Age-related differences in peak joint torques during the support phase of single-step recovery from a forward fall.

BACKGROUND: Previous studies have reported that older adults have a reduced ability to recover balance with a single step after a forward-induced fall. To better understand the reasons for this reduced ability, this study investigated any age-related differences in peak joint torques during the support phase of a single-step balance recovery from a forward fall.

METHODS: Ten young (19-23 years old) and 10 older (65-83 years old) men were released from forward-leaning positions and attempted to recover their balance with a single step. Lean was increased until they failed to recover their balance with a single step. Peak extensor torques were calculated for the support phase of balance recovery and were compared across age groups.

RESULTS: A consistent pattern of joint torques emerged during the support phase of balance recovery, suggesting a similar strategy across young and older participants. Despite this similarity, older participants exhibited smaller peak knee extensor torques during the support phase of single-step balance recoveries, and trends toward larger peak extensor torques at the hip and ankle.

CONCLUSIONS: The age-related differences found are believed to be the combined result of an age-related reduction in muscle strength and an age-related neuromuscular adaptation to mitigate the effects of muscle strength loss on physical performance capabilities.