Effect of Load Direction on Lower Extremity Function in Healthy Adult Women during Bulgarian Split Squat

The purpose of this study was to compare the effect of load direction on the kinematic characteristics of the lower extremities during the Bulgarian split squat in healthy adult women(n=29). The study measured lower extremity muscle activation and dynamic Q-angle in three load directions(ipsilateral, contralateral, and bilateral) during the Bulgarian split squats. As a result of comparing lower extremity muscle activation according to load direction, statistically significant differences were observed in the gluteus medius, semitendinosus, and biceps femoris during the eccentric and concentric contraction phases, and in the rectus femoris during the concentric contraction phase. The dynamic Q-angle was found to be statistically smaller in the ipsilateral load than in the contralateral and bilateral loads according to load direction. These results suggest that contralateral loading may be considered an effective strategy for activating the gluteus medius and hamstrings and promoting hip joint stability, ipsilateral loading for rectus femoris activation and joint stability, and bilateral loading for overall stability.