Lower-limb coordination changes following a six-week training intervention that elicited enhancements to maximum velocity sprint performance

Alterations to intra- and inter-limb coordination with improved maximal velocity performance remain largely unexplored. This study quantified within-day variability in lower-limb segmental coordination profiles during maximal velocity sprinting and investigated the modifications to coordination strategies in 15 recreationally active males following a six-week period comprised of a multimodal training programme (intervention group (INT); n = 7) or continued participation in sports (control group; n = 8). The INT demonstrated a large decline (effect size = -1.54) in within-day coordination profile variability, suggesting potential skill development. Thigh-thigh coordination modifications for the INT were characterised by an earlier onset of trail thigh reversal in early swing (26 vs. 28% stride) and lead thigh reversal in late swing (76 vs. 79% stride), rather than increases in overall time spent in anti-phase. Moreover, an increase in backwards thigh-dominant, thigh-shank (effect size, 95% CIs: 0.75, 0.17 to 1.33) and shank-dominant, shank-foot (0.76, -0.17 to 1.68) rotations during late swing likely facilitated more aggressive acceleration of the foot prior to touchdown, contributing to reduced touchdown distance and more favourable lower-limb configuration at initial ground contact. These novel findings provide empirical support for the role of longitudinal coordination modifications in improving maximal velocity performance. SUMMARY STATEMENTCoordination during the swing phase was more modifiable than during stance, with earlier reversal of antiphase thigh-thigh and backwards thigh-shank and shank-foot rotations in late swing observed with improved performance.