Elbow taken as six handbreadths; three to the elbow and three from the elbow to the shoulder. Another measure was the "cubit" (from "cubital"). This was taken to be the length of a man's arm from the elbow to the end of the middle finger. Though the elbow is similarly adapted for stability through a wide range of pronation-supination and flexion-extension in all apes, there are some minor differences. In arboreal apes such as orangutans, the large forearm muscles originating on the epicondyles of the humerus generate significant transverse forces on the elbow joint. The structure to resist these forces is
Bird measurement toes which is often marked by a difference in the scalation is used as a standard measure. In most cases the tarsus is held bent but in some cases the measurement may be made of the length of this bone as visible on the outer side of the bend to the base of the toes. In the case of cranes and bustards, the length of the tarsus is often measured along with the length of the longest toe to the tip of the claw. The measurement of the tail is taken from the base of the tail to the tip