Abstract
Background : The purpose of this study was find out more effective method for improving muscle strengthening in lower extremities according squatting exercise method among knee joint angle 45, 60, 90 degree and between gym ball behind back and wall. Methods : Participants were 21 university students(males 10, females 11) who didn't have any problem with orthopedic surgery. We divided participants to two groups with gym ball group and wall group. Gym ball group were performance squatting exercise with gym ball behind back. Each group had performance squatting exercise according knee joint angle 45, 60, 90 degree. We collected data from E.M.G of Biceps femoris, Gastrocnemius, Vastus medialis and lateralis, Tibialis anterior in lower extremity according knee joint angle 45, 60, 90 degree of each groups. We analyzed data using by ANOVA and ANCOVA of SPSS PC ver. 12.0 in order to determine more effective method according various squatting exercise. Results : Each groups show significantly difference value of biceps femoris, vastus lateralis and medialis, tibialis anterior, gastrocnemius lateralis and medialis among knee joint angle 45, 60, 90 degree. But there was no significantly difference value between gym ball group and wall group according knee joint angle. Conclusions : We suggested that squatting exercise with gym ball was more effective method improving lower extremity muscle strengthening, and changing knee joint angle was more effective compared than continued knee joint angle.