The rollator is a mobility aid commonly used to facilitate balance and mobility for individuals with cardiorespiratory, musculoskeletal, or neurological deficits. Despite its popularity, there are also reports of adverse effects related to walker use linked to increased fall risks. Studies examining the effectiveness and consequences of rollator use have employed standard laboratory-based measurement methods that rely on performing specific tasks within a short time period and under controlled conditions, potentially limiting generalization to mobility in the everyday context. An instrumented rolling walker (iWalker) was developed as an ambulatory measurement tool applicable to the assessment of balance outside of the lab or clinic for assistive device users. The iWalker autonomously collects measurements of the upper and lower limb behaviour related to balance, walker kinematics, and video of the immediate spatial environment.

The design and development of the iWalker is first described, followed by two studies characterizing the involvement of the upper limbs for balance in standing and walking that served to address gaps in the literature and evaluate the utility of the upper limb measures. Overall, the upper limbs can become the primary effectors of balancing forces when lower limb capabilities are compromised. When lower limb involvement was experimentally constrained, the upper limbs became the primary effectors of balance control in healthy, young adults. In older adults, individuals demonstrating the highest upper limb usage during walking were associated with the largest reduction in frontal plane stepping parameters (i.e., step width). A third study evaluated the applicability of the iWalker to assess everyday mobility in a series of in-patients recovering from neurological injury (i.e., stroke, traumatic brain injury). Patients demonstrated significantly different upper limb balancing behaviour in everyday situations compared to in-laboratory assessments. Furthermore, the iWalker captured behaviours that may be precursors to falling, such as collisions, stumbling and lifting the assistive device. The implications of these studies on assessing the effectiveness of rollators and feasibility of using the iWalker in follow-up efforts are discussed.