Comparison and Analysis of Muscle Acitivities on Angles of Knee Joint during Squat Exercise

The purpose of this study was to draw comparison of lower limb muscles on degrees of knee joint during squat exercise(60°, 75°, 90°, 100°) with electromyogram(iEMG) analysis technique and to show the muscle activation properties. This study carried out an experiment with 20 young men in school K university who have done weight training(n = 20 ; mean height 178.87 ± 5.4 cm ; mass 78.41 ± 12.3kg ; age 22.5 ± 2.2years). We checked activation of muscle using surface electromyography when squat performed 2 times at 80% of 1RM. one way repeated ANOVA which was used to identify significant differences among 4 different angle of knee squat. When a significant difference was found in results, post hoc analysis were conducted by using the Contrast test procedure. An alpha level of .05 was used to determine the significance level. We analyzed activation of lover limb muscle during squat. As a result of this study, muscular activities of rectus femoris, vastus medialis and vastus laterlis were increased with changing angle of knee joint. on the other hand muscle activities were reduced at 100° except 60°, 75°, 90°.