Stepping over obstacles of different heights and varied shoe traction alter the kinetic strategies of the leading limb

This study aims to investigate the effects of shoe traction and obstacle height on friction during walking to better understand the mechanisms required to avoid slippage following obstacle clearance. Ten male subjects walked at a self-selected pace during eight different conditions: four obstacle heights (0%, 10%, 20% and 40% of limb length) while wearing two different pairs of shoes (low and high traction). Frictional forces were calculated from the ground reaction forces following obstacle clearance, which were sampled with a Kistler platform at 960 Hz. All frictional peaks increased with increases in obstacle height. Low traction shoes yielded smaller peaks than high traction shoes. The transition from braking to propulsion occurred sooner due to altered control strategies with increased obstacle height. Collectively, these results provided insights into kinetic strategies of leading limb when confronted with low traction and high obstacle environments. This study provides valuable information into the adaptations used to reduce the potential of slips/falls when confronted with environments characterised by low shoe-floor friction and obstacles. It also provides the necessary foundation to explore the combined effects of shoe traction and obstacle clearance in elderly people, more sensitive to slippage.