Reach distance but not judgment error is associated with falls in older people

Reaching is a vital action requiring precise motor coordination and attempting to reach for objects that are too far away can destabilize balance and result in falls and injury. This could be particularly important for many elderly people with age-related loss of sensorimotor function and a reduced ability to recover balance. Here, we investigate the interaction between reaching ability, errors in judging reach, and the incidence of falling (retrospectively and prospectively) in a large cohort of older people.

Participants (n = 415, 70-90 years) had to estimate the furthest distance they could reach to retrieve a broomstick hanging in front of them. In an iterative dialog with the experimenter, the stick was moved until it was at the furthest distance they estimated to be reached successfully. At this point, participants were asked to attempt to retrieve the stick. Actual maximal reach was then measured. The difference between attempted reach and actual maximal reach provided a measure of judgment error. One-year retrospective fall rates were obtained at initial assessment and prospective falls were monitored by monthly calendar.

Participants with poor maximal reach attempted shorter reaches than those who had good reaching ability. Those with the best reaching ability most accurately judged their maximal reach, whereas poor performers were dichotomous and either underestimated or overestimated their reach with few judging exactly. Fall rates were significantly associated with reach distance but not with reach judgment error.

Maximal reach but not error in perceived reach is associated with falls in older people.