Are jumping mechanography assessed muscle force and power, and traditional physical capability measures associated with falls in older adults? Results from the Hertfordshire Cohort Study

OBJECTIVES: To explore associations between measures of lower limb muscle force, velocity and power from jumping mechanography (JM) and simple physical capability (PC) testing, and falls in community dwelling older adults. METHODS: Participants performed a two-leg countermovement jump on a ground reaction force platform. Jump force, power and velocity were calculated. PC tests were 6m timed-up-and-go (TUG)(sec), grip strength (kg), gait speed (m/s) and chair rise time (secs). Two-three years after JM and PC testing, self-reported falls in the previous year were recorded, and logistic regression analysis used to determine whether JM and PC measures were associated with falls. RESULTS: Fall and PC data were available for 258 (169 JM) participants. Mean (SD) age at baseline was 75(2.5) years, 50% (n=129) were women and 27% (n=70) had fallen. As power and velocity increased, the odds of being a faller decreased [(odds ratio (OR)=0.91, 95% confidence interval (CI) 0.85,0.98] and (OR=0.20, 95% CI 0.05 0.72) respectively). Whilst grip strength and TUG were associated with falling; relationships were attenuated after adjustment. CONCLUSIONS: Jumping mechanography-measured muscle power and velocity were associated with lower risk of falls. In this relatively healthy cohort of older adults JM appears to be more sensitive measure of muscle deficits and falls risk than standard PC measures.