Abstract
Using X-ray CT (computed tomography) images, the body composition of the area just 15 cm above the patella on the femoral region was studied in 60 humans (30 males and 30 females) . The total cross-sectional area, the each area of the subcutaneous fat, the muscle, the bone and the thickness of the fatty layer were measured and the each component was compared between the both sexes, and among the ages and the body types. The subjects were classified, by age, into five groups (under 19 years, 20-24 years, 25-29 years and over 30 years) and, by Rohrer Index, into three body types (A type; under 129, C type; 130-149 and D type; over 150) . 1) The total cross-sectional area in males were larger than in females, and the comparative studies of the each component of body composition revealed that the ratio of the muscular layer was larger in males than in females and that the thickness of the subcutaneous fat in females was about twice thicker than in males. In both sexes, the changes with the aging that were found to have occurred in the total cross-sectional area and the area of the muscular layer were similar. The comparative observation between the body composition and the body types showed that the total cross-sectional area, the area of the muscular layer and the fatty layer were the largest in D type, followed in order by the C type and the A type. 2) The subcutaneous fatty layer, measured at four sites (anterior, medial, posterior and lateral), was thicker in females than in males, and in both sexes, the medial position was the thickest and the lateral was the thinnest. In males, there was a more than twice difference in thickness between the medial position (thickest) and the lateral (thinnest), while in females, they had the mean values of the thickness within a comparatively narrow range. 3) Among the 11 muscles, vastus intermedius muscle showed the largest area in males, followed in order by adductor magnus muscle, vastus lateralis muscle, and biceps femoris muscle, while in females, vastus intermedius muscle had the largest area, followed in order by vastus lateralis muscle, adductor magnus muscle, and biceps femoris mucle. The changes of the muscle area with the aging that were observed to have occurred in vastus intermedius muscle and vastus lateralis muscle—the largest muscles in males—were similar to those in the muscular layer as a whole. The same was true in adductor magnus muscle, vastus medialis muscle and vastus lateralis muscle in females. As for the relation between the area of the muscular layer and the body types, in the muscles, which occupied the large percentage of the muscular layer, such as rectus femoris muscle, vastus intermedius muscle, vastus lateralis muscle and biceps femoris muscle in both sexes, and adductor magnus muscle in males, the area in the D type was largest, followed in order by the C type and the A type. 4) There were no significant changes in the bone area with the aging and the body types; however, the bone area was larger in males than in females in the each age and the body types.
