Leg Power and Velocity Predict the Risk of Major Osteoporotic Fractures (MOF): the Osteoporotic Fractures in Men (MrOS) Study.
Level 3 - non-randomized controlled study
Prospective longitudinal cohort study assessing baseline physical function metrics against incident clinical fracture outcomes over follow-up.
PubMed 41636594 · doi:10.1093/jbmr/zjag014
What was done
The study evaluated 1,841 older men (median age 84 years) enrolled in the Osteoporotic Fractures in Men (MrOS) study. Participants completed standing jump tests on a force plate to determine peak jump power (W/kg body weight), force at peak power (N/kg body weight), and velocity at peak power (m/s). Men excluded from performing the jump tests were classified into the lowest referent group (n = 599). Incident major osteoporotic fractures (MOF) were tracked via triannual questionnaires and confirmed by medical records. Multivariable Cox proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CIs) per standard deviation (SD) increment and across quartiles, with additional adjustment for femoral neck bone mineral density (FN BMD).
What was found
During 5 years of follow-up, 136 incident MOF occurred. In multivariable-adjusted models, each 1-SD increment in peak power was associated with a reduced risk of MOF (HR 0.71, 95% CI 0.54-0.92), and each 1-SD increment in velocity at peak power showed a similar association (HR 0.76, 95% CI 0.59-0.98). These associations remained significant after further adjustment for FN BMD. For force at peak power, only the highest quartile was associated with lower MOF risk, and this was no longer significant after adjusting for FN BMD.
Why it matters
Dynamic muscle power and movement velocity provide prognostic information for fracture risk beyond traditional muscle strength (force) and bone density. These findings suggest that interventions emphasizing movement speed and explosive power may be more relevant for fracture prevention than resistance training focused solely on maximal force generation.
Limits
The cohort included only older men (median age 84), limiting generalizability to women and younger populations. A large fraction of the cohort (599 of 1,841) was unable to complete the jump test and had to be assigned to a proxy referent group. The observational design cannot prove that training-induced increases in leg power or velocity directly reduce fracture incidence.
Cited by
- supports Accelerated loss of muscle power with aging (powerpenia) is strongly associated with fall risk, bone fractures, and joint dislocations, particularly after age 60 or 65.