Ground-Reaction Forces during Form Skipping and Running

Abstract

Context: Form skipping has been used to help injured athletes progress to running. Because little research has been done on form-skipping mechanics, its justification as a progression to running exercises is unclear. Objective: To compare ground-reaction forces (GRF) during form skipping and running in healthy subjects at clinically relevant speeds, 1.75 m/s and 3.83 m/s, respectively. Design: Dependent t tests ( α = .05). Setting: Sports-injury research center. Participants: 9 male college athletes (age 20 ± 1.33 years, mass 848.4 ± 43.24 N, height 1.80 ± 0.07 m). Main Outcome Measures: Average ( Fz avg ) and maximum ( Fz max ) vertical GRF and ( Fy ) braking impulse were compared. Results: Fz avg and Fz max were greater during running than during form skipping ( P < .05). Braking impulses were not different ( P > .05). Conclusions: It appears that Fz , but not the Fy , GRF might explain why form skipping might be an appropriate progression to running.