An Approach to Assessment of the Fall Risk for the Elderly by Probe Reaction Time during Walking

Abstract

[Purpose] This study examined physical and cognitive factors associated with falls by the elderly. The authors hypothesized that, elderly people who experienced at least one fall in the past 12 months would show delayed probe reaction time (P-RT) during walking compared with elderly people with no history of falls. [Subjects] The subjects were 101 elderly people (27 males, 74 females), and the subjects were divided into two groups: a Fall group and a No-fall group. [Methods] We evaluated the probe reaction time, Trail Marking Test Part-A (TMT-A), Timed Up and Go Test (TUG), walking speeds at a self- determined pace, and the gait cycle time. [Results] The Fall group showed longer P-RT, TMT-A, TUG times and slower walking speeds than the No-fall group and its coefficient of variation (CV) of the time for a gait cycle was increased. In logistic regression analysis with fall as the dependent variable, the probe reaction time was identified as an significant factor, and the cut-off value of the probe reaction time was 406 ms as evaluated by the Receiver-Operating-Characteristic (ROC) curve. [Conclusion] It was found that probe reaction time is both reliable and useful for the evaluation of the fall risk for the elderly.