Comparison of Joint-Level Kinetics During Single-Leg and Double-Leg Weightlifting Derivatives

Hayashi, R, Yoshida, T, and Kariyama, Y. Comparison of joint-level kinetics during single- and double-leg weightlifting derivatives. J Strength Cond Res 37(5): 1017-1022, 2023-Humans have different 3-dimensional biomechanical characteristics of the lower extremities during locomotion with one and both legs. These biomechanical characteristics may also be observed in the weightlifting derivatives. This study aimed to compare the 3-dimensional joint kinetics of the lower extremities during the single-leg hang power clean (SHPC) and double-leg hang power clean (DHPC). Ten male track and field athletes performed the SHPC and DHPC using external loads of 30, 60, and 90% of one repetition maximum (1RM). The 1RMs in SHPC and DHPC were measured separately, and the external loads at 30, 60, and 90% of the 1RM used were determined based on the different 1RMs in SHPC and DHPC. We calculated the joint moment and joint power of the SHPC and DHPC using a motion capture system and force platforms. The hip abduction moment and power of the SHPC were significantly greater than those of the DHPC under all external loads ( p < 0.05). In addition, ankle joint moment at all external loads and joint power at 90% of 1RM was greater for SHPC than for DHPC ( p < 0.05). Furthermore, although hip (extension-flexion) and ankle joint kinetics in SHPC and DHPC showed similar load dependence, hip abduction axis kinetics was not load dependent. These results suggest that the hip (abduction-adduction) and ankle joint kinetics in SHPC are greater than in DHPC, but hip (abduction-abduction) kinetics in SHPC is not load independent.