Which neuromuscular attributes are most associated with mobility among older primary care patients?

Objective: To identify the neuromuscular attributes that are associated with self-reported mobility status among older primary care patients.

Design: Cohort study.

Setting: Metropolitan-based health care system.

Participants: Community-dwelling primary care patients aged ≥65 years (N=430), with self-reported modification of mobility tasks resulting from underlying health conditions.

Interventions: Not applicable.

Main outcome measures: Basic and Advanced Lower Extremity Function as measured by the Late Life Function and Disability Instrument.

Results: We constructed multivariable linear regression models evaluating both outcomes. For Basic Lower Extremity Function, leg strength, leg velocity, trunk extensor muscle endurance, and ankle range of motion (ROM) were statistically significant predictors (P<.001, R(2)=.21). For Advanced Lower Extremity Function, leg strength, leg strength asymmetry, leg velocity, trunk extensor muscle endurance, and knee flexion ROM were statistically significant predictors (P<.001, R(2)=.39). Sensitivity analyses conducted using multiple imputations to account for missing data confirmed these findings.

Conclusions: This analysis highlights the relevance and importance of 5 categories of neuromuscular attributes: strength, speed of movement, ROM, asymmetry, and trunk stability. It identifies novel attributes (leg velocity and trunk extensor muscle endurance) relevant to mobility and highlights that impairment profiles vary by the level of mobility assessed. These findings will inform the design of more thorough and potentially more effective disability prevention strategies.