Formation of morphological traits of the quadriceps femoris muscle (QFM) before and after birth. Part I. Rectus femoris muscle (RFM).

Abstract

Studies on the formation of morphological traits of the quadriceps femoris muscle were carried out on the material of 138 human fetuses (70 males and 68 females), 9-36 weeks old, and 50 adults (33 male, and 17 female). Some intermediary conclusions were drawn for probable changes occurring in the morphological formation of the muscle after birth by comparing proportions of the muscle at the fetal stage with its form in adults. In this research, anthropometric methods and statistical analysis of results have been applied. The analysis of the results in the fetal group has shown that all metrical characteristics of the muscle reach their maximum values at the end of the investigated ontogenetic period. This is, naturally, a consequence of the development and growth of all fetal body measures, including an elongation of the thigh. Yet, the development of the individual muscle characteristics is not regular and although the trend of this growth is similar, its extent varies, and differs slightly in the two sexual groups. A comparison of the values of muscle indices for 9 month old fetuses with the same indices for adults shows that the relative dimensions of all investigated muscular characteristics decrease during the post-natal period except the relative length of the tendon.