Performance in elite discus throwing is governed by phase-specific timing and velocity transfer

This study examined the associations between phase-specific kinematic variables and discus throw performance in elite throwers. Video recordings of 23 male (63.39 ± 4.19 m) and 16 female (59.74 ± 7.25 m) discus throwers were analysed to obtain kinematic variables describing phase durations, centre-of-mass (COM) velocities, discus paths and velocities, torso and hip-shoulder-arm positions, and pelvis and torso rotational velocities. Linear mixed models were used to identify phase-specific kinematic variables associated with throwing distance while accounting for repeated trials within athletes. Phase-specific kinematic variables positively associated with throwing distance were 1) a longer entry phase paired with shorter transition and delivery phases, 2) faster horizontal COM velocity during the flight phase, 3) peak horizontal discus velocity during the delivery, and 4) slower pelvis rotational velocity during the transition and faster torso rotational velocity during the delivery. Measures of torso lean and hip-shoulder-arm separation angles were not associated with throwing performance. These findings indicate that elite discus throw performance is governed more by phase-specific timing as well as control and regulation of linear and rotational velocities than by isolated postural characteristics. Further, effective technique appears to reflect the ability to establish favourable mechanical conditions early and express them efficiently during the delivery phase.