Effect of cross-slope angle on running economy and gait characteristics at moderate running velocity.

Abstract

Outdoor running surfaces are designed with a cross-slope, which can alter kinetic and kinematic gait parameters. The purpose of this study was to evaluate running economy, gait characteristics, and muscle activation while running on a surface with cross-slopes similar to those encountered on roads and trails. Eleven recreational runners (females n = 6) completed 5-min running trials on a treadmill at 10kmh-1 with cross-slopes of 0, 1.15, 2.29, and 6deg in a randomized order. There were no significant differences in VO2, HR, RER, or VE across cross-slope conditions. Compared to 0deg of cross-slope, ground contact time and duty factor increased at 2.29 and 6deg, with significant decreases in absolute and relative flight times. Rear foot angles increased in the upslope leg at 2.29 and 6deg cross-slopes and decreased in the downslope leg at 6deg compared to 0deg of cross-slope, with differences between legs for the 2.29 and 6deg conditions. Knee flexion at foot strike increased in the upslope leg at a 6deg cross-slope. Vastus lateralis, biceps femoris, gastrocnemius, and tibialis anterior activation were not affected by the cross-slope conditions. While cross-slopes up to 6deg result in changes to some gait kinematics, these effects do not impact running economy at moderate running velocity.