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Abstract
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OBJECTIVE: A loss of balance poststroke from externally induced-perturbations or during voluntary movements is often recovered by stepping. The purpose of this study was to characterize stepping behavior during lateral induced waist-pull perturbations and voluntary steps in community-dwelling fallers and nonfallers with chronic stroke.
METHODS: This study used a cohort design. Thirty participants > 6 months poststroke were exposed to 24 externally triggered lateral waist-pull perturbations and 20 voluntary steps. Balance-tolerance-limit (BTL) (transition from single to multiple steps) and first step type were determined for the waist-pull perturbations. Step parameters of initiation time, velocity, first step length, and clearance were calculated at and above BTL and for the voluntary steps. Hip abductor/adductor torque, foot cutaneous sensation, and self-reported falls that occurred 6 months prior were evaluated.
RESULTS: Twelve participants were classified retrospectively as fallers and 18 as nonfallers. Fallers had a reduced BTL and took more medial first steps than nonfallers. Above BTL, no between-group differences were found in medial steps. At BTL, the nonparetic step clearance was reduced in fallers. Above BTL, fallers took longer to initiate a paretic and nonparetic step and had a reduced nonparetic step length and clearance when compared with nonfallers. There was a between group difference in step initiation time for voluntary stepping with the paretic leg (P < .05). Fallers had a reduced paretic abductor torque and impaired paretic foot cutaneous sensation.
CONCLUSION: A high fall rate poststroke necessitates effective fall prevention strategies.Given that more differences were found during perturbation induced stepping between fallers and non-fallers, further research assessing perturbation induced training on reducing falls is needed.
IMPACT: Falls assessments should include both externally induced perturbations, along with voluntary movements in determining the fall risk.
Language: en |