Mid-arm cross-sectional muscle area was studied in several domains to evaluate nutritional status and muscle area and hypertrophy in revalidation and strength-related studies. In this study, anthropometrically determined muscle + bone area formulas were validated against Houndsfield unit-based CT-scan measures at mid-humerus (stretched and relaxed), and mid-humerus -3 and -6 cm positions in 75 healthy male twins. Muscle + bone area estimates calculated by mid-arm circumference and the triceps skinfold (MBA.ANg, MBA.ANh) underestimated muscle area determined by CT imaging (MUS.CT) at all scans. The formula, including triceps and biceps skinfold (MBA.ANf), was in closer agreement with MUS.CT. It is therefore suggested that both the biceps and triceps skinfolds (or additional arm skinfolds) be used to estimate muscle area at the mid-arm position. The results emphasize the use of (nonremovable) landmarks in longitudinal studies that consider mid-arm muscle cross-sectional area, since the muscle area in three scans over a 6 cm region of the upper arm differs substantially and is in the same range as expected hypertrophic changes after short-term resistance training programs. Am. J. Hum. Biol. 9:73-86 © 1997 Wiley-Liss, Inc.
Copyright © 1997 Wiley-Liss, Inc.