プレッシャーが運動スキルに及ぼす影響

The first purpose of this doctoral thesis was to investigate the behavioral aspect, such as kinematics and kinetics, of the performance of a motor skill under pressure. The second was to investigate the relationships among psychological aspect (attentional focuses), physiological aspect (arousal), and behavioral aspect (kinematics and kinetics) under pressure. The golf putting tasks were used in this thesis. This thesis was consisted of four experiments.

Experiment 1 investigated changes in movement kinematics and attentional focuses when expert and novice golfers performed a golf putting task under pressure. A twodimensional analysis of movement kinematics revealed that, under pressure, the amplitudes of arm and club movements decreased on the backswing. Speed of arm and club movements decreased on the foreswing, in both experts and novices. Furthermore, neither experts nor novices changed their attentional focus under pressure.

Experimental 2 showed the same kinematic changes of Experiment 1 when novices performed a golf putting task under pressure. However, the EMG activity of the flexor carpiulnaris muscle and the extensor carpi radialis muscle of the right forearm showed no significant changes under pressure. Furthermore, performance decrements under pressure were caused by high inter-trial variability of the clubmovement amplitudes during backswing and angular displacement of the right wrist during downswing.

Experiment 3-1 indicated that the conscious control of movements under pressure increased movement variability and resulted in inconsistent ball locations. In addition, the distraction under pressure led to smaller and slower movements, but the increment of HR under pressure led to faster movements. Furthermore, experiment 3-2 indicated that a significant correlation between the increment of HR and the increased movement acceleration under pressure.

Whereas the previous studies have explained the choking phenomenon from different viewpoints related to attentional changes, such as the conscious control of movements and the distraction, these results of this doctoral thesis suggested that different attentional shifts under pressure are related to different kinematic changes. In addition, the kinematic changes under pressure were possibly caused by the influences of strategy modification and/or emotional response.