Measurements of Muscle Mass, Equations and Cut-off Points

This chapter describes different methods that can be used to measure or estimate muscle mass. It discusses several sarcopenia cut-off points based on these methods. The chapter explains the estimation of muscle mass by anthropo metric methods such as arm and calf circumference as well as prediction equations based on anthropometric measures to predict appendicular skeletal muscle mass. Assessment of a single anthropometric measurement as well as a combination of anthropometric measurements have been used as indicators of skeletal muscle mass or have been used to predict skeletal muscle mass. The chapter describes the bioelectrical impedance method including the currently available muscle mass prediction equations. Bioelectrical impedance analysis prediction equations have been developed to estimate total or appendicular muscle mass. The chapter also describes the use of dual-energy X-ray absorptiometry and the use of the imaging techniques, computed tomography and magnetic resonance imaging.