An Innovative Concept for a Walker with a Self-Locking Mechanism Using a Single Mechanical Approach.

Background: The ageing process involves a natural degeneration of physiological function and can imply life constraints, namely during activities of daily life (ADL). Walking can be strongly affected by strength, gait, and balance changes, which affect quality of life. The quality of life of the older adult is associated with available solutions that contribute to an active and safe ageing process. Most of these solutions involve technical aids that should be adapted to older adults' conditions. Aim: To identify the advantages and disadvantages of two-wheeled walkers and of two different self-locking systems designed and developed by the authors. Methods: Two studies were performed based on the possible walker combinations used, using a walker with no wheels (classic fixed walker), a two-wheeled walker with self-locking mechanism made of gears and a spring (Approach 1), and a two-wheeled walker with a self-locking mechanism which uses a single spring (Approach 2). These combinations were tested in two quasi-experimental studies with pre-post test design. Results: No significant differences in duration, gait speed, and Expanded Timed Get Up and Go (ETGUG) were found between the walkers, but there was a marginally significant difference in Physiological Cost Index (PCIs), which means that the energetic cost with Approach 1 was greater than that with Approach 2. Users reported a feeling of insecurity and more weight, although no significant differences were observed and they were found to be equivalent in terms of safety. Study 2 found an improvement in duration and gait speed in the ETGUG between the different types of self-locking systems. Conclusions: The PCI is higher in the two-wheeled walker models and with the self-locking mechanism. Approach 2 did not show better conditions of use than the other two walkers, and participants did not highlight its braking system. Although safety is similar among the three walkers, further studies are needed, and the braking system of the two-wheeled walker needs to be improved (Approach 2).