Knuckle transition is defined as the movement of the African gorillas, and chimpanzees on all four feet, in which the front extremities are placed at the back of the middle phalanx.

The occasionally observed walking upright in these apes, however, a rather rare form of locomotion.

A comparison of the wrist bones of chimpanzees and gorillas revealed that their knuckle-walking is independently developed, that their last common ancestor that is not yet had this running posture. It was concluded that the Hominini - also descended from ancestors with no knuckle-walking - the types of people leading to the development line.