Effects of different-states-squatting on surface electromyography of thigh muscles and lumbar multifidus muscle / 实用医学杂志

ABSTRACT

Objective This work aimed to observe averaged electromyogram(AEMG)changes in surface electromyography(sEMG)of thigh muscles and lumbar multifidus muscles in different states of squat training. Then,to find out which is the most effective for squat training. Methods A total of 46 healthy volunteers were selected and divided into two groups,namely,with and without leaning against the wall.sEMG was used to record vastus lateralis muscle,vastus medialis muscle,biceps femoris muscle,and lumbar multifidus muscles at differ-ent knee flexion angles(30°,45°,60°,and 75°). AEMG was analyzed by repeated-measures analysis of vari-ance. Results Different knee flexion angles exerted significant effects on AEMG of all tested muscles(P <0.001).Whether leaning against the wall to squat had a significant impact on AEMG of biceps femoris muscle,but not on vastus lateralis muscle,vastus medialis muscle and lumbar multifidus muscles. Significant difference was detected in interactions of knee flexion angle,and the same to the factor of with and without leaning against the wall on examined AEMG of the thigh muscle,but not for lumbar multifidus muscles. Multiple comparisons showed,the AEMG level of the tested muscles was significantly increased when the knee flexion angles was 75°. Conclusions With increased knee flexion angle,muscle activation has enheanced for vastus lateralis muscle, vastus medialis muscle,biceps femoris muscle and lumbar multifidus muscles. Squatting without leaning against the wall exerts a more marked influence on activation of biceps femoris muscle,but no activation for vastus lateralis muscle,vastus medialis muscle and lumbar multifidus muscles.