The electromyography activities of the quadriceps muscles during hip rotations in closed kinetic chain tasks in healthy women

Considering the important role of vasus medialise oblique in pattelofemoral joint function and the necessity of designing appropriative exercises for it, the purpose of the present study was to investigate electromyography activity of quadriceps muscle in deferent hip rotation position in closed kinetic chain in healthy women. The current quasi-experimental study was conducted on 35 healthy women chosen via simple nonrandomal sampling. Electromyography activity rectus femoris, vastus medialise oblique, and vastus lateralise were recorded with surface electrodes in 15, 30, and 45 degrees of internal and external rotation and neutral position of hip with participants risen onto their toes. Normalized data was analyzed in excel. The outcomes of repeated measure analysis revelaed that there was a meaningful deference in 15 degree of external rotation (p=0.039), neutral position (p=0.003), 15 degree internal rotation (p=0.003), and at the end of internal position (p=0.015). Pair wise comparison between muscles activity and bonferroni showed vastus lateralise activity in 15 degree external rotation (p=0.039), neutral position (p=0.003), 15 degree internal rotation (p=0.003), and at the end of internal position (p=0.015) was more than rectus femoris muscle. Other pair comparisons between vastus medialis oblique and vastus lateralise, and vastuse medialise oblique and rectus femoris were not observed to be meaningful. Based on the outcomes of the present study, the average vastus lateralise activity was the highest in all positions and the position studied in the current study did not lead to increase in vastus medialise oblique as a medial dynamic stabilizer compared to vastus lateralise.