Identifying predictors of upper extremity muscle elasticity with healthy aging

Advanced age influences muscle fiber composition and can potentially lead to declines upper extremity function. Ultrasound shear wave elastography provides direct measures of muscle mechanics, providing new insights into how both biological age and function influence muscle stiffness. The current study explored how the passive elastic properties of five upper extremity muscles relate to posture, biological age, sex, body mass index, and clinical measures of upper extremity function. Our results indicate humeral elevation and functional clinical measures are better predictors of muscle elasticity than biological age.