Organization of motor system degrees of freedom during the soccer chip: an analysis of skilled performance

This study investigated how motor system degrees of freedom were organized as skilled players performed a soccer chipping task. Using an intra-participant analysis, inter-individual kinematics and performance differences were investigated to determine the features governing coordination of skilled chipping actions. Five skilled participants were studied as they performed 10 soccer chips to one target position and another 15 soccer chips to three positions, all with different specific height and accuracy task constraints. Although a ‘global coordination pattern’ was identified for skilled soccer chipping, subtle inter-individual differences in coordination, displacement of center of mass (COM), selected kinematic variables for the kicking limb and the role of the non-kicking limb were also observed. It was noted that participants were able to adapt foot velocity to different target positions in successfully meeting the task goal. Results highlighted advantages of examining intra-participant data for understanding how skilled performers re-organize motor system degrees of freedom in achieving functional movement behaviors.