A Study to Assess Electromyographic Activity of Vastus Medialis Oblique and Vastus Lateralis During Semisquat With Different Hip Positions in Normal Healthy Individuals

Abstract

Background:The knee complex is the most often injured joints in human body. Performing functional tasks like getting up from the bench, unipedal jumping and rising on the heels may favour patella lateralization and predispose towards developing patellofemoral disorders. It has been hypothesized that an imbalance between the vastus medialis oblique (VMO) and the vastus lateralis (VL) muscles, may be an etiological factor in the development of patellofemoral pain syndrome. The squat is one of the most frequently used Exercises to strengthen VMO for strengthening and conditioning in many sports routines designed to enhance athletic performance.Purpose Of Study: To determine the VMO muscles activity and VMO/VL ratio with 30 degree of squat in different hip position.Methods: 250 normal healthy individual, with age ranging from 18-25 years, who fulfilled the inclusion and exclusion criteria, were recruited in the study. MVIC was recorded for vastus medialis obliqus and vastus lateralis form both knees with 30 degree squat position. Three position of hip (Neutral hip position, 45º medial rotation of hip and 30º lateral rotation of hip) were performed in both lower limb and activity of all these muscles was recorded via EMG.Results: Data analysis was done by repeated measure ANOVA with tukey corrections for pair-wise comparison of muscle activity with all positions of hip for each muscle. The results showed a muscle activity for VMO minimal activity is found in lateral rotation of hip and maximum activity is found in medial rotation of hip. And for VL minimal activity is found in neutral rotation of hip and maximum activity is found in medial rotation of hip. So the ratio of VMO/VL is found minimum in lateral rotation and maximum in medial rotation. (p>0.05). Conclusion:It can be concluded from this study that in semisquat position medial rotation of hip gives better activation for Vastus medialis obliqus muscle and increase ratio of VMO/VL. So, it can be used in knee rehabilitation program.