Vastus Lateralis

Research Paper: Comparing Electromyographic Activity of Quadriceps Muscle During Straight Leg Raise in Individuals With and Without Patellofemoral Pain Syndrome Purpose: This study aimed to investigate the electromyographic activities and balance of Vastus Medialis Obliquus (VMO) and Vastus Lateralis (VL) muscles during Straight Leg Raise (SLR) in individuals with and without Patellofemoral Pain Syndrome (PFPS). Methods: Through an analytical case-control study, 26 persons with PFPS and 26 healthy subjects were recruited by non-random and convenience sampling method. All subjects performed SLR movement. The EMG activity of VMO, VL and VMO/VL ratio were recorded and measured. The muscles activation level were compared between the 2 groups using the Independent t test. The obtained data were analyzed using SPSS. Results: The mean and maximum EMG activity of VMO, VL and VMO/VL ratio did not have any significant differences between the PFPS and healthy groups (P>0.05). In other words, during SLR, the VMO and VL muscles activation in the PFPS group were approximately the same as the healthy group. Citation Lotfi H, Nodehi Moghadam A, Shati M. Comparing Electromyographic Activity of Quadriceps Muscle During Straight Leg Raise in Individuals With and Without Patellofemoral Pain Syndrome. Physical Treatments. 2018; 7(4):197-204.

Scrotum reconstruction is challenging. Both the functional and cosmetic outcome are considered. Many reconstructive methods have been described, from burying the exposed testicles into a subcutaneous pocket to local musculocutaneous or fasciocutaneous flaps. We report our experience of treating three patients for scrotal reconstruction by using the anterolateral thigh island flap. Three patients received scrotum reconstruction with the anterolateral thigh island flap from 2003 to 2007. Two of them had Fournier’s gangrene and one had hidradenitis suppurativa. In two occasions a “true” perforator flap was used and in one a small muscle cuff of the vastus lateralis muscle was also included. All three flaps were successful. One patient had a proximal donor site wound dehiscence due to inadequate drainage. Simple conservative treatment resolved the problem. No patient had any functional donor site morbidity. We conclude that the anterolateral thigh flap is a valuable tool in reconstructi...

The muscles of the hip, high and leg region of the goats were studied under conditions of explotation semi intensive with technical histochemical, with the purpose of knowing the percentage distribution of the different types of fibers, that which contributes to the characterization of the normal muscle, indispensable condition for the later study of the pathology, the genetic one and possibly to determine some organoleptics characteristic of the meat. They took samples in alive of the muscles Biceps femoris, Middle gluteal, Deep gluteal, Vastus intermedius, Vastus lateralis, Gastrocnemius, Soleus, Semimembronosus, Semitendinosus and Tensor fasciae latae, in five (5) goats of 21-30 Kg. of weight. The samples froze in isopentano cooled in liquid nitrogen. The cuts were carried out in a cryostat to -20°C, with a thickness of 10 µm. They were carried out the reactions of the Adenosine Trifosfatase (ATP-handle) with a pH of preincubation 4.33 and 4.37 to determine the percentage distrib...

Despite the functional importance of the human quadriceps femoris in movements such as running, jumping, lifting and climbing, and the known effects of muscle architecture on muscle function, no research has fully described the complex architecture of this muscle group. ...

The influence of training on GLUT4 expression in slow- and fast-twitch skeletal muscle fibres was studied in male endurance-trained athletes and control subjects. The trained state was ensured by elevated maximal oxygen uptake (29%), as well as citrate synthase (60%) and 3-hydroxy-acyl-CoA dehydrogenase (38%) activities in muscle biopsy samples of the vastus lateralis. GLUT4 densities in slow- and fast-twitch fibres were measured by the use of a newly developed, sensitive method combining immunohistochemistry with morphometry, and no effect of training was found. GLUT4 density was higher in slow-twitch fibres compared to fast-twitch fibres (P<0.05) when biopsy samples from untrained subjects were examined. In athletes GLUT4 density was identical in slow- and fast-twitch fibres. Slow-twitch fibre diameters were 10% larger in the athletes (P<0.01), and slow-twitch fibre fractions were 140% of the fraction in the control group. Thus, GLUT4 originating from slow-twitch fibres was increased by 30% (P<0.02) in athletes. We conclude that long-lasting endurance training increases slow-twitch fibre GLUT4 expression by means of an elevated slow-twitch fibre mass in human skeletal muscle.

The aim of this study was to find out if it is possible to predict the height of the vertical jump from kinematic, dynamometric and anthropometric variables using a multiple linear regression model. Fifty-three subjects, 21 male and 9 female volleyball players of first National categories (First National League and First League), as well as 23 Physical Education students (12 males and 11 females) participated in this study. First, the height of the flight during the performance of a "squat jump" (SJ) and "countermovement jump" (CMJ) was determined. Then, the maximal isometric strength in the squat position was assessed with the knees bent at 90o, 120o and 140o while the electromyographic activity was simultaneously recorded on the vastus lateralis with surface electrodes. The muscle mass of the lower limbs was obtained by dual-energy X-ray absorptiometry (DEXA). The positive mechanical impulse explained on its own 77% of jumping height variability. Prediction pow...

Stroke disability is attributed to upper motor neuron deficits resulting from ischemic brain injury. We have developed proteome maps of the Vastus lateralis to examine the effects of ischemic brain injury on paretic skeletal muscle myofilament proteins. Proteomics analyses from seven hemiparetic stroke patients have detected a decrease of three troponin T isoforms in the paretic muscle suggesting that myosin–actin interactions may be attenuated. We propose that ischemic brain injury may prevent troponin T participation in complex formation thereby affecting the protein interactions associated with excitation–contraction coupling. We have also detected a novel skeletal troponin T isoform that has a C-terminal variation. Our data suggest that the decreased slow troponin T isoform pools in the paretic limb may contribute to the gait deficit after stroke. The complexity of the neurological deficit on Vastus lateralis is suggested by the multiple changes in proteins detected by our proteomics mapping.

In order to study the effects of increasing age on the human skeletal muscle, cross-sections (15 μm) of autopsied whole vastus lateralis muscle from 43 previously physically healthy men between 15 and 83 years of age were prepared and examined. The data obtained on ...

Quantitative telemetered electromyography from the four heads of the quadriceps femoris (vastus medialis, rectus femoris, vastus intermedius and vastus lateralis) during normal postures and locomotion (quadrupedal resting, walk/run, gallop and leaping) is presented for the brown lemur, Lemur fulvus. The vastus intermedius is the sole contributor to muscle recruitment during quadrupedal resting postures. It exhibits consistently high levels of electrical activity during all locomotory behaviour. The vastus medialis is recruited least among these muscles during walk/run and tends to be 'saved' for galloping and leaping. The rectus femoris and vastus lateralis are recruited at similarly high levels during all phasic activities. The rectus femoris appears to be used eccentrically, storing 'elastic strain energy' during all phasic activities. The vastus lateralis combines exceptionally high potential effective force with relatively high potential velocity and resistance t...

The vinculin-talin-integrin system and the dystrophin-glycoprotein complex (DGC) are two protein systems with structural and signaling functions, allowing interaction between muscle fibers and extracellular matrix. Although numerous studies have been conducted on these systems, their localization and distribution patterns along the nonjunctional sarcolemma are not clear. On this basis, we carried out an indirect immunofluorescence study on the vastus lateralis muscle of human adults not affected by neuromuscular diseases to better define these patterns. Our results showed that all tested proteins of the two systems have a costameric distribution; all tested proteins of the two systems colocalize with each other (about 90-95% of the cases); only alpha-sarcoglycan in a few cases (about 6%) does not colocalize with other proteins; in about 9-10% of the cases, dystrophin and beta-dystroglycan colocalize partially with other proteins; all tested proteins can be localized in different fibers, both in the region of the sarcolemma over I or A bands. The colocalization between the vinculin-talin-integrin and DGC systems may imply their functional interaction involving the structural aspect, by providing a stronger adhesion between sarcolemma and extracellular matrix in well-defined regions of the muscle fiber. Besides, their colocalization may suggest the existence of a mechanism of mutual modulation of the transmitted signals. This reciprocal control may determine, in different conditions, the prevalence of one system over another with a consequent transmission of different messages to the sarcolemma-associated cytoskeleton.

The echogenicity patterns of ultrasound scans contain information of tissue composition in muscles. The aim was: (1) to develop a quantitative ultrasound image analysis to characterize tissue composition in terms of intensity and structure of the ultrasound images, and (2) to use the method for characterization of ultrasound images of the supraspinatus muscle, and the vastus lateralis muscle. Computerized texture analyses employing first-order and higher-order grey-scale statistics were developed to objectively characterize ultrasound images of m. supraspinatus and m. vastus lateralis from 9 healthy participants. The mean grey-scale intensity was higher in the vastus lateralis muscle (p < 0.05) than in the supraspinatus muscle (average value of middle measuring site 51.4 compared to 35.0). Furthermore, the number of spatially connected and homogeneous regions (blobs) was higher in the vastus lateralis (p < 0.05) than in the supraspinatus (average for m. vastus lateralis: 0.092...

The aim of this study was to find out if it is possible to predict the height of the vertical jump from kinematic, dynamometric and anthropometric variables using a multiple linear regression model. Fifty-three subjects, 21 male and 9 female volleyball players of first National categories (First National League and First League), as well as 23 Physical Education students (12 males and 11 females) participated in this study. First, the height of the flight during the performance of a "squat jump" (SJ) and "countermovement jump" (CMJ) was determined. Then, the maximal isometric strength in the squat position was assessed with the knees bent at 90º, 120º and 140º while the electromyographic activity was simultaneously recorded on the vastus lateralis with surface electrodes. The muscle mass of the lower limbs was obtained by dual-energy X- ray absorptiometry (DEXA). The positive mechanical impulse explained on its own 77% of jumping height variability. Prediction po...

The impact of ageing on force and velocity of human skeletal muscle fibres has been extensively studied. As discrepancies have been reported, it is still unclear whether or not a deterioration of the capacity of muscle fibres to develop force and shortening is involved in determining weakness and decrease in shortening velocity of skeletal muscle of elderly people. We compared myosin heavy chain (MHC) isoform distribution of vastus lateralis muscle, and specific force (Po/CSA) and maximum shortening velocity (Vo) of skeletal muscle fibres among one population of young controls (CTRL) and three populations of elderly (EL) subjects with very variable levels of physical activity: sedentary (EL-SED, n = 3); controls (EL-CTRL, n = 4); endurance trained (EL-END, n = 3). Muscle phenotype was progressively faster in the order EL-END --> CTRL --> EL-CTRL --> EL-SED. Po/CSA and Vo also varied among the different populations of elderly subjects generally showing a decreasing deterioration with increasing activity levels. The results suggest that discrepancies observed so far in age-induced deterioration of contractile properties of muscle fibres could depend on the different activity levels of the populations of elderly subjects enrolled in the studies.

ABSTRACT Introduction. – The aim of this study was to analyse the evolution of neuromuscular fatigue in vastus lateralis and gastrocnemius medialis muscles during all-out cycling test at 100% maximal aerobic power.Fact synthesis. – Mean EMG increased from the beginning of the test and then decreased after have attained its maximum for all subjects and for both muscles, whereas the EMG burst duration remained constant.Conclusion. – The decrease of muscular activity towards the end of the test, whereas the intensity remains constant, seems to indicate synergist muscles activation, i.e. a mechanism of adaptation underlying the fatigue process.

The purpose of the study was to examine the adaptive changes in myosin heavy chain (MHC) and light chain (MLC) isoforms in human vastus lateralis muscle caused by long-term strength and power training (54 weeks, approximately 3 times a week) in untrained middle-aged men (16 in the training and 6 in the control group). Muscular MHC and MLC isoforms were determined by means of SDS-PAGE gel electrophoresis. During the training period, maximal anaerobic cycling power increased by 64 W (p < 0.001) and the maximal jumping height by 1.5 cm (p < 0.05) in the training group, but no significant changes were found in the control group. However, the group by time effect was not significant. In the training group, the increase of the maximal jumping height correlated with the number of strength and power training sessions (r = 0.56; p < 0.05). The change of the proportion of MHC IIa isoform from 52.6 ± 12.2 % to 59.4 ± 11.6 % did not reach statistical significance (p = 0.070 for group b...