A generalizable methodology for stability assessment of walking aid users

Costamagna, E

Abstract

Walking aids (WAs) aim to improve stability and are used by up to 50% of older Europeans. Paradoxically, their use has been linked to a 2-3-fold increase in the risk of falling. The reasons of this association are unknown, indeed WA use remains poorly understood as clinicians have no objective assessment method to identify how stable a person is with a particular WA. This gap in the knowledge base justifies further research into what constitutes stable/safe use of WAs.
This PhD presents the development and demonstration of a novel approach to the assessment of stability of WA users. The approach used introduces the concept of the combined Stability Margin, which considers the user and their walking aid as a single combined system and provides an indication of how close the system is to “tipping-over” and, hence, falling. To calculate the combined Stability Margin, the Salford Walking Aid System (SWAS) was developed, which comprises force sensors (one in each WA leg), two pressure-sensing insoles, infrared cameras, and custom-written software. The approach was implemented for three different WAs: a pick-up Zimmer frame, a rollator, and, towards the end of the PhD, a front-wheeled Zimmer frame.
The SWAS allow for investigation of the combined Stability Margin in relation to key factors such as movement patterns, activity type, device loading, and environment. Results show that stability is reduced during performance of complex tasks such as turning or stepping up a kerb as compared to straight line walking and that the strategy used to perform a given task also affects stability.
Furthermore, the combined Stability Margin depends on user-specific factors such as the amount of body weight transferred onto the device, suggesting that absolute values of the combined Stability Margin may not provide a comprehensive measure of stability. Hence, additional analyses are undertaken to explore how the combined Stability Margin can be used to distinguish between more and less stable users and inform on the most appropriate type of walking aid for a given user.
Longer term, this research provides the foundations for future prospective falls studies, focusing on the role of walking aids in falls and provides a basis for more informed WA prescription and user training.

Citation

Costamagna, E. (in press). A generalizable methodology for stability assessment of walking aid users. (Thesis). University of Salford

• Thesis Type: Thesis
• Acceptance Date: Sep 28, 2018
• Deposit Date: Oct 2, 2018
• Publicly Available Date: Oct 2, 2018
• Related Public URLs: https://usir.salford.ac.uk/42571/
• Award Date: Sep 17, 2018