The relationships between muscle strength, biomechanical functional moments and health-related quality of life in non-elite older adults

Abstract

Objective: to investigate the association between muscle strength, biomechanical functional moments during everyday tasks and health-related quality of life (HRQoL) in older adults.Methods: eighty-four healthy adults aged 60-88 years were tested. A torque dynamometer was utilised to measure muscle moments at the knee and hip joints. Functional assessment involved three-dimensional biomechanical analysis of gait, chair rise and sit-down, stair ascent and descent using an 8-camera VICON® system with Kistler force plates. HRQoL was assessed using the Short Form-36 (SF-36) questionnaire.Results: Spearman's correlation coefficient showed significant correlation (P < 0.001) between isometric strength and functional moments (r = 0.24-0.67). Muscle strength was significantly correlated with SF-36 scores, including physical functioning, bodily pain, vitality, social functioning and role emotional scores. Knee flexion moment was correlated with role physical, vitality, social functioning, role emotional, mental health and mental component scores (r = 0.24-0.40).Conclusion: loss of muscle strength is associated with poorer functional ability and both are associated with reduced HRQoL. The reduction in HRQoL is considerable in the physical functioning domain. Cause and effect was not established but studies need to be undertaken to evaluate the benefits of strength training, functional activity training or increased participation in life. © The Author 2011. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved.