On the Morphological and Functional Laterality in Human Extremities, Especially in the Lower Limb.

In the present paper, the morphological, and functional laterality in human extremities was considered based on two kinds of investigation ; a questionnaire one on the handedness and footedness in 272 students of a woman college of physical education, and an experimental one of somatological measurements and functions in each eight right and left handed subjects of them.According to the questionnaire investigation the followings were found; In the upper limb, the conscious handed side takes an initiative role for the movement and the action. However, in the lower limb, the opposite side to the handedness seems to take a supporting role and the same side to take a functional one, respectively.On the other hand, according to the morphological and functional experiment, both the upper and lower limbs showed morphologically and functionally an asymmetry, which was more considerable in the subcutaneous fat thickness and various functions, followed by the breadth of joints and the greatest girth than in the length of limb. That is, the differentiation of laterality seems to be more apparent in the soft tissues than in the skeleton, and functionally than morphologically. In the upper limb, the laterality was generally recognized in the same side of the handedness. In the lower limb, the same sided laterality with the handedness was observed in the measurements of lower thigh and foot, the strength of flexion and extension at the knee joint and the reaction time of the action of ankle joint. The opposite sided laterality to the handedness seen in the subcutaneous fat thickness also assured the same sided laterality of the function in lower limb to the handedness. At the same time, the lower limb seemed to show the opposite sided laterality to the handedness in the cooperative movement and action with the upper limb. That is, in the lower limb, the initiative laterality (the fo-otedness) seemed to be at the same side to the handedness.