Appendicular and mid-thigh lean mass are associated with muscle strength, physical performance, and dynamic balance in older persons at high risk of falls

Abstract

Background: Falls in older persons are associated with muscle mass and strength alterations, which may also affect balance parameters. However, the most appropriate combined approach to assess muscle and balance components that predict falls in older persons is still lacking.

Research question: We hypothesized that appendicular lean and/or mid-thigh mass and muscle strength and performance are positively associated with balance indices and fall risk in older persons.

Methods: Cross-sectional analyses of retrospective data from 260 participants with risk and/or history of falls examined at a Falls and Fracture Clinic. Assessments included a comprehensive clinical exam, bone densitometry and body composition by DXA, grip strength, gait speed, posturography, timed up and go (TUG) and four-square step (FSST) tests. Retrospective falls and fracture history was collected. Associations between appendicular and mid-thigh lean mass and muscle strength/performance vs balance indicators were determined before and after adjusting for age and gender.

Results: Mean age of participants was 78 ± 6.7 (65-96) years. Both appendicular and mid-thigh lean masses corrected for BMI (but not for height²), and muscle strength and performance measures are associated with better dynamic balance. Conversely, static balance indicators showed less consistent associations with lean mass. Only TUG and sit to stand time consistently showed significant associations with most static balance indicators.

Significance: Combined with strength and performance parameters, ALM and mid-thigh estimates adjusted by BMI strongly correlate with dynamic balance parameters and could become practical elements of falls risk assessment as well as markers of therapeutic response to falls prevention interventions.

Keywords: Balance; Falls; Mid-thigh; Muscle; Osteosarcopenia; Sarcopenia.