A type of primate locomotion which involves both forelimbs and the hindlimbs, although not to an equal extent. Some quadrupeds are hindlimb dominated, while the forelimb and the hindlimb are equally important to others.

There are several different kinds of quadrupedalism, as follows:
  • Branch running and walking, in which the animal walks along a branch grasping it with both their hands and feet.
  • Ground running and walking, in which the animal walks on the ground using both hands and feet, the plans of the hand flat on the ground.
  • Knuckle walking, a form of semi-quadrupedalism, found in chimpanzees and gorillas, in which the upper parts of the body are supported by the knuckles rather than the palms.
  • New World semibrachiation is a pattern involving using a prehensile tail in addition to the hands to suspend their bodies.
  • Old World semibrachiation is using the arms extending to grasp a branch, and commonly leaping.