BIOMECHANICAL FORCES ACTING ON ELBOW( A STATIC ANALYSIS) Essay

BIOMECHANICAL FORCES ACTING ON ELBOW( A STATIC ANALYSIS) - Essay Example Meanwhile, a force is an effect on a certain body which changes its shape or motion. The elbow transforms shearing, compressional, and rotational forces into a normal motion. During flexion, the arm is bent, the pressure forces that moves along the elbow joint shift forces from the humerus to the ulna. Under extension, on the contrary, the applied forces run along the radius and the humerus, with the arm straightly open. The elbow displaces such forces largely through the muscles and ligaments that absorb and disperse stresses. Since the surface area of the ulna is bigger than that of the radial head, the ulna contributes lesser force per unit area as compared to the humerus. In addition, to avoid bone strain absorption, the elbow articular cartilages acts as a buffer between the bones. In the event that the cartilage is forced to absorb great stress for various times, the stress flattens out the cartilage and will eventually result to early wearing. Basically, the elbow is considered as a hinge joint with a single degree of freedom. However, its anatomical structure necessitates the inclusion of the articulations along with the radius and ulna. Thus, the elbow is best treated as having a mechanism of a two degree freedom that supports the supination/pronation of the forearm and the extension/flexion of the elbow. In terms of internal structure, the three synovial joints, along with subtle interactions, are radio-ulnar, humero-ulnar, and humero-radial. The humero-radial joint is of prime interest because of the combination of relative motions that occur therein: the axial rotation that involves in the forearm supination/pronation and the elbow flexion accompanying the ulna (Lockard 2006, p. 72). Flexion/extension moments are produced by the muscles that act over the elbow join, including brachioradialis, brachialis, triceps, and biceps brachii. While pronation is achieved through the muscles in the forearm, pronator quadratus,