which forearm bone(s) contribute(s) most heavily to the elbow joint?which forearm bone(s) contribute(s) most heavily to the elbow joint?
An inside look at the structure of the elbow. #. Advertisement. Advertisement. The elbow is where the two bones of the forearm â the radius on the thumb side of the arm and the ulna on the pinky finger side â meet the bone of the upper arm -- the humerus. The lower end of the humerus flares out into two rounded protrusions called epicondyles, where muscles attach.