On the Movement Order of Four Limbs while walking and the Body Weight Distribution to Fore and Hind Limbs while Standing on all Fours in Monkeys

Abstract

Movement sequence of four limbs of monkeys while walking on all fours, as shown in Fig. 2, is quite different from that of most other mammals shown in Fig.1. These two different kinds of walking type were schematically illustrated and named by the authors in Figs 1 and 2 which show that each limb (LF-left fore limb, RF-right fore limb, LH-left hind limb. RH-right hind limb) moves one after another according to the arrows.In connection with this, the authors thought that there might be also some difference as to the body weight distribution to fore and hind limbs between monkeys and other mammals. As to many of non-primate mammals, it has been known that the body weight falls more heavily on the fore limbs than on the hind limbs, Therefore, the authors expected that the body weight of monkeys would fall more heavily on the hind limbs than on the fore limbs.Such an expectation was proved to be true by the following result which was gained by the authors on some of Japa nese monkeys (Macaca fuscata) standing still on all fours. The weight put on the floor by the fore limbs was about forty percent of the total body weight, while that by the hind limbs was about sixty percent. From the view point of the primate phylogeny, this result may suggest that the fore limbs of monkeys have a tendency to become free from body support or hind limbs have a tendency of stronger body supporting function.