Do older adults with and without a history of falls show different gait patterns in response to individualized treadmill perturbations?

Dynamic reactive balance is key to avoid falls during walking and can be challenged with treadmill-based gait perturbations. The use of mechanical gait perturbations to measure reactive dynamic balance performance, is discussed to identify individuals at risk of falling. Gait speed and perturbation intensity, are often standardized in study populations. In heterogeneous study populations, this entails the risk of either overburdening the participants or failing to adequately challenge them. Are gait parameters and compensatory steps, after mechanical treadmill-based perturbations using perturbation intensities at the individual single step threshold and preferred walking speed, different between younger and older adults with or without a history of falling? In this study, 86 younger and older adults with and without a history of falls completed two treadmill-walking trials with mediolateral and anteposterior perturbations. Step length and step width were analyzed before and after perturbations using ANOVA with repeated measures. The adjustments of both parameters to individualized mediolateral perturbations differed between younger and older participants, while between older adults with and without a history of falls, only small differences in step width ( p < 0.001, η p 2 = 0.141) were observed. Individually tailored treadmill-perturbations can be safely applied in older adults. Compensatory steps as a reaction to perturbations differ between younger and older adults. However, at the individual limit of balance control, differences between older adults with and without a history of falls are small. • Step length and step width after individualized mediolateral perturbations are longer affected in older adults than in younger adults. • Older adults with a history of falls do not modulate their step width as much as older adults without a history of falls after individualized perturbations • Older adults increase their step width for a prolonged time after balance is restored