Understanding cutting maneuvers – The mechanical consequence of preparatory strategies and foot strike pattern

摘要

ObjectivesThis study investigated the relation of different previously reported preparatory strategies and musculo-skeletal loading during fast preplanned 90° cutting maneuvers (CM). The aim was to increase the understanding of the connection between whole body orientation, preparatory actions and the solution strategy to fulfil the requirements of a CM. MethodsThree consecutive steps of anticipated 90° CMs were investigated in a 3D movement analysis setup. Pelvis orientation clustered the subjects in two groups, with minor and major pre-orientation. To understand the impact of body orientation on the specific movement strategy, joint angles, moments and energy as well as spatio-temporal parameters of the movement were analysed. ResultsEarly rotation of the body was initiated by a small step width during braking resulting in a more constant path velocity of the centre of mass and less demands on the hip- and knee surrounding muscles. Minor pre-orientation required increased work of the hip muscles to decelerate, reaccelerate and in particular to rotate the body. This resulted in an increase of contact time. While pre-orientation in combination with fore-foot striking led to a strategy where energy absorption and generation is mainly generated by the ankle plantar flexors, less pre-orientation and rear-foot striking resulted in a knee- and hip dominant strategy. ConclusionStep width before transition strongly determined pre-orientation and overall body position. Both strategies fulfil the requirements of a CM but induce different demands regarding muscular capacities. Pelvis orientation and step width are easy-to-use assessment parameters in the practical field.