This proof-of-concept study aims to examine the immediate effects of a semi-assistive fall controllable device, featuring BOS expansion and LMPT adjustment, on lateral stability and the muscle activity of ankle invertors and evertors that contribute to lateral stability.
Seventeen healthy adults, aged 20–25 years, participated in the study. Gait was measured on a laterally inclined walkway to simulate a high-demand task for lateral stability under three conditions: (1) without IFO, (2) with IFO, BOS only, (3) with IFO, BOS and LMPT.
Gait analysis was conducted using a 3D motion capture system and a force plate to measure and calculate the mediolateral center of gravity-center of pressure inclination angle (ML COG-COP IA) as an indicator of lateral stability. Additionally, muscle activity during the stance phase was analyzed. Surface electromyography data from tibialis anterior (TA), peroneus longus (PL) and soleus (Sol) were bandpass filtered, with root mean square values normalized to %MVC for comparison. A one-way repeated measures ANOVA was performed to examine differences among the three conditions, followed by a Bonferroni post-hoc test for multiple comparisons. The significance level was set at p 0.05.
A one-way repeated measures ANOVA for ML COG-COP IA showed a statistically significant difference among conditions (F = 6.581, p = 0.004). Post-hoc comparisons revealed significant differences in mean ML COG-COP IA between condition 1 and condition 3 (p = 0.014, 95% CI: [−0.383, −0.039]) and between condition 2 and condition 3 (p = 0.022, 95% CI: [−0.458, −0.031]). However, no statistically significant differences were found in the muscle activity of the TA, PL, and Sol across all conditions (p > 0.05).
This proof-of-concept study demonstrated the immediate effects of the IFO as a semi-assistive fall-controllable device that incorporates BOS and LMPT mechanisms. The results indicated that this mechanical intervention provided immediate improvements in lateral stability during gait in healthy individuals, suggesting that the stabilizing effects were achieved without significantly increasing the muscle activity of the TA, PL, and Sol.
This study introduces a novel Assistive Technology (AT) to improve lateral stability during gait, addressing current limitations. The findings lay a foundation for future fall-prevention AT systems. However, further clinical trials in high-risk populations are needed. It also emphasizes physiotherapists' roles in interdisciplinary collaborations for advancing practical fall prevention technologies.
Fall prevention
Lateral stability
