The results were synthesized qualitatively using a level of evidence approach. Eight studies satisfied the final eligibility criteria and were included in the review. The validity, intra-rater reliability and inter-rater reliability were assessed in three, seven and one study respectively. The overall level of evidence for validity of PD technique was strong with high correlation (≥0.80) reported by three high (≥60%) quality studies. The overall level of evidence for intra-rater reliability was also strong with very high ICC (≥0.90) and satisfactory SEM (SEM% ≤ 10%) reported by four high quality studies. However the level of evidence for inter-rater reliability was limited and needs to be addressed by future research.
The aim of this study was to compare shoulder muscle force and moment production during external ... more The aim of this study was to compare shoulder muscle force and moment production during external rotation performed in the transverse and sagittal planes. An optimization model was used for estimating shoulder muscle force production of infraspinatus, teres minor, supraspinatus, anterior deltoid, middle deltoid and posterior deltoid muscles. The model uses as input data the external rotation moment, muscle moment arm magnitude, muscle physiologic cross-sectional area and muscle specific tension. The external rotation moment data was gathered from eight subjects in transverse and six subjects in sagittal plane using an isokinetic dynamometer. In the sagittal plane, all studied muscles presented larger estimated force in comparison to the transverse plane. The infraspinatus, teres minor, supraspinatus and posterior deltoid muscles presented larger moment in sagittal when compared to transverse plane. When prescribing shoulder rehabilitation exercises, therapists should bear in mind the described changes in muscle force production.
Corresponding author at: Department of Physical Therapy, East Tennessee State University, PO Box ... more Corresponding author at: Department of Physical Therapy, East Tennessee State University, PO Box 70624, Johnson City, TN 37614, USA. Tel.: +1 423 439 8295. ... No abstract is available. To read the body of this article, please view the Full Text online.
The primary aim of this study is to determine whether a combination of body height, terrain and v... more The primary aim of this study is to determine whether a combination of body height, terrain and vehicle mechanical factors confound for the effect of body mass on WBV exposure while using a quad bike under normal rural working conditions. A seat pad mounted triaxial accelerometer and data logger recorded full work day vibration and shock data from 130 New Zealand rural workers. Personal, vehicle and workplace characteristics were gathered using a modified version of the Whole Body Vibration Health Surveillance Questionnaire. Whole-body vibrations were analysed in accordance with the ISO 2631-1 and ISO 2631-5 standards and it is presented as one hour vibration dose value in the Z-direction (1 h VDVZ). Body mass did not demonstrate any significant bivariate association (P > 0.20) with 1 h VDVZ. However BMI, body height, vehicle weight, sheep farm, dairy farm, 2 shock absorber solid axle rear suspension, flat farmland and engine capacity (cc) all demonstrated threshold bivariate associations (P _ 0.20) with 1 h VDVZ. Body mass, body height, 2 shock absorber solid rear axle suspension, and working on a sheep farm created the strongest multiple regression model explaining 16% of variance in VDVZ. Relevance to industry: The influence of driver’s body mass on vibration exposure is strongly influenced by work environment and vehicle mechanical factors and this should be taken in to consideration for research that explores exposures and/or designing seating and suspension systems to attenuate vibration exposures in small on-farm vehicles.
OBJECTIVES:
To assess the evidence for a dose-response relationship between ROM, duration, and f... more OBJECTIVES:
To assess the evidence for a dose-response relationship between ROM, duration, and frequency of trunk flexion, and risk of occupational LBP. METHODS:
An electronic systematic search was conducted using Medline, Cumulative Index to Nursing and Allied Health Literature, EMBASE, and Scopus databases focusing on cohort and case-control studies. Studies were included if they focused on non-specific LBP and postural exposure, considering ROM, duration, or frequency of trunk flexion as independent variables. No language restriction was imposed. Included studies were assessed for risk of bias using the Newcastle-Ottawa Scale for observational studies and a summary of evidence is presented. RESULTS:
Eight studies were included and all were methodologically rated as high quality. The included studies yielded a total of 7023 subjects who were considered for risk analysis. Different outcome measures for postural exposure were adopted making meta-analysis difficult to perform. CONCLUSIONS:
We could not find a clear dose-response relationship for work posture exposures and LBP. Limited evidence was found for ROM and duration of sustained flexed posture as risk factor for LBP. We found no evidence for frequency of trunk flexion as a risk factor for LBP.
Purpose
The present systematic review assessed the level of evidence for the association betwee... more Purpose
The present systematic review assessed the level of evidence for the association between relaxin levels and pregnancy-related pelvic girdle pain (PPGP) during pregnancy.
Methods
PRISMA guidelines were followed to conduct this systematic review. Electronic search was carried out using six different databases. Observational cohorts, cross-sectional or case–control studies focused on the association between relaxin levels and PPGP during pregnancy were included. Studies selection was conducted by two reviewers who screened firstly for titles, then for abstracts and finally for full articles. Risk of bias was assessed using the Newcastle–Ottawa scale and the quality of evidence by the guidelines proposed by the Cochrane back review group.
Results
731 references were identified. Six articles met the inclusion criteria and were considered for this systematic review. The main reason for the studies exclusion was PPGP related to gynaecological reasons. Five studies were case–control and one study was a prospective cohort. Four studies were ranked as high while two were ranked as low quality. Among the high quality studies, three found no association between PPGP and relaxin levels.
Conclusions
Based on these findings, the level of evidence for the association between PPGP and relaxin levels was found to be low. PPGP assessment and controlling for risk factors were found to increase bias leaving uncertainty in interpretation of these findings and a need for further research.
The aim of the present study was to examine the within-day reliability of the Spineangel® postura... more The aim of the present study was to examine the within-day reliability of the Spineangel® postural monitoring device and to measure cumulative lumbo-pelvic posture exposure of health care workers. Twenty-one workers from an aged-care residential home wore the Spineangel, attached to the belt or waistband of their normal work apparel, during a period of the work shift. To assess the within-day reliability of measurements, 11 workers performed two sets of three lumbo-pelvic forward flexion, sustaining them for five 5 s each, at the beginning and at the end of the work shift. Different thresholds for cumulative postural exposure were measured. The reliability was found to be excellent (ICC = 0.81). On average, a threshold of 30° of lumbo-pelvic forward flexion was exceeded 1069 times/h (SD 2157.1); at 45°, 121 times/h (SD 223.8); and at 60°, 8 times/h (SD 21.8). The use of Spineangel isthus likely to be a useful device for monitoring work posture.
Statement of Relevance: The Spineangel® is capable of providing reliable postural measurements in the workplace. Different cumulative postural exposure thresholds were established considering three domains of cumulative exposure: magnitude (range of motion), frequency and duration. The implementation of such domains for cumulative exposure allowed us to explore interesting forms of monitoring posture exposure.
The patellofemoral pain syndrome (PFPS) is a common disorder of the knee; it’s often caused by an... more The patellofemoral pain syndrome (PFPS) is a common disorder of the knee; it’s often caused by an excessive lateral traction of the patella. Subjects with this syndrome usually present a disruption in the activation of Vastus Mediallis Obliquus (VMO), which provides the patellar medial pull. Non-operative treatment includes quadriceps strengthening in order to promote better patellar stability and traction. Many researchers have been trying to selectively recruit the VMO, in order to improve treatments. The main purpose of this study is to investigate, using electromyography, the interference of angular speed and different ways of fixing the elastic tube on the quadriceps activity. Ten male subjects without any kind of muscle or joint injury participated in this study. Subjects with a Q angle value out of 10-15° were excluded from this study. The elastic tube was fixed parallel and oblique to the subjects’ body. Knee extensions were performed at 60°/sec and 120°/sec. No selective activity of the VMO was found. By comparing the levels of muscular activity, there was an increase of the electromyographic activity level in all portions of the quadriceps at the two angular speeds, only for parallel-fixed elastic tubes. These results suggest a synergic activity between VMO and the other portions of the quadriceps.
The effect of an accelerometer driven electronic postural monitor (Spineangel®) placed within the... more The effect of an accelerometer driven electronic postural monitor (Spineangel®) placed within the electromagnetic measurement field of the Polhemus Fastrak™ is unknown. This study assessed the reliability and accuracy of Fastrak™ linear and angular measurements, when the Spineangel® was placed close to the sensor(s) and transmitter. Bland Altman plots and intraclass correlation coefficient (2,1) were used to determine protocol reproducibility and measurement consistency. Excellent reliability was found for linear and angular measurements (0.96, 95% CI: 0.90-0.99; and 1.00, 95% CI: 1.00-1.00, respectively) with the inclusion of Spineangel®; similar results were found, without the inclusion of Spineangel®, for linear and angular measurements, (0.96, 95% CI: 0.89-0.99; and 1.00, 95% CI: 1.00-1.00, respectively). The greatest linear discrepancies between the two test conditions were found to be less than 3.5 mm, while the greatest angular discrepancies were below 3.5°. As the effect on accuracy was minimal, these findings support the conjoint use of the Fastrak™ during validation studies of the Spineangel® device. Statement of Relevance: Although previous studies have used the Fastrak™ as the gold standard measurement system, the influence of an accelerometer driven postural monitor on accuracy has not been reported. The strength of the present study has been to determine the effect of accelerometer placement within the electromagnetic field on the reliability and accuracy of the Fastrak™.
3D model for analysis of resultant proximal
reaction forces and moments for the upper limb
Ob... more 3D model for analysis of resultant proximal
reaction forces and moments for the upper limb
Objectives: The aim of this study was to implement a biomechanical model, with linked segments associated with inverse dynamics, to analyze proximal net forces and moments during different upper limbs’ activities. Methods: one male subject performed flexion, extension and abduction of the shoulder and flexion of the elbow. The model is composed
of five connected rigid segments (hand, forearm, arm, scapula and trunk). The Newton-Euler motion equations were used to quantify proximal net reaction forces and moments. For kinematics recording, five cameras with a frequency sample of 50 fps were used. Videogrammetry accuracy was, on average, 1,7mm. The following muscles had their activities monitored: deltoid (anterior, medial, posterior), biceps brachialis, triceps brachialis, pectoralis major. The model was evaluated by qualitative comparison of proximal net moments with electromyographic signal of agonist muscles. Results: The results showed a temporal synchronism between the proximal net moments and agonist EMG activity. Conclusions: The model was able to estimate proximal net
forces and moments during different upper limbs’ activities.
Link segment models are extremely useful for increasing the comprehension of joint overload. The ... more Link segment models are extremely useful for increasing the comprehension of joint overload. The aim of the present study was to analyze proximal joint reaction forces and moments during different movements performed with and without external load. One subject performed shoulder flexion, extension and abduction, and elbow flexion movements
(with and without external load) Kinematic data were obtained
by videogrammetry (frequency sample 50 fields/s). One link segment model was used to obtain kinetic data. The model is governed by Newton/Euler movement equations. The results suggested a not proportional increasing of proximal joint reaction forces and moments. The proximal joint reaction force longitudinal component was the only one that increased proportionally to the external load. Proximal joint reaction force shearing components and proximal moments presented
increasing values of different magnitudes. The use of external load promoted increased magnitudes of proximal joint reaction force and moment, although it was not proportional. Proximal joint reaction force and moment are influenced in different ways by the external load. This suggests the need of a strict control of the prescribed exercises for different shoulder dysfunctions.
Several studies have investigated different injuries that occur among soccer players. However, it... more Several studies have investigated different injuries that occur among soccer players. However, it has been noticed that none has mentioned injury to the external obturator muscle. As a small and monoarticulated muscle, its incidence is probably low and barely documented in the literature. Therefore, the aim of this study is to present four external obturator muscle strain cases in a professional soccer team in 2008. The data was collected from a database using the software Sistema de Preparação Desportiva which provides data such as name, diagnosis, trauma mechanism, clinical history, time away from training and progress. All athletes who undertook Magnetic Resonance Imaging (MRI) of the external obturator muscle and presented rupture of the external obturator muscle were included in the study. Four external obturator muscle strain injuries were identified from a total of twenty-eight muscle strains during the year of 2006. All athletes presented diffuse pain on the hip for medial and lateral rotation of the joint. The predominant injury mechanism was lateral rotation of the trunk over the femur on closed kinetic chain. It was concluded that external obturator muscle strain injuries can be mistaken for those related to the hip adductor muscles due to the reported pain area. Clinical examination should be based on the athletes’ report and functional tests, mainly for the hip rotator muscles. The MRI scan was essential to the location, classification and evaluation of the injury size.
In joints with 3 degrees of freedom, such as the shoulder joint, the association of different mov... more In joints with 3 degrees of freedom, such as the shoulder joint, the association of different movements results in changes in the behavior of the moment arm of the muscles. The capacity of torque production for the same movement can be changed when movements take place in a different plane. The objective of this study is to quantify differences between torque production and resultant force estimated during the shoulder external rotation in two movement planes: the transverse and sagittal planes (with 90 degrees of shoulder abduction). Eight individuals were evaluated using an isokinetic dynamometer and an eletrogoniometer for movements in the transverse plane and six individuals for movements in the sagittal plane. The results showed that the execution of the external rotation in the sagittal plane allowed greater torque magnitudes and resultant force compared with those in the transverse plane, probably owing to a prestretching of infraspinatus and teres minor.
Shoulder injuries are often related to rotator cuff muscles. Although there are various models fo... more Shoulder injuries are often related to rotator cuff muscles. Although there are various models for muscle force estimation, it is difficult to ensure that the results obtained with such models are reliable. The aim of the current study was to compare two models of muscle force estimation. Eight subjects, seven male and one female (mean age of 24 yr; mean height of 1.83 m), performed five isokinetic maximum concentric contractions of internal and external shoulder rotation. Two models with different algorithms were used. In both, the input data consisted of the measured internal rotation moment. Comparisons were made between the difference and the average results obtained with each model of muscle force estimation. There was reasonable agreement among the results for force between the two models for subscapularis, pectoralis major, and anterior deltoideus muscles results. Conversely, poor correlation was found for the latissimus dorsi, teres major, and middle deltoid. These results suggest that the algorithm structure might have a strong effect on muscle force estimation results.
OBJECTIVE:
To offer a three-dimensional description of the scapular kinematics and scapulohumeral... more OBJECTIVE: To offer a three-dimensional description of the scapular kinematics and scapulohumeral rhythm (SHR) in healthy subjects during quasi-static shoulder abduction. To analyze and compare the influence of loaded and unloaded conditions on scapula kinematics and SHR. DESIGN: Eleven subjects were analyzed using videogrammetry and the application of mathematical modelling during quasi-static shoulder abduction positions (intervals of approximately 30 degrees). MAIN OUTCOME MEASUREMENTS: Scapular kinematic data under unloaded and loaded conditions. RESULTS: The scapula presented external rotation, upward rotation and posterior tilting during the studied movement. Analyzing the scapulohumeral rhythm, different behaviours were observed in the scapular movement planes. Loading condition increased scapular upward rotation and posterior tilt at 60 degrees and 90 degrees of abduction (p>0.01). CONCLUSIONS: Analyzed scapular kinematics and scapulohumeral rhythm showed differences between adopted loading conditions. The clinical applications of these findings are discussed.
Link segment models are usually used to calculate proximal net reaction forces (PRF), as well as,... more Link segment models are usually used to calculate proximal net reaction forces (PRF), as well as, proximal net moments (PNM). The correlation between electromyographic data and PNM is usually used to verify the model's results. Nevertheless, this method permits only a qualitative verification of the obtained results. To assess model's results in a quantitative perspective, another approach is needed. The aim of the current study was to assess the propagation of uncertainty on a link segment model results and identify the main sources of error on the quantification of PRF and PNM. One male performed five repetitions of different upper limb movements. An inverse dynamics approach associate with 3D link segment model was used to quantify PRF and PNM. The results of the model were evaluated by the use of Kleine and McClintock's equation. The propagation of uncertainty for PRF reached, on average, 0.27 and for PNM, 0.97. The main cause of propagation of uncertainty was associated to the second time derivative calculations. Consequently, it is possible to suggest that the reduction of small distortions of center of mass acceleration will diminish the proximal net moment and proximal reaction force uncertainty values.
Effective intervention for low back pain (LBP) can include feedback in one form or other. Althoug... more Effective intervention for low back pain (LBP) can include feedback in one form or other. Although extrinsic feedback (EF) can be provided in a number of ways, most research has not considered how different EF characteristics (e.g. timing and content) influence treatment outcomes. A systematic search related to feedback and LBP was performed on relevant electronic databases. This narrative review aims to describe the forms of feedback provision in the literature regarding management of LBP, and to discuss these in light of previously recommended principles for the use of extrinsic feedback. The present review found support for the provision of EF that focuses on content characteristics including program feedback, summary results feedback, and external focus of attention. Temporal characteristics should enhance the use of intermittent or self-selected feedback. The literature does not support the provision of concurrent or constant EF. As much of the literature related to EF in the management of LBP has not considered content and timing characteristics we have identified future research directions that will clarify the use of content and timing characteristics of EF relative to the management of LBP.
Low back pain (LBP) is associated with dysfunction of global and local muscle systems, feedback a... more Low back pain (LBP) is associated with dysfunction of global and local muscle systems, feedback and feedforward postural control mechanisms. Physiotherapists include the use of feedback as part of treatment protocols. Such feedback can focus on a variety of neuromuscular impairments, although the literature related to feedback on the management of LBP has focused mainly on local muscle system impairments. Furthermore, there are various characteristics of feedback that can lead to motor control enhancement or deterioration. The aim of this manuscript is to present a rationale for feedback provision as a rehabilitation tool on the management of LBP. Feedback provision should focus on the main neuromuscular impairment presented by the patient. The suggested rationale describes decision-making stages for the use and progress of feedback interventions. Local muscle system impairment might benefit more from parameter feedback provision, while global muscle system and feedback mechanism impairments may benefit better from program feedback. The described rationale has the potential to help clinicians select the appropriate feedback for the treatment of their patients. Additionally, the presented rationale could be used by researchers to assess how different forms of feedback provision impact on clinical outcomes.
Different exercises are prescribed by physiotherapists and despite the popular use of elastic res... more Different exercises are prescribed by physiotherapists and despite the popular use of elastic resistance, few studies have investigated the effect of such rehabilitation tools on shoulder resultant net moment (RNM). The aim of the present study was to compare shoulder RNM peak values and the respective angle of occurrence during three shoulder rehabilitation exercises: 1) elevation in the scapular plane; 2) flexion; and 3) abduction when performed in three different load situations: 1) without external load; 2) with dumbbells (DB); and 3) with elastic resistance. Twenty-one healthy subjects participated in the study. Kinematic data were obtained by means of an inverse dynamic model. A two-way ANOVA was used for data analysis (α < 0.05). The highest RNM peak for abductor and external rotator muscles was during shoulder abduction exercise and for flexor muscles was during flexion and elevation in the scapular plane. The DB load condition was associated with highest RNM peak values for all muscle groups. This study presents differences among three exercises and load situations for RNM peak values and angle of occurrence. Furthermore, it also presents theoretical rationale for load progress and selection of exercises for shoulder rehabilitation management. Clinicians should consider it, when prescribing strengthening exercises for shoulder rehabilitation.
Joint kinematic assessment using an electromagnetic tracking device (EMTD) requires palpation-dig... more Joint kinematic assessment using an electromagnetic tracking device (EMTD) requires palpation-digitization (PD) of bony landmarks to define the anatomical axes. Errors in PD of bony landmarks can perturb the anatomical axes and affect the validity and reliability of kinematic measurements. The validity and reliability of PD for kinematic measurement needs to be explored before recommending its wider use. A systematic search of 15 electronic databases located studies assessing validity and/or reliability of PD for joint kinematic assessment. Two independent reviewers used the QUADAS and QAREL tools to assess quality of validity and reliability studies respectively. The results were synthesized qualitatively using a level of evidence approach. Eight studies satisfied the final eligibility criteria and were included in the review. The validity, intra-rater reliability and inter-rater reliability were assessed in three, seven and one study respectively. The overall level of evidence for validity of PD technique was strong with high correlation (≥0.80) reported by three high (≥60%) quality studies. The overall level of evidence for intra-rater reliability was also strong with very high ICC (≥0.90) and satisfactory SEM (SEM% ≤ 10%) reported by four high quality studies. However the level of evidence for inter-rater reliability was limited and needs to be addressed by future research.
The aim of this study was to compare shoulder muscle force and moment production during external ... more The aim of this study was to compare shoulder muscle force and moment production during external rotation performed in the transverse and sagittal planes. An optimization model was used for estimating shoulder muscle force production of infraspinatus, teres minor, supraspinatus, anterior deltoid, middle deltoid and posterior deltoid muscles. The model uses as input data the external rotation moment, muscle moment arm magnitude, muscle physiologic cross-sectional area and muscle specific tension. The external rotation moment data was gathered from eight subjects in transverse and six subjects in sagittal plane using an isokinetic dynamometer. In the sagittal plane, all studied muscles presented larger estimated force in comparison to the transverse plane. The infraspinatus, teres minor, supraspinatus and posterior deltoid muscles presented larger moment in sagittal when compared to transverse plane. When prescribing shoulder rehabilitation exercises, therapists should bear in mind the described changes in muscle force production.
Corresponding author at: Department of Physical Therapy, East Tennessee State University, PO Box ... more Corresponding author at: Department of Physical Therapy, East Tennessee State University, PO Box 70624, Johnson City, TN 37614, USA. Tel.: +1 423 439 8295. ... No abstract is available. To read the body of this article, please view the Full Text online.
The primary aim of this study is to determine whether a combination of body height, terrain and v... more The primary aim of this study is to determine whether a combination of body height, terrain and vehicle mechanical factors confound for the effect of body mass on WBV exposure while using a quad bike under normal rural working conditions. A seat pad mounted triaxial accelerometer and data logger recorded full work day vibration and shock data from 130 New Zealand rural workers. Personal, vehicle and workplace characteristics were gathered using a modified version of the Whole Body Vibration Health Surveillance Questionnaire. Whole-body vibrations were analysed in accordance with the ISO 2631-1 and ISO 2631-5 standards and it is presented as one hour vibration dose value in the Z-direction (1 h VDVZ). Body mass did not demonstrate any significant bivariate association (P > 0.20) with 1 h VDVZ. However BMI, body height, vehicle weight, sheep farm, dairy farm, 2 shock absorber solid axle rear suspension, flat farmland and engine capacity (cc) all demonstrated threshold bivariate associations (P _ 0.20) with 1 h VDVZ. Body mass, body height, 2 shock absorber solid rear axle suspension, and working on a sheep farm created the strongest multiple regression model explaining 16% of variance in VDVZ. Relevance to industry: The influence of driver’s body mass on vibration exposure is strongly influenced by work environment and vehicle mechanical factors and this should be taken in to consideration for research that explores exposures and/or designing seating and suspension systems to attenuate vibration exposures in small on-farm vehicles.
OBJECTIVES:
To assess the evidence for a dose-response relationship between ROM, duration, and f... more OBJECTIVES:
To assess the evidence for a dose-response relationship between ROM, duration, and frequency of trunk flexion, and risk of occupational LBP. METHODS:
An electronic systematic search was conducted using Medline, Cumulative Index to Nursing and Allied Health Literature, EMBASE, and Scopus databases focusing on cohort and case-control studies. Studies were included if they focused on non-specific LBP and postural exposure, considering ROM, duration, or frequency of trunk flexion as independent variables. No language restriction was imposed. Included studies were assessed for risk of bias using the Newcastle-Ottawa Scale for observational studies and a summary of evidence is presented. RESULTS:
Eight studies were included and all were methodologically rated as high quality. The included studies yielded a total of 7023 subjects who were considered for risk analysis. Different outcome measures for postural exposure were adopted making meta-analysis difficult to perform. CONCLUSIONS:
We could not find a clear dose-response relationship for work posture exposures and LBP. Limited evidence was found for ROM and duration of sustained flexed posture as risk factor for LBP. We found no evidence for frequency of trunk flexion as a risk factor for LBP.
Purpose
The present systematic review assessed the level of evidence for the association betwee... more Purpose
The present systematic review assessed the level of evidence for the association between relaxin levels and pregnancy-related pelvic girdle pain (PPGP) during pregnancy.
Methods
PRISMA guidelines were followed to conduct this systematic review. Electronic search was carried out using six different databases. Observational cohorts, cross-sectional or case–control studies focused on the association between relaxin levels and PPGP during pregnancy were included. Studies selection was conducted by two reviewers who screened firstly for titles, then for abstracts and finally for full articles. Risk of bias was assessed using the Newcastle–Ottawa scale and the quality of evidence by the guidelines proposed by the Cochrane back review group.
Results
731 references were identified. Six articles met the inclusion criteria and were considered for this systematic review. The main reason for the studies exclusion was PPGP related to gynaecological reasons. Five studies were case–control and one study was a prospective cohort. Four studies were ranked as high while two were ranked as low quality. Among the high quality studies, three found no association between PPGP and relaxin levels.
Conclusions
Based on these findings, the level of evidence for the association between PPGP and relaxin levels was found to be low. PPGP assessment and controlling for risk factors were found to increase bias leaving uncertainty in interpretation of these findings and a need for further research.
The aim of the present study was to examine the within-day reliability of the Spineangel® postura... more The aim of the present study was to examine the within-day reliability of the Spineangel® postural monitoring device and to measure cumulative lumbo-pelvic posture exposure of health care workers. Twenty-one workers from an aged-care residential home wore the Spineangel, attached to the belt or waistband of their normal work apparel, during a period of the work shift. To assess the within-day reliability of measurements, 11 workers performed two sets of three lumbo-pelvic forward flexion, sustaining them for five 5 s each, at the beginning and at the end of the work shift. Different thresholds for cumulative postural exposure were measured. The reliability was found to be excellent (ICC = 0.81). On average, a threshold of 30° of lumbo-pelvic forward flexion was exceeded 1069 times/h (SD 2157.1); at 45°, 121 times/h (SD 223.8); and at 60°, 8 times/h (SD 21.8). The use of Spineangel isthus likely to be a useful device for monitoring work posture.
Statement of Relevance: The Spineangel® is capable of providing reliable postural measurements in the workplace. Different cumulative postural exposure thresholds were established considering three domains of cumulative exposure: magnitude (range of motion), frequency and duration. The implementation of such domains for cumulative exposure allowed us to explore interesting forms of monitoring posture exposure.
The patellofemoral pain syndrome (PFPS) is a common disorder of the knee; it’s often caused by an... more The patellofemoral pain syndrome (PFPS) is a common disorder of the knee; it’s often caused by an excessive lateral traction of the patella. Subjects with this syndrome usually present a disruption in the activation of Vastus Mediallis Obliquus (VMO), which provides the patellar medial pull. Non-operative treatment includes quadriceps strengthening in order to promote better patellar stability and traction. Many researchers have been trying to selectively recruit the VMO, in order to improve treatments. The main purpose of this study is to investigate, using electromyography, the interference of angular speed and different ways of fixing the elastic tube on the quadriceps activity. Ten male subjects without any kind of muscle or joint injury participated in this study. Subjects with a Q angle value out of 10-15° were excluded from this study. The elastic tube was fixed parallel and oblique to the subjects’ body. Knee extensions were performed at 60°/sec and 120°/sec. No selective activity of the VMO was found. By comparing the levels of muscular activity, there was an increase of the electromyographic activity level in all portions of the quadriceps at the two angular speeds, only for parallel-fixed elastic tubes. These results suggest a synergic activity between VMO and the other portions of the quadriceps.
The effect of an accelerometer driven electronic postural monitor (Spineangel®) placed within the... more The effect of an accelerometer driven electronic postural monitor (Spineangel®) placed within the electromagnetic measurement field of the Polhemus Fastrak™ is unknown. This study assessed the reliability and accuracy of Fastrak™ linear and angular measurements, when the Spineangel® was placed close to the sensor(s) and transmitter. Bland Altman plots and intraclass correlation coefficient (2,1) were used to determine protocol reproducibility and measurement consistency. Excellent reliability was found for linear and angular measurements (0.96, 95% CI: 0.90-0.99; and 1.00, 95% CI: 1.00-1.00, respectively) with the inclusion of Spineangel®; similar results were found, without the inclusion of Spineangel®, for linear and angular measurements, (0.96, 95% CI: 0.89-0.99; and 1.00, 95% CI: 1.00-1.00, respectively). The greatest linear discrepancies between the two test conditions were found to be less than 3.5 mm, while the greatest angular discrepancies were below 3.5°. As the effect on accuracy was minimal, these findings support the conjoint use of the Fastrak™ during validation studies of the Spineangel® device. Statement of Relevance: Although previous studies have used the Fastrak™ as the gold standard measurement system, the influence of an accelerometer driven postural monitor on accuracy has not been reported. The strength of the present study has been to determine the effect of accelerometer placement within the electromagnetic field on the reliability and accuracy of the Fastrak™.
3D model for analysis of resultant proximal
reaction forces and moments for the upper limb
Ob... more 3D model for analysis of resultant proximal
reaction forces and moments for the upper limb
Objectives: The aim of this study was to implement a biomechanical model, with linked segments associated with inverse dynamics, to analyze proximal net forces and moments during different upper limbs’ activities. Methods: one male subject performed flexion, extension and abduction of the shoulder and flexion of the elbow. The model is composed
of five connected rigid segments (hand, forearm, arm, scapula and trunk). The Newton-Euler motion equations were used to quantify proximal net reaction forces and moments. For kinematics recording, five cameras with a frequency sample of 50 fps were used. Videogrammetry accuracy was, on average, 1,7mm. The following muscles had their activities monitored: deltoid (anterior, medial, posterior), biceps brachialis, triceps brachialis, pectoralis major. The model was evaluated by qualitative comparison of proximal net moments with electromyographic signal of agonist muscles. Results: The results showed a temporal synchronism between the proximal net moments and agonist EMG activity. Conclusions: The model was able to estimate proximal net
forces and moments during different upper limbs’ activities.
Link segment models are extremely useful for increasing the comprehension of joint overload. The ... more Link segment models are extremely useful for increasing the comprehension of joint overload. The aim of the present study was to analyze proximal joint reaction forces and moments during different movements performed with and without external load. One subject performed shoulder flexion, extension and abduction, and elbow flexion movements
(with and without external load) Kinematic data were obtained
by videogrammetry (frequency sample 50 fields/s). One link segment model was used to obtain kinetic data. The model is governed by Newton/Euler movement equations. The results suggested a not proportional increasing of proximal joint reaction forces and moments. The proximal joint reaction force longitudinal component was the only one that increased proportionally to the external load. Proximal joint reaction force shearing components and proximal moments presented
increasing values of different magnitudes. The use of external load promoted increased magnitudes of proximal joint reaction force and moment, although it was not proportional. Proximal joint reaction force and moment are influenced in different ways by the external load. This suggests the need of a strict control of the prescribed exercises for different shoulder dysfunctions.
Several studies have investigated different injuries that occur among soccer players. However, it... more Several studies have investigated different injuries that occur among soccer players. However, it has been noticed that none has mentioned injury to the external obturator muscle. As a small and monoarticulated muscle, its incidence is probably low and barely documented in the literature. Therefore, the aim of this study is to present four external obturator muscle strain cases in a professional soccer team in 2008. The data was collected from a database using the software Sistema de Preparação Desportiva which provides data such as name, diagnosis, trauma mechanism, clinical history, time away from training and progress. All athletes who undertook Magnetic Resonance Imaging (MRI) of the external obturator muscle and presented rupture of the external obturator muscle were included in the study. Four external obturator muscle strain injuries were identified from a total of twenty-eight muscle strains during the year of 2006. All athletes presented diffuse pain on the hip for medial and lateral rotation of the joint. The predominant injury mechanism was lateral rotation of the trunk over the femur on closed kinetic chain. It was concluded that external obturator muscle strain injuries can be mistaken for those related to the hip adductor muscles due to the reported pain area. Clinical examination should be based on the athletes’ report and functional tests, mainly for the hip rotator muscles. The MRI scan was essential to the location, classification and evaluation of the injury size.
In joints with 3 degrees of freedom, such as the shoulder joint, the association of different mov... more In joints with 3 degrees of freedom, such as the shoulder joint, the association of different movements results in changes in the behavior of the moment arm of the muscles. The capacity of torque production for the same movement can be changed when movements take place in a different plane. The objective of this study is to quantify differences between torque production and resultant force estimated during the shoulder external rotation in two movement planes: the transverse and sagittal planes (with 90 degrees of shoulder abduction). Eight individuals were evaluated using an isokinetic dynamometer and an eletrogoniometer for movements in the transverse plane and six individuals for movements in the sagittal plane. The results showed that the execution of the external rotation in the sagittal plane allowed greater torque magnitudes and resultant force compared with those in the transverse plane, probably owing to a prestretching of infraspinatus and teres minor.
Shoulder injuries are often related to rotator cuff muscles. Although there are various models fo... more Shoulder injuries are often related to rotator cuff muscles. Although there are various models for muscle force estimation, it is difficult to ensure that the results obtained with such models are reliable. The aim of the current study was to compare two models of muscle force estimation. Eight subjects, seven male and one female (mean age of 24 yr; mean height of 1.83 m), performed five isokinetic maximum concentric contractions of internal and external shoulder rotation. Two models with different algorithms were used. In both, the input data consisted of the measured internal rotation moment. Comparisons were made between the difference and the average results obtained with each model of muscle force estimation. There was reasonable agreement among the results for force between the two models for subscapularis, pectoralis major, and anterior deltoideus muscles results. Conversely, poor correlation was found for the latissimus dorsi, teres major, and middle deltoid. These results suggest that the algorithm structure might have a strong effect on muscle force estimation results.
OBJECTIVE:
To offer a three-dimensional description of the scapular kinematics and scapulohumeral... more OBJECTIVE: To offer a three-dimensional description of the scapular kinematics and scapulohumeral rhythm (SHR) in healthy subjects during quasi-static shoulder abduction. To analyze and compare the influence of loaded and unloaded conditions on scapula kinematics and SHR. DESIGN: Eleven subjects were analyzed using videogrammetry and the application of mathematical modelling during quasi-static shoulder abduction positions (intervals of approximately 30 degrees). MAIN OUTCOME MEASUREMENTS: Scapular kinematic data under unloaded and loaded conditions. RESULTS: The scapula presented external rotation, upward rotation and posterior tilting during the studied movement. Analyzing the scapulohumeral rhythm, different behaviours were observed in the scapular movement planes. Loading condition increased scapular upward rotation and posterior tilt at 60 degrees and 90 degrees of abduction (p>0.01). CONCLUSIONS: Analyzed scapular kinematics and scapulohumeral rhythm showed differences between adopted loading conditions. The clinical applications of these findings are discussed.
Link segment models are usually used to calculate proximal net reaction forces (PRF), as well as,... more Link segment models are usually used to calculate proximal net reaction forces (PRF), as well as, proximal net moments (PNM). The correlation between electromyographic data and PNM is usually used to verify the model's results. Nevertheless, this method permits only a qualitative verification of the obtained results. To assess model's results in a quantitative perspective, another approach is needed. The aim of the current study was to assess the propagation of uncertainty on a link segment model results and identify the main sources of error on the quantification of PRF and PNM. One male performed five repetitions of different upper limb movements. An inverse dynamics approach associate with 3D link segment model was used to quantify PRF and PNM. The results of the model were evaluated by the use of Kleine and McClintock's equation. The propagation of uncertainty for PRF reached, on average, 0.27 and for PNM, 0.97. The main cause of propagation of uncertainty was associated to the second time derivative calculations. Consequently, it is possible to suggest that the reduction of small distortions of center of mass acceleration will diminish the proximal net moment and proximal reaction force uncertainty values.
Effective intervention for low back pain (LBP) can include feedback in one form or other. Althoug... more Effective intervention for low back pain (LBP) can include feedback in one form or other. Although extrinsic feedback (EF) can be provided in a number of ways, most research has not considered how different EF characteristics (e.g. timing and content) influence treatment outcomes. A systematic search related to feedback and LBP was performed on relevant electronic databases. This narrative review aims to describe the forms of feedback provision in the literature regarding management of LBP, and to discuss these in light of previously recommended principles for the use of extrinsic feedback. The present review found support for the provision of EF that focuses on content characteristics including program feedback, summary results feedback, and external focus of attention. Temporal characteristics should enhance the use of intermittent or self-selected feedback. The literature does not support the provision of concurrent or constant EF. As much of the literature related to EF in the management of LBP has not considered content and timing characteristics we have identified future research directions that will clarify the use of content and timing characteristics of EF relative to the management of LBP.
Low back pain (LBP) is associated with dysfunction of global and local muscle systems, feedback a... more Low back pain (LBP) is associated with dysfunction of global and local muscle systems, feedback and feedforward postural control mechanisms. Physiotherapists include the use of feedback as part of treatment protocols. Such feedback can focus on a variety of neuromuscular impairments, although the literature related to feedback on the management of LBP has focused mainly on local muscle system impairments. Furthermore, there are various characteristics of feedback that can lead to motor control enhancement or deterioration. The aim of this manuscript is to present a rationale for feedback provision as a rehabilitation tool on the management of LBP. Feedback provision should focus on the main neuromuscular impairment presented by the patient. The suggested rationale describes decision-making stages for the use and progress of feedback interventions. Local muscle system impairment might benefit more from parameter feedback provision, while global muscle system and feedback mechanism impairments may benefit better from program feedback. The described rationale has the potential to help clinicians select the appropriate feedback for the treatment of their patients. Additionally, the presented rationale could be used by researchers to assess how different forms of feedback provision impact on clinical outcomes.
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Papers by Daniel Ribeiro
To assess the evidence for a dose-response relationship between ROM, duration, and frequency of trunk flexion, and risk of occupational LBP.
METHODS:
An electronic systematic search was conducted using Medline, Cumulative Index to Nursing and Allied Health Literature, EMBASE, and Scopus databases focusing on cohort and case-control studies. Studies were included if they focused on non-specific LBP and postural exposure, considering ROM, duration, or frequency of trunk flexion as independent variables. No language restriction was imposed. Included studies were assessed for risk of bias using the Newcastle-Ottawa Scale for observational studies and a summary of evidence is presented.
RESULTS:
Eight studies were included and all were methodologically rated as high quality. The included studies yielded a total of 7023 subjects who were considered for risk analysis. Different outcome measures for postural exposure were adopted making meta-analysis difficult to perform.
CONCLUSIONS:
We could not find a clear dose-response relationship for work posture exposures and LBP. Limited evidence was found for ROM and duration of sustained flexed posture as risk factor for LBP. We found no evidence for frequency of trunk flexion as a risk factor for LBP.
The present systematic review assessed the level of evidence for the association between relaxin levels and pregnancy-related pelvic girdle pain (PPGP) during pregnancy.
Methods
PRISMA guidelines were followed to conduct this systematic review. Electronic search was carried out using six different databases. Observational cohorts, cross-sectional or case–control studies focused on the association between relaxin levels and PPGP during pregnancy were included. Studies selection was conducted by two reviewers who screened firstly for titles, then for abstracts and finally for full articles. Risk of bias was assessed using the Newcastle–Ottawa scale and the quality of evidence by the guidelines proposed by the Cochrane back review group.
Results
731 references were identified. Six articles met the inclusion criteria and were considered for this systematic review. The main reason for the studies exclusion was PPGP related to gynaecological reasons. Five studies were case–control and one study was a prospective cohort. Four studies were ranked as high while two were ranked as low quality. Among the high quality studies, three found no association between PPGP and relaxin levels.
Conclusions
Based on these findings, the level of evidence for the association between PPGP and relaxin levels was found to be low. PPGP assessment and controlling for risk factors were found to increase bias leaving uncertainty in interpretation of these findings and a need for further research.
Statement of Relevance: The Spineangel® is capable of providing reliable postural measurements in the workplace. Different cumulative postural exposure thresholds were established considering three domains of cumulative exposure: magnitude (range of motion), frequency and duration. The implementation of such domains for cumulative exposure allowed us to explore interesting forms of monitoring posture exposure.
reaction forces and moments for the upper limb
Objectives: The aim of this study was to implement a biomechanical model, with linked segments associated with inverse dynamics, to analyze proximal net forces and moments during different upper limbs’ activities. Methods: one male subject performed flexion, extension and abduction of the shoulder and flexion of the elbow. The model is composed
of five connected rigid segments (hand, forearm, arm, scapula and trunk). The Newton-Euler motion equations were used to quantify proximal net reaction forces and moments. For kinematics recording, five cameras with a frequency sample of 50 fps were used. Videogrammetry accuracy was, on average, 1,7mm. The following muscles had their activities monitored: deltoid (anterior, medial, posterior), biceps brachialis, triceps brachialis, pectoralis major. The model was evaluated by qualitative comparison of proximal net moments with electromyographic signal of agonist muscles. Results: The results showed a temporal synchronism between the proximal net moments and agonist EMG activity. Conclusions: The model was able to estimate proximal net
forces and moments during different upper limbs’ activities.
(with and without external load) Kinematic data were obtained
by videogrammetry (frequency sample 50 fields/s). One link segment model was used to obtain kinetic data. The model is governed by Newton/Euler movement equations. The results suggested a not proportional increasing of proximal joint reaction forces and moments. The proximal joint reaction force longitudinal component was the only one that increased proportionally to the external load. Proximal joint reaction force shearing components and proximal moments presented
increasing values of different magnitudes. The use of external load promoted increased magnitudes of proximal joint reaction force and moment, although it was not proportional. Proximal joint reaction force and moment are influenced in different ways by the external load. This suggests the need of a strict control of the prescribed exercises for different shoulder dysfunctions.
identified from a total of twenty-eight muscle strains during the year of 2006. All athletes presented diffuse pain on the hip for medial and lateral rotation of the joint. The predominant injury mechanism was lateral rotation of the trunk over the femur on closed kinetic chain. It was concluded that external obturator muscle strain injuries can be mistaken for those related to the hip adductor muscles due to the reported pain area. Clinical
examination should be based on the athletes’ report and functional tests, mainly for the hip rotator muscles. The MRI scan was essential to the location, classification and evaluation of the injury size.
To offer a three-dimensional description of the scapular kinematics and scapulohumeral rhythm (SHR) in healthy subjects during quasi-static shoulder abduction. To analyze and compare the influence of loaded and unloaded conditions on scapula kinematics and SHR.
DESIGN:
Eleven subjects were analyzed using videogrammetry and the application of mathematical modelling during quasi-static shoulder abduction positions (intervals of approximately 30 degrees).
MAIN OUTCOME MEASUREMENTS:
Scapular kinematic data under unloaded and loaded conditions.
RESULTS:
The scapula presented external rotation, upward rotation and posterior tilting during the studied movement. Analyzing the scapulohumeral rhythm, different behaviours were observed in the scapular movement planes. Loading condition increased scapular upward rotation and posterior tilt at 60 degrees and 90 degrees of abduction (p>0.01).
CONCLUSIONS:
Analyzed scapular kinematics and scapulohumeral rhythm showed differences between adopted loading conditions. The clinical applications of these findings are discussed.
To assess the evidence for a dose-response relationship between ROM, duration, and frequency of trunk flexion, and risk of occupational LBP.
METHODS:
An electronic systematic search was conducted using Medline, Cumulative Index to Nursing and Allied Health Literature, EMBASE, and Scopus databases focusing on cohort and case-control studies. Studies were included if they focused on non-specific LBP and postural exposure, considering ROM, duration, or frequency of trunk flexion as independent variables. No language restriction was imposed. Included studies were assessed for risk of bias using the Newcastle-Ottawa Scale for observational studies and a summary of evidence is presented.
RESULTS:
Eight studies were included and all were methodologically rated as high quality. The included studies yielded a total of 7023 subjects who were considered for risk analysis. Different outcome measures for postural exposure were adopted making meta-analysis difficult to perform.
CONCLUSIONS:
We could not find a clear dose-response relationship for work posture exposures and LBP. Limited evidence was found for ROM and duration of sustained flexed posture as risk factor for LBP. We found no evidence for frequency of trunk flexion as a risk factor for LBP.
The present systematic review assessed the level of evidence for the association between relaxin levels and pregnancy-related pelvic girdle pain (PPGP) during pregnancy.
Methods
PRISMA guidelines were followed to conduct this systematic review. Electronic search was carried out using six different databases. Observational cohorts, cross-sectional or case–control studies focused on the association between relaxin levels and PPGP during pregnancy were included. Studies selection was conducted by two reviewers who screened firstly for titles, then for abstracts and finally for full articles. Risk of bias was assessed using the Newcastle–Ottawa scale and the quality of evidence by the guidelines proposed by the Cochrane back review group.
Results
731 references were identified. Six articles met the inclusion criteria and were considered for this systematic review. The main reason for the studies exclusion was PPGP related to gynaecological reasons. Five studies were case–control and one study was a prospective cohort. Four studies were ranked as high while two were ranked as low quality. Among the high quality studies, three found no association between PPGP and relaxin levels.
Conclusions
Based on these findings, the level of evidence for the association between PPGP and relaxin levels was found to be low. PPGP assessment and controlling for risk factors were found to increase bias leaving uncertainty in interpretation of these findings and a need for further research.
Statement of Relevance: The Spineangel® is capable of providing reliable postural measurements in the workplace. Different cumulative postural exposure thresholds were established considering three domains of cumulative exposure: magnitude (range of motion), frequency and duration. The implementation of such domains for cumulative exposure allowed us to explore interesting forms of monitoring posture exposure.
reaction forces and moments for the upper limb
Objectives: The aim of this study was to implement a biomechanical model, with linked segments associated with inverse dynamics, to analyze proximal net forces and moments during different upper limbs’ activities. Methods: one male subject performed flexion, extension and abduction of the shoulder and flexion of the elbow. The model is composed
of five connected rigid segments (hand, forearm, arm, scapula and trunk). The Newton-Euler motion equations were used to quantify proximal net reaction forces and moments. For kinematics recording, five cameras with a frequency sample of 50 fps were used. Videogrammetry accuracy was, on average, 1,7mm. The following muscles had their activities monitored: deltoid (anterior, medial, posterior), biceps brachialis, triceps brachialis, pectoralis major. The model was evaluated by qualitative comparison of proximal net moments with electromyographic signal of agonist muscles. Results: The results showed a temporal synchronism between the proximal net moments and agonist EMG activity. Conclusions: The model was able to estimate proximal net
forces and moments during different upper limbs’ activities.
(with and without external load) Kinematic data were obtained
by videogrammetry (frequency sample 50 fields/s). One link segment model was used to obtain kinetic data. The model is governed by Newton/Euler movement equations. The results suggested a not proportional increasing of proximal joint reaction forces and moments. The proximal joint reaction force longitudinal component was the only one that increased proportionally to the external load. Proximal joint reaction force shearing components and proximal moments presented
increasing values of different magnitudes. The use of external load promoted increased magnitudes of proximal joint reaction force and moment, although it was not proportional. Proximal joint reaction force and moment are influenced in different ways by the external load. This suggests the need of a strict control of the prescribed exercises for different shoulder dysfunctions.
identified from a total of twenty-eight muscle strains during the year of 2006. All athletes presented diffuse pain on the hip for medial and lateral rotation of the joint. The predominant injury mechanism was lateral rotation of the trunk over the femur on closed kinetic chain. It was concluded that external obturator muscle strain injuries can be mistaken for those related to the hip adductor muscles due to the reported pain area. Clinical
examination should be based on the athletes’ report and functional tests, mainly for the hip rotator muscles. The MRI scan was essential to the location, classification and evaluation of the injury size.
To offer a three-dimensional description of the scapular kinematics and scapulohumeral rhythm (SHR) in healthy subjects during quasi-static shoulder abduction. To analyze and compare the influence of loaded and unloaded conditions on scapula kinematics and SHR.
DESIGN:
Eleven subjects were analyzed using videogrammetry and the application of mathematical modelling during quasi-static shoulder abduction positions (intervals of approximately 30 degrees).
MAIN OUTCOME MEASUREMENTS:
Scapular kinematic data under unloaded and loaded conditions.
RESULTS:
The scapula presented external rotation, upward rotation and posterior tilting during the studied movement. Analyzing the scapulohumeral rhythm, different behaviours were observed in the scapular movement planes. Loading condition increased scapular upward rotation and posterior tilt at 60 degrees and 90 degrees of abduction (p>0.01).
CONCLUSIONS:
Analyzed scapular kinematics and scapulohumeral rhythm showed differences between adopted loading conditions. The clinical applications of these findings are discussed.