Functional Performance And Fall Risk Prediction With Different Muscle Quality Indices

Age-related declines in muscle quality (sarcopenia) lead to reduced functional health and increased fall risk. Evaluating muscle quality using a multifactorial approach can provide clinicians with a more comprehensive assessment of aging adults’ health and fall risk. PURPOSE: Identify which muscle quality index best predicts functional health and fall risk classifications. METHODS: Twenty-four participants (66 ± 10 yrs) completed total-body Dual-energy X-ray Absorptiometry scans for muscle mass (LM kg) and ultrasound imaging of the biceps brachii and vastus lateralis for muscle quality (echogenicity) assessments. Participants also completed 30-second sit-to-stand (30STS), timed-up-and-go (TUG), five sit-to-stand (5STS), 10-meter walk (10MWT), hand grip, back scratch (BS), Sit-n-Reach, and six balance poses. Participants were considered at elevated fall risk based on their 30STS scores per CDC guidelines. Lastly, upper- and lower-body functional muscle quality were computed by dividing mean hand grip by mean arm lean mass (UMQI) and Watts, calculated during the 5STS, by mean leg lean mass (LMQI). Statistical analyses included bivariate correlations and linear and logistic regressions to assess muscle quality indices' associations and predictive power on functional health and fall risk; all α ≤ 0.05. RESULTS: LMQI significantly predicted 30STS, TUG, 10MWT, and gait speed (R2 = 0.419-0.733; p ≤ 0.001), while echogenicity and UMQI did not. Further, every one-unit increase in LMQI was associated with a 94.5% decrease in the odds of being classified as high-risk for falls (R2N = 0.426; p = 0.004; Figure 1). CONCLUSION: This study found that LMQI was the greatest predictor of functional health in aging adults and predicted fall risk classification categories. This supports the current emphasis for sarcopenic assessments to include both muscle function and mass, which may offer clinicians a more accurate assertion of health and fall risk in aging adults. Supported by: This research was funded by Central States American College of Sports Medicine