Biomechanical Differences Between Ipsilateral and Contralateral Change-Of- Direction Movements Using the Same...

Change-of-direction (COD) movements are critical for predicting injury risk or identify sport performance. Multiple studies have examined contralateral COD (contra-COD) comprehensively, but few studies have examined ipsilateral COD (ipsi-COD). This study investigated the kinetic and kinematic parameters of the same planting foot during ipsi-COD and contra-COD movements. In total, 29 recreational team sport players performed 60° ipsi-COD and contra-COD movements. Biomechanical data were collected using a three-dimensional force plate and a motion capture system. The ipsi-COD task exhibited a 6% shorter contact time than the contra-COD task. In addition, ipsi-COD resulted in a significantly greater ankle pronation-supination range (+27%), smaller inversion-eversion range (-19%), and decreased plantarflexion-dorsiflexion range (-37%). Lower ground reaction forces (horizontal: -14%, vertical: -32%, resultant: -14% to -279%) and impulse values (horizontal: -24%, vertical: -23%, resultant: -24%) were observed for ipsi-CODs than for contra-CODs. The musculoskeletal structure of the lower limbs provides an anatomical advantage for excessive eversion during ipsi-COD, leading to a more rounded execution path compared with contra-COD. The differences in contact time, ankle range of motion, and ground reaction force in ipsi-COD may result from joint alignment, force application techniques, and movement execution strategies. The observed phenomenon of shorter contact time with lower ground reaction force and smaller ankle range in ipsi-COD offers new insights for future studies investigating COD mechanics across different movement contexts.