Adjustment of step frequency in obstacle avoidance during running

Purpose This study aimed to investigate the variations in step rate for obstacle avoidance during running. While numerous studies have investigated obstacle avoidance during walking, our understanding of obstacle avoidance during running is still relatively limited. For this purpose, videos of the 3000-metre steeplechase were observed. Methods Data were collected from the men’s 3000 m steeplechase races. Performances from 75 male athletes were analysed. The 3000 m steeplechase race consisted of seven laps. Analysis focused on the 10 steps immediately preceding obstacle clearance. All steps from the participants were digitalised using Kinovea (version 0.9.5). The step rate of ten steps before the hurdle were subjected to two-way ANOVAs with repeated factors of lap (lap1/lap2/lap3/lap4/lap5/lap6/lap7) and step (step1/step2/step3/step4/step5/step6/step7/step8/step9/takeoff). All statistical analyses were conducted using JASP (0.19.3), with a significance level of <i>p</i> < 0.05. Results There was a significant interaction between lap and step [F<sub>(54,3996)</sub> = 1.97, p = 0.01, η<sup>2</sup> <sub>p</sub> = 0.03]. In terms of step, the step rate increased from five steps before the takeoff (<i>p</i> < 0.05). Consistent with findings on obstacle avoidance during walking, our results demonstrated that runners initiate preparatory adjustments to their step rate roughly five steps prior to encountering an obstacle. In addition, the step rate just prior to obstacle avoidance is highly influenced by fatigue. In terms of laps, a significant difference was observed in steps 7, 8, 9, and 10 (<i>p</i> < 0.05). Conclusions Our results demonstrated that runners initiated preparatory adjustments to their step rate approximately five steps prior to obstacle avoidance. Training for the 3000 m steeplechase should not only focus on enhancing endurancerelated physiological capacities but also on developing hurdle technique, particularly the preparatory phase in the five steps leading up to the hurdle.