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
Index finger Index finger The index finger (also referred to as forefinger, first finger, pointer finger, trigger finger, digitus secundus, digitus II, and many other terms), is the first finger and the second digit of a human hand. It is located between the first and third digits, between the thumb and the middle finger. It is usually the most dextrous and sensitive finger of the hand, though not the longest – it is shorter than the middle finger, and may be shorter or longer than the ring finger – see digit ratio. "Index finger" literally means "pointing finger", from the same Latin