Anterior thigh muscle thickness normalized by body mass index is associated with falls in community-dwelling adults

This study aimed to determine whether anterior thigh muscle thickness, normalized by height, weight, and Body Mass Index (BMI), is associated with falls in community-dwelling adults.

This cross-sectional study recruited community-dwelling adults aged ≥40 years living in Sado City, Niigata Prefecture, Japan. Anterior thigh muscle thickness (rectus femoris and vastus intermedius muscles) was measured using ultrasound and normalized by height², weight, and BMI. The primary outcome was self-reported falls in the past year, assessed via a questionnaire. Logistic regression analysis was conducted to examine the relationship between anterior thigh muscle thickness and falls, with age, sex, Mini-Mental State Examination (MMSE) score, grip strength, gait speed, fear of falling, comorbidities, and medications included as confounding factors.

A total of 310 participants (110 males, 200 females) were included in the analysis. The median age was 71.0 years for males and 67.0 years for females, with a BMI of 23.8 kg/m² for males and 22.5 kg/m² for females. The prevalence of falls in the past year was 15.5 %. Logistic regression analysis revealed that anterior thigh muscle thickness normalized by BMI was significantly associated with falls (OR 2.270, 95 % CI 1.130-4.550, p = 0.021) after adjusting for confounding factors. However, other adjustments were not significant.

Anterior thigh muscle thickness normalized by BMI was significantly associated with falls. Because this study was cross-sectional, causal relationships cannot be established. Thus, the association between anterior thigh muscle thickness and fall risk should be interpreted cautiously. Longitudinal studies are needed to confirm its predictive validity for future fall incidents.