Figure 2.

Measuring sarcopenia, physical activity, and frailty. (A) A computed tomography cross section at vertebral level L3 with muscle highlighted in red, used for calculation of the SMI as square centimeters (cm²) of muscle area divided by the square of patient height (m²).4 Gender‐specific SMI cutoffs, 50 cm²/m² in men and 39 cm²/m² in women, are proposed to standardize sarcopenia measurement in liver transplant candidates.6 (B) Black arrowhead: a wearable personal activity monitor. Web‐based transmission delivers step count, heart rate, calories expended, and activity intensity to a user's smartphone and their electronic medical record.8 Red arrowhead: a dynamometer for measuring grip strength, a component of the LFI.9