Characteristics of voluntary-induced stepping response in persons with stroke compared with those of healthy young and older adults

Background: Impairment of protective steps to recover balance from external perturbation isevident after stroke. Voluntary-induced stepping response (VSR) can be used to practiceprotective steps by instructing an individual to voluntarily lean their whole body forwarduntil they perceive a loss of balance and automatically induce a step. However, to improveprotective stepping performance, detailed characteristics of VSR in healthy persons arerequired.Research question: What is the difference in VSR between healthy and persons with stroke?Methods: An observational study was conducted in 30 participants, (10 young, 10 older, and10 persons with stroke). All participants performed VSR for 10 trials. Step length, step width,step duration, CoM position, CoM velocity, trunk-hip displacement, and strategies ofresponse were recorded using a motion capture system and analysed using Matlab software.Statistical analysis was performed using One-way ANOVA and Chi-square.Results: On average, participants with stroke had shorter step lengths and step durations thanyoung and older adults. Step width of older adults and participants with stroke was wider thanthat of young adults (p<0.05). While multiple steps and losing balance were reported morefrequently in participants with stroke than the others, the percentage of trials in whichparticipants grasped the handrails was not significantly different between older adults andparticipants with stroke. CoM position, CoM velocity, and trunk-hip displacement at footliftoff were significantly smaller in older adults and participants with stroke than youngadults (p