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
Ulnar collateral ligament injury of the elbow injury. During the cocking phase of pitching, the shoulder is horizontally abducted, externally rotated and the elbow is flexed. There is slight stress on the UCL in this position but it increases when the shoulder is further externally rotated. The greater the stress the more the UCL is stretched causing strain. During the overhead throwing motion, valgus stress on the medial elbow occurs during arm cocking and acceleration. The initiation of valgus stress occurs at the conclusion of the arm-cocking phase. In the transitional moment from arm cocking to arm acceleration, the shoulder vigorously rotates internally, the forearm is in