Influence of terrain on metabolic and temporal gait characteristics of unilateral transtibial amputees.

The difficulties confronted by amputees during overground walking are rarely investigated. In this study, we evaluated, in real-world situations, the influence of ground surface on walking in young, active amputees by measuring temporal and spatial gait parameters (free walking speed [FWS], step length [SL], step rate), energy expenditure (EE) (e.g., oxygen uptake, oxygen cost [O(2)C]), and Rating of Perceived Exertion (RPE). Ten active transtibial amputees and ten nondisabled control subjects walked at self-selected speeds on three types of ground surface (asphalt, mown lawn, and high grass). No significant differences were observed between the two groups on asphalt and mown lawn. Differences between nondisabled subjects and amputees occurred for FWS (p = 0.03) and O(2)C (p = 0.04) on asphalt and mown lawn and for all variables in high grass. When amputees (even though very active) were exposed to a particularly difficult environment, their FWS decreased (p = 0.008) and their EE and RPE increased (p = 0.005) compared with nondisabled subjects. In high grass, both groups reduced their self-selected speeds (-15% for control subjects and -16% for amputees). Control subjects reduced their velocity by reducing both SL (-8.7%) and cadence (-7.1%), whereas amputees reduced their velocity by reducing SL (-17%) only.