Effects of minimal, maximal and conventional footwear on whole-body and muscle metabolic power during running

The aim of this investigation was to examine running biomechanics in minimal, maximal and conventional running shoes using a musculoskeletal simulation approach to evaluate their effects on whole-body and muscle-level metabolic power. Fifteen healthy male runners completed overground trials in all three footwear conditions at a controlled speed of 4.0 m/s. Kinematic data were collected using an eight-camera motion-capture system, and ground reaction forces were obtained from an in-ground force plate. Musculoskeletal simulations quantified whole-body metabolic power as well as joint and muscle-level mechanical and metabolic outputs. Comparisons between footwear conditions were performed using linear mixed-effects models with repeated measures. Whole-body metabolic power did not differ between maximal (11.35 W/kg), minimal (11.07 W/kg) and conventional (11.26 W/kg) shoes. In contrast, joint mechanics and muscle-level energetics showed significant differences. Knee power generation and absorption were significantly greater in maximal (generation = 8.05; absorption = −18.07 W/kg) and conventional (generation = 8.20; absorption = −17.00 W/kg) footwear than in minimal (generation = 6.53; absorption = −12.81 W/kg). Ankle power generation and absorption were significantly higher in minimal footwear (generation = 15.89; absorption = −11.96 W/kg) than in conventional (generation = 14.23; absorption = −10.40 W/kg) or maximal (generation = 13.15; absorption = −9.37 W/kg) footwear. Stance-limb peak knee extensor power was higher in conventional (6.38 W/kg) and maximal (5.85 W/kg) than in minimal (5.48 W/kg) footwear. Whole-body metabolic power did not differ between footwear conditions, yet distinct changes in joint mechanics and muscle-level metabolic power were observed. In minimal footwear, these changes reflected a shift in the distribution of mechanical and metabolic work from the knee to the ankle.