Abstract
The purpose of this study was to investigate the shape, the cross-sectional area (CSA), and the constitutive ratio of muscles in the thigh.
We studied nine healthy men and eight healthy women. We took measurements at various locations along the length of the thigh, giving the locations as a percentage of the thigh from the knee joint. The results showed that the maximum CSA of the muscles was at the 60% mark from the knee. Individual muscles showed a maximum CSA at different locations on the overall thigh: the sertorius was at 66.7%, the gracilis at 64.7%, the semimembranosus at 50.2%, the biceps femoris at 34.7%, the vastus lateralis at 67.1%, the vastus intermedius at 56.2%, the vastus medialis at 25.5%, the rectus fomoris at 67.5% and the adductors at 72.9%.
Looking at the constitutive ratio of muscles in the thigh, we found that the semimembranosus and vastus medialis are dominant in the distant thigh region, while the adductors are in the proximate thigh region. Also, between a distance of 20% and 80% from the knee, the quadriceps occupied about 50% of the total CSA. At a distance of 10% from the knee, the hamstrings occupied 52% of the total CSA.
From these results, we suggest that the characteristics of muscle shape and the constitutive ratio of muscles must be considered when evaluating the condition of a thigh.
