Researcher(s)
- Sophia Burrowes, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- Jill Higginson, Mechanical Engineering, University of Delaware
Abstract
Up to 80% of stroke survivors have low mobility and weak muscle groups causing a slower gait speed along with lower propulsion compared to healthy individuals.
For stroke rehabilitation, a couple tools used are split-belt treadmills which have two belts such that each leg walks at different speeds and visual feedback which have been shown to increase propulsion on split-belt treadmills.
We have developed an adaptive split-belt treadmill (sATM) that targets unilateral propulsion. Combining these tools has not been investigated deeply. In this study, we observed the effect of biofeedback on how participants walked on an sATM. We hypothesized that biofeedback would increase propulsion.
Four young healthy participants participated in the study. Participants first performed two familiarization trials on the Tied adaptive treadmill (ATM) and then with visual feedback on the sATM. They then performed one Tied and four randomized trials on the sATM. The speed of the Tied ATM updated at every step based on user gait mechanics. The belt speed on the sATM updated independently based on that leg propulsion and position on the treadmill. The propulsion gain on an assigned side was varied for the sATM – Equal, Low, Medium, and High to impose an increased propulsion demand. Visual feedback of the belt speed difference was displayed with a target (bounds = ± 0.1 m/s).
The peak AGRF for the assigned side was calculated. Trials with over 70% cross-over- when the leg contacts both belts instead of one, were excluded from analysis. For all for participants, the effect size ω2from the ANOVA was relatively small (-0.0055). Without biofeedback, the effect size ω^2 was moderate (0.22). Success scores were calculated and two participants who scored less than 50% in sATM trials were excluded from the analysis. After excluding them, the effect size ω^2 for peak AGRF was high (0.72).
This study found that there was almost no effect of including biofeedback; however looking at the first two participants, there is a large effect on propulsion which suggests that biofeedback changes peak propulsion. Visual feedback and a split-belt treadmill may change gait mechanics which means participants’ paretic side increased propulsion. This may increase peak AGRF in clinical populations such as stroke.