The purpose of this study was to determine how time constraints during stopping in sports affect lower limb muscle activation strategies in both the termination and stability steps. Rapid deceleration is common in both recreational and professional sport and has previously been associated with lower limb injury. To investigate control differences between anticipated and unanticipated stopping, total muscle activation and directed cocontraction ratios were used to analyse lower limb muscle activation. Increased plantar flexor and knee flexor activity was found during the pre-contact and weight acceptance phases of unanticipated stopping compared with anticipated stopping. These results support the hypothesis that lower limb muscle activity is altered when the task is unanticipated, which may place athletes at higher risk of lower limb injury in sport
