Favourite Chairs - And the space in front- Pose a significant challenge for people at high risk of falling, therapists, designers and engineers

Introduction: People at high risk of falling, including people with Parkinson’s (PwP), tend to fall most frequently within their own homes, despite being highly sedentary. Unobtrusive sensors may soon be able to help people at risk, health professionals and researchers to understand more about where and how their home environment challenges people’s balance, to personalise fall risk reduction. We aimed to identify where PwP at high risk of falling most frequently lost their balance along the habitual route from their favourite chair to the staircase, to generate new data and guide future sensor studies. Methods: We video-recorded PwP at high risk of falling moving from their favourite chairs to their stairs at home, then two researchers collaboratively identified unstable transfers, walks, turns and stair ascents (near-misses) using ELAN annotation software. Results: We observed 13 PwP (median age 79 years; median 7 years post-diagnosis; Hoehn & Yahr 2.5 to 4) perform 82 chair-to-stair trials at home (median 5), a total of 575 actions (mean 7 actions per chair-to-stair trial). Fifty-four actions (9%) contained near-misses: 15/82 transfers (18%), 16/167 walks (10%), 19/244 turns (8%) and 4/82 stair ascents (5%). Two-thirds of near-misses (37/54, 69%) were in the living room, rather than the hall; half (28/54, 52%) happened rising or turning away from the chair. Ten of the twelve PwP who appeared unsteady anywhere (83%) nearly fell exiting their favourite chair. Conclusions: The concentration of near-misses around the favourite chair has implications for PwP, therapists, designers and engineers. As well as choosing a suitable chair (potentially one that rotates), the area directly in front of the chair needs to be kept clear to negate the need to turn during, or immediately on, rising. Exiting the favourite chair may be the most hazardous routine activity of someone sedentary or at high fall risk: clinical assessment elsewhere (using a standard chair) may be misleading, and using sensors to monitor genuine chair transfers far more informative.