How Subjective Effort Affects Forehand Topspin Kinematics in Table Tennis

This study aims to clarify the effects of varying subjective effort levels on the movement characteristics of the forehand topspin stroke in competitive table tennis and to provide insights for technical instruction. Ten skilled male table tennis players (right-handed; with national tournament experience) participated in the study. Each participant performed forehand topspin strokes at five subjective effort levels: 60%, 70%, 80%, 90%, and 100%. Participants repeated trials until they successfully executed at least three valid strokes per effort level. Stroke success was determined based on swing smoothness and ball trajectory after impact. A motion capture system was used for movement analysis, with a sampling frequency of 240 Hz. To examine the effects of subjective effort levels on key kinematic variables, repeated-measures analysis of variance (ANOVA) was conducted. As subjective effort increased, greater rotational motion of the pelvis, thorax, and upper limbs was observed. Additionally, counter-rotation movements of the torso became more pronounced, and the thoracic flexion angle decreased. Despite these changes, the duration from the backswing to impact remained consistent across effort levels. These findings suggest that increased effort levels alter stroke mechanics, particularly by enhancing trunk rotation and counter-rotation movements. From a coaching perspective, it may be beneficial to not only focus on technical aspects of stroke execution but also to provide guidance on force modulation based on observed movement patterns.This study contributes to the development of practical instructional strategies in sports coaching by deepening our understanding of how effort levels influence stroke mechanics.