Identification of kinetic differences between fallers and nonfallers in the elderly.

Abstract

Falls are a major cause of decreased mobility and disability in the elderly. Multiple factors are believed to contribute to falling. Among these, gait abnormalities have drawn attention as a possible risk factor. Although previous studies have revealed few differences in gait parameters compared with similar aged controls, it was hypothesized that because of intrinsic differences in balance and motor control, we would observe differences in joint kinetics. In this study, 15 subjects (mean age, 77 +/- 9 yr), who had at least 2 mo of repeated falls from an unclear cause, were evaluated in a gait laboratory and were compared with a control group of 15 subjects (mean age, 75 +/- 5 yr) with no history of falls. Analysis of data demonstrated a significantly greater peak torque in the falls group for the following: hip flexion, hip adduction, knee extension, knee varum, ankle dorsiflexion, and ankle eversion (P < 0.003 in each comparison). Also, ankle plantarflexion torque was significantly decreased in the falls group (P = 0.001). Joint powers showed different absorption at the knee and ankle in the falls group. The discovery of these kinetic differences may provide further insight into the mechanism of falls in the elderly and, more importantly, lead to identifiable markers to detect those who may be susceptible to falls.