Contribution of arm movements to balance recovery after tripping in older adults

Abstract

Falls are common in daily life, and our arms play an important role in recovering balance after a trip. Although older adults fall more often with more serious consequence, there is limited research into arm movements during falls in older adults. We investigated how older adults use their arms to recover from a trip and the difference between fallers and non-fallers. Sixteen older participants walked along a walkway and were occasionally tripped using a custom tripping device. A biomechanical model used full-body marker and force-plate data to calculate the body rotation during the trip, and simulated the rotation without arms (Cut) and with transfer of the arms momentum to the body (Transfer & Cut). We only analysed the first trip, distinguishing fallers (n=5) from non-fallers (n=11). Apart from an expected increase in forward body rotation at foot touchdown in fallers, we found no significant differences between fallers and non-fallers in the effects of arm movements on trip recovery. Like earlier studies in young participants, we found that arm movements had most favourable effect in the transversal plane: by delaying the transfer of angular momentum of the arms to the body, participants rotated the tripped leg more forward thereby allowing more room for a larger recovery step. Older adults that are prone to falling might improve their recovery from a trip by learning to [further] prolong ongoing arm movement.