Ankle Muscle Power and Balance Performance in Older Adults

Purpose: This cross-sectional descriptive study sought to determine the influence of ankle power on balance performance. Method: Twenty healthy older adults (≥ 70 years; 11 men, 9 women; mean age of 76.6 [SD 5.5] years) with no prior debilitating injuries, neurological disorders, or respiratory diseases participated. Ambulatory balance was assessed using the Community Balance and Mobility Scale (CB&M, out of 96) - a performance-based functional outcome measure. Average power about the ankle joint was measured during unilateral isotonic ankle plantarflexion and dorsiflexion contractions. The Gait Real-Time Analysis Interactive Lab (GRAIL) system was used for perturbation tests, which included posteriorly directed movements of treadmill belts (300 ms duration, causing an anterior displacement of the participant's centre of mass) performed unilaterally (left belt) or bilaterally (both belts). The relationship between the average power measured at the ankle joint and balance performance was assessed. Results: Older adults demonstrated a significant positive correlation between ankle plantarflexor power and CB&M score (ρ = 0.464; p = 0.04) and between ankle plantarflexor power and unilateral perturbation intensity (ρ = 0.486; p = 0.03). Conclusion: Maintaining ankle plantarflexion power during the aging process may be critical in maintenance of functional performance in older adults.