ACUTE EFFECTS OF TECHNICAL INSTRUCTIONS ON SPRINT ACCELERATION TECHNIQUE AND PERFORMANCE

This study investigated the acute effect of verbal technical instructions intended to alter attentional focus during a 10 m sprint. Team sports athletes (n = 15) completed maximal effort sprints under a control condition and two experimental conditions: internal and external focus. Lower-body kinematic and external kinetic data were collected near the 5 m mark. Total sprint time was longer in both experimental conditions than the control condition (p < 0.05). Both experimental conditions altered ankle and knee angles at touchdown and led to more vertically oriented ground reaction forces (all p < 0.05). Whilst these instructions were detrimental to performance, the results support the importance of technical ability for sprint acceleration. Future studies should seek to identify instructions, potentially used within training programmes, which could be beneficial to performance

Alterations to the orientation of the ground reaction force vector affect sprint acceleration performance in team sports athletes

A more horizontally oriented ground reaction force vector is related to higher levels of sprint acceleration performance across a range of athletes. However, the effects of acute experimental alterations to the force vector orientation within athletes are unknown. Fifteen male team sports athletes completed maximal effort 10-m accelerations in three conditions following different verbal instructions intended to manipulate the force vector orientation. Ground reaction forces (GRFs) were collected from the step nearest 5-m and stance leg kinematics at touchdown were also analysed to understand specific kinematic features of touchdown technique which may influence the consequent force vector orientation. Magnitude-based inferences were used to compare findings between conditions. There was a likely more horizontally oriented ground reaction force vector and a likely lower peak vertical force in the control condition compared with the experimental conditions. 10-m sprint time was very likely quickest in the control condition which confirmed the importance of force vector orientation for acceleration performance on a within-athlete basis. The stance leg kinematics revealed that a more horizontally oriented force vector during stance was preceded at touchdown by a likely more dorsiflexed ankle, a likely more flexed knee, and a possibly or likely greater hip extension velocity