Contributions of lower limb segments in rugby place kick

Interactions between lower limb segments in rugby place kick were studied through segment interaction analysis. In this study we collected motion data during maximal speed rugby kicking from skilled rugby kickers and developed a three-dimensional (3D) anatomical based biomechanical model to quantify lower limb joint kinematics and kinetics using an inverse dynamics approach. A proximal-to-distal movement sequence was observed for rugby place kick motions and knee flexion/extension was found to contribute the most to the kicking speed. Muscle torque (MT) counteracts with interaction torque (IT) for the hip joint and knee joint. The magnitude of MT is greater than IT and the rotation is driven by MT with the assistance of torque from gravity. Before ball contact, both IT and MT for the distal joint (knee) rapidly change their directions and achieved a maximal value. Further analysis of the results indicates that the counteracting relationship might have the advantage of generating maximal kicking speed and stabilizing the knee joint during ball impact.