Failed table-tennis forehand drives are characterised by higher ground reaction forces and greater centre-of-pressure excursion in amateur players: a within-participant trial-level study

Background Forehand-drive errors in table tennis are often attributed to insufficient force production or racket speed. Whether successful and failed returns differ in support-limb mechanics within the same player remains unclear. Methods Fourteen amateur players performed standardised forehand drives against machine-fed topspin balls. Trials were classified as successful when the ball crossed the net and landed legally on the opposite half of the table; net and out-of-bounds returns were classified as failed. Ground reaction force (GRF) and combined centre-of-pressure (COP) variables were extracted from synchronised force plates. Trial-level linear mixed-effects models were fitted for 189 kinetic trials (140 successful, 49 failed), with stroke outcome as a fixed effect and participant as a random intercept. Benjamini-Hochberg false-discovery-rate correction was applied to 30 prespecified GRF/COP variables. Results Fifteen GRF/COP variables survived correction. Failed trials showed higher anteroposterior and vertical GRF magnitudes, greater combined-COP mean speed, path length, mediolateral fluctuation and anteroposterior/mediolateral range, and a later anteroposterior force peak. Sensitivity analyses showed that the same GRF/COP pattern generally persisted, although some short-window effects were reduced. Exploratory markerless posture-kinematic indicators were analysed separately and interpreted only as hypothesis-generating auxiliary findings. Conclusions In this amateur forehand-drive task, failed returns were associated with greater, not lower, support-limb force output and COP excursion. These variables may characterise support-base organisation during forehand-drive errors, but causal and training implications require longitudinal or interventional confirmation.