The effects of ageing on functional capacity and stretch-shortening cycle muscle power

[Purpose] To examine the effects of age and gender in an ageing population with respect to functional decline and the relationship between muscle power and functional capacity. [Participants and Methods] The cohort (N=154) was subdivided into youngest-old (65-70 years.; n=62), middle-old (71-75 years.; n=46), and oldest-old (76-81 years.; n=46). Measures of mechanical muscle function included countermovement jump height, muscle power, leg strength and grip strength. Functional performance-based measures included heel-rise, postural balance, Timed Up and Go, and gait speed. [Results] The oldest-old performed significantly worse than the middle-old, whereas the youngest-old did not outperform the middle-old to the same extent. Increased contribution of muscle power was observed with increasing age. Males had consistently higher scores in measures of mechanical muscle function, whereas no gender differences were observed for functional capacity. [Conclusion] The age-related decline in functional capacity appears to accelerate when approaching 80 years of age and lower limb muscle power seems to contribute to a greater extent to the preservation of functional balance and gait capacity at that stage. Males outperform females in measures of mechanical muscle function independent of age, while the findings give no support for the existence of gender differences in functional capacity.