PURPOSE

To quantify real-time hand-foot coupling in tennis and test whether the coupling pattern differs by playing standard.

METHODS

Fifteen nationally certified second-level male athletes and fifteen recreational beginners performed multi-directional swings, alternating forehand-backhand groundstrokes and serve-and-volley sequences while tri-axial ankle acceleration and racket-grip force were synchronously recorded in wearable inertial measurement units (IMUs). Grip metrics (mean force, peak force, force duration) and acceleration magnitudes were analysed with MANOVA and Hedges' g effect sizes, followed by the Benjamini-Hochberg correction (α = 0.025).

RESULTS

Across tasks, athletes showed higher mean ankle acceleration (standardised mean difference, Hedges' g) but 45% lower mean grip force (Hedges' g = -1.28; both < 0.01). The association between acceleration and grip metrics was moderate-to-strong and negative in athletes (r = -0.62 with mean grip force; r = -0.69 with force duration), whereas beginners exhibited moderate-to-strong positive correlations (r = 0.48-0.73).

CONCLUSION

We quantified hand-foot coordination in tennis by synchronising tri-axial ankle acceleration with calibrated racket-grip force across three match-realistic tasks. Relative to beginners, athletes demonstrated an inverse coupling between ankle acceleration and grip-force metrics, whereas beginners showed a direct coupling, consistent with our purpose of quantifying coordination via synchronised wearable sensors.