Anthropometric estimation of muscle mass in men

Twelve male cadavers (aged 50-94 yr) were subjected to comprehensive anthropometry, dissection, and weighing of all skeletal muscle. Correlation coefficients of limb girths with total skeletal muscle mass (MM) were high: forearm r = 0.96, mid-thigh r = 0.94, calf r = 0.84, and midarm r = 0.82. These increased when limb girths were corrected (by subtracting pi times the skinfold thickness) to estimate muscle girth. For dimensional consistency, variables in the regression analyses included the product of stature and the square of each corrected girth. For the six unembalmed cadavers, this yielded a three-girth equation for MM (r2 = 0.93; SEE = 1.56 kg), which was then validated using data from the embalmed cadavers. It predicted MM with an SEE of 1.58 kg and r2 = 0.93. Because the values of these SEEs were similar, we pooled the subjects from the two groups to generate the final estimation equation: MM = STAT (0.0553CTG2 + 0.0987FG2 + 0.0331CCG2) - 2445 (SEE = 1.53 kg, r2 = 0.97), where STAT is stature (cm), CTG is thigh circumference corrected for the front thigh skinfold thickness (cm), FG is the uncorrected forearm circumference (cm), and CCG is the calf circumference corrected for the medial calf skinfold thickness (cm). Despite the limitations of the cadaver sample, the proposed equation appears to provide the best estimate of skeletal muscle mass to date, in that it is the only cadaver-validated equation and it gives values that are consistent with all known dissection data.