Abstract
The purpose of this study was to investigate the anticipatory postural control of the trunk and lower extremities in sudden stops from accelerated runs. Participants performed sudden stops from accelerated runs under self-timing and reaction conditions. In the self timing condition, the participants were able to plan the timing to stop and were asked to suddenly stop at their preferred timing. In the reaction condition, the participants could not plan the timing to stop and were asked to stop as quickly as possible immediately after the light stimulus was turned on. The results showed the braking distance required for the sudden stop was significantly shorter in the self timing condition than that in the reaction condition. Furthermore, only in the self-timing condition, the hip joint flexion was observed prior to the ground contact of the braking leg for the sudden stop, and its timing preceded that of the knee joint. Therefore, the kinematic anticipatory postural control in sudden stops from accelerated runs was shown to be characterized by prior hip joint flexion.