What Is the Intermembral Index of Chimpanzees?

The intermembral index for a chimpanzee is 106 to the 12th degree whereas the intermembral index for a human is 88 to the 11th degree. The intermembral index is a ratio of limb proportions that provides insight into the type of locomotion of an animal.

The intermembral index is calculated by dividing the length of the forearm, running from the humerus to the radius, by the length of the hind leg, running from the femur to the tibia. A high intermembral index indicates that the primate relies primarily on its forelimbs for climbing and swinging, whereas a low intermembral index indicates primary use of the hind legs for bipedalism, notes eFossils.