| Popis: |
BACKGROUND: Different sized parachutes may alter applied resistance during parachute towing (PT), changing results of resisted sprint training interventions. Thus, it was hypothesized that there may be significant net anteroposterior ground reaction force and impulse differences due to parachute size towed. METHODS: Fifteen male sprinters completed control and PT sprints over a 50 m force platform system. Estimated aerodynamic drag, ground reaction forces and kinematic differences during the maximum speed phase were compared between control (no parachute) and PT trials with small (0.39 m2), medium (0.54 m2) and large (0.72 m2) parachutes, using One-way ANOVA (significance set at P < .050) with Tukey’s HSD post hoc (Critical Q value = 3.746) tests. RESULTS: No significant (P > .050) step length, step frequency, propulsive mean force, vertical mean force or vertical impulse differences between trials. There was a significant anteroposterior impulse difference (P < .001, Q = 4.574) between small and medium PT, but no differences between medium and large PT. Compared to the control trial, all PT trials increased anteroposterior net mean force (P < .001), anteroposterior net impulse (P |
