Contribution of lower limb eccentric work and different step responses to balance recovery among older adults.

Abstract Falls during walking reflect susceptibility to balance loss and the individual's capacity to recover stability. Balance can be recovered using either one step or multiple steps but both responses are impaired with ageing. To investigate older adults’ ( n  = 15, 72.5 ± 4.8yrs) recovery step control a tether-release procedure was devised to induce unanticipated forward balance loss. Three-dimensional position–time data combined with foot-ground reaction forces were used to measure balance recovery. Dependent variables were; margin of stability (MoS) and available response time (ART) for spatial and temporal balance measures in the transverse and sagittal planes; lower limb joint angles and joint negative/positive work; and spatio-temporal gait parameters. Relative to multi-step responses, single-step recovery was more effective in maintaining balance, indicated by greater MoS and longer ART. MoS in the sagittal plane measure and ART in the transverse plane distinguished single step responses from multiple steps. When MoS and ART were negative (