Gait stability in response to platform, belt, and sensory perturbations in young and older adults

Abstract

Perturbation-based gait assessment has been used to quantify gait stability in older adults. However, knowledge on which perturbation type is most suitable to identify poor gait stability is lacking. We evaluated the effects of ipsi- and contra-lateral sway, belt acceleration and deceleration, and visual and auditory perturbations on medio-lateral (ML) and anterior-posterior (AP) margins of stability (MoS) in young and older adults. We aimed to evaluate (1) which perturbation type disturbed the gait pattern substantially, (2) how participants recovered, and (3) whether recovery responses could discriminate between young and older adults. Nine young (25.1 ± 3.4 years) and nine older (70.1 ± 7.6 years) adults walked on the CAREN Extended (Motek BV, The Netherlands). The perturbation effect was quantified by deviation in MoS over six post-perturbation steps compared to baseline walking. Contra-lateral sway and deceleration perturbations resulted in the largest ML (1.9–4 times larger than other types) and AP (1.6–5.6 times larger than other types) perturbation effects, respectively. After both perturbation types, participants increased MoS by taking wider, shorter, and faster steps. No differences between young and older adults were found. We suggest to evaluate the potential of using contra-lateral sway and deceleration perturbations for fall risk identification by including both healthy and frail older adults. Graphical abstractMargins of stability during steady state (left) and perturbed (right) gait to quantify reactive gait stability in response to various perturbation types in young and older adults. Electronic supplementary materialThe online version of this article (10.1007/s11517-018-1855-7) contains supplementary material, which is available to authorized users.

Transfer and retention effects of gait training with anterior-posterior perturbations to postural responses after medio-lateral gait perturbations in older adults

“…Step time, stance time and swing time were determined from gait events, and step length and step width were calculated as the AP and ML distances between the left and right foot position at heel strike (Roeles et al, 2018).…”

“…This simulates a slip, in which the striking foot slips forward, inducing backwards balance loss. The intensity and type of perturbations were based on pervious work (Roeles et al, 2018), showing treadmill decelerations and contralateral sways to be the most challenging types. The order of perturbations, as well as the perturbed leg and the time between perturbations (10-60 s), was randomized but kept the same for all participants.…”

Age-related differences in gait adaptations during overground walking with and without visual perturbations using a virtual reality headset

“…An over-ground gait training paradigm with continuous visual perturbations could be used to train subjects to refine the relative weighting of different sensory feedbacks, through the exposure to visual perturbation in a more ecological condition that is not affected by the limitations of treadmill walking. While mechanical perturbations could generate similar 22 or greater 36 disruptive changes in gait and balance, visual perturbations allow to still affect balance without physically applying forces to the body that may increase the risk of injury, especially for more frail elders. Moreover, visual perturbations delivered by commercially available VR headsets, like the one used in this study, could have multiple benefits.…”

Anticipatory control of human gait following simulated slip exposure

“…A convenience sample of 30 healthy young adults was recruited in this study (17 males, 13 females, 21.6 ± 2.2 years old, body mass: 70.1 ± 9.8 kg, body height: 1.78 ± 0.085 m, leg length: 0.92 ± 0.039 m), based on similar studies in the field of balance control during perturbed gait 21,22 . Participants were excluded if they had any prior experience with slip-like perturbation experiments or if they had any neurological, cognitive, or orthopaedic impairments that could affect the outcome of the experiment.…”