There are 3 separate joints that meet in the space commonly referred to as the elbow, with all of them sharing a single joint capsule. That complexity is what allows the elbow to bend and straighten and the forearm to rotate and thus the hand as well. This rotation is called supination and pronation, the same terms used to describe the side-to-side rotation of the foot controlled by the ankle joint. In the hand and arm, these movements are crucial to pulling, grabbing, throwing and pushing.
Inside the elbow joint, the humerus and the bones of the lower arm, called the radius and the ulna, not only hinge, but also rotate. In fact, the forearm bones actually cross over each other during pronation and supination. Yet the elbow is a small joint, not well padded, and unable to handle significant stress factors. Because the joint serves as a passageway for major arteries and nerves a dislocation or fracture can have serious consequences to mobility beyond mere damage to bones.
Take preventive measures to protect the elbow during activity. Use proper technique in all athletic motions; throwing, striking with a tennis racket, paddling, or rowing, for example, and be sure to engage the large muscles of the trunk, hips and legs. This takes the strain off the smaller elbow joint. Build, develop and increase strength by following exercises that maintain and grow the muscles and tendons that control the elbow joint. Since many of them also move the shoulder and wrist, make certain to employ a balanced conditioning program that includes all the muscles of the upper limbs. Alway wear safety gear when involved in sports where balance is an issue, such as inline skating, wear pads that protect the elbows and the wrists. Many elbow injuries occur as a result of landing on an unprotected wrist. Learn to fall properly when engaged in sports that involve the risk of falling. Consulting a coach, trainer or professional about learning how to fall properly, not on an outstretched hand, but by rolling backward over the scapula and then the shoulder, a maneuver known as the shoulder roll.
The multi-joint elbow region is the center point for much of the fine muscle coordination required in hand and arm movements. The humeroulnar joint, the elbow proper, is where the ulna of the forearm meets and hinges with the base of the humerus. The ulna runs along the forearm on the same side as the pinky finger. The humeroradial joint is the connecting point between the upper arm and the second bone of the forearm, the radius. These two bones attach at a point called the capitellum. The radius runs along the thumb side of the forearm. The proximal radioulnar joint joins the two forearm bones at the end closest to the elbow. The medial and lateral epicondyles are the knobs at the lower end of the upper arm. The muscles that extend the wrist attach to the lateral epicondyle, the knob on the outer part of your elbow, and the muscles that flex the wrist attach to the medial epicondyle, the knob at inner elbow.
The biceps brachii is the major muscle of the front part of the upper arm, they act to bend the elbow. It has two heads, one that crosses both the shoulder and the elbow and one that crosses just the elbow. The long head can act as a shoulder flexor as well as a flexor of the elbow. The triceps brachii is the three part muscle located at the back of the upper arm, it functions to extend or straighten the elbow.
The wrist flexors are the muscles that flex the wrist, pulling the palm of the hand toward the forearm. They are also capable of assisting the muscles of the upper arm with elbow flexion. These muscles cross the elbow and attach on the humerus at the medial epicondyle. The wrist extensors are the muscles that extend the wrist, lifting the back of the hand up toward the forearm. They are also capable of assisting the muscles of the upper arm with elbow flexion. These muscles cross the elbow and attach on the humerus at the lateral epicondyle. Attaching the humerus to the ulna, the ulnar, or medial, collateral ligament is a major contributor to the joints’s stability.
Nerves running through the elbow include the ulnar, radial and median nerves. The ulnar nerve is vulnerable to injury at the elbow because of its superficial location. It runs right along the medial epicondyle. Striking this area, also known as the funny bone, results in pain and tingling along the pathway of the nerve, down the forearm, and into the little finger. In addition to injury from repetitive stress, the elbow is susceptible to trauma that can damage the nerves running through this poorly padded region.