ACCURACY OF ANTHROPOMETRIC ESTIMATION OF MUSCLE CROSS-SECTIONAL AREA OF THE ARM IN MALES

Mid-arm cross-sectional muscle area was studied in several domains to evaluate nutritional status and muscle area and hypertrophy in revalid ation and strength-related studies. In this study, anthropometrically determined muscle + bone area formulas were validated against Houndsfi eld unit-based CT-scan measures at mid-humerus (stretched and relaxed) , and mid-humerus -3 and -6 cm positions in 75 healthy male twins. Mus cle + bone area estimates calculated by mid-arm circumference and the triceps skinfold (MBA.ANg, MBA.ANh) underestimated muscle area determi ned by CT imaging (MUS.CT) at all scans. The formula, including tricep s 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 mi d-arm position. The results emphasize the use of(nonremovable) landmar ks in longitudinal studies that consider mid-arm muscle cross-sectiona l 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. (C ) 1997 Wiley-Liss, Inc.