An investigation of the effects of walking frame height and width on walking stability

Background: Walking aids are designed for structural support during walking, however, surprisingly self-reported use of a walking aid (“Yes, I use one.”) has been identified as a risk factor for falling. Adjustment and design of walking aids may affect their usefulness in facilitating a stable walking pattern. We previously identified that increased body weight transfer onto a walking frame (‘device loading’) is associated with increased user stability. Research question: We asked: “Could adjustment of walking frame height to a lower height than clinically recommended serve as a mechanism to facilitate device loading and thereby increase stability? And: “Do ultra-narrow frames have an adverse effect on stability as compared to standard-width frames? Methods: Ten older adults that were users of front-wheeled walking frames walked with walking frames of 1) ‘standard width, standard height’, 2)‘standard width, low height’, 3)‘narrow width, standard height’. Smart Walker technology was used to record forces acting on the walking frame and inside the user's shoes, and cameras recorded relative position of the user's feet in relation to the frame's feet. Stability of the user-frame system and device loading (percent body weight transferred onto the frame) were calculated. A general linear mixed effects model was used for statistical analysis. Results: A lower height setting did not increase device loading and stability, therefore adjusting the height to a lower setting proved to be an unsuccessful mechanism to increase stability. However, device loading was positively correlated with stability for all frame conditions (p < 0.05). Finally, stability was reduced when walking with the ultra-narrow, as compared to standard-width, frame (p = 0.002). Significance: To increase stability in fall-prone users, active encouragement to transfer body weight onto the walking frame is needed. Considering the adverse effects of ultra-narrow frames on stability, such frames should be prescribed and used with caution.