Elbow Joint
The elbow joint is the hinge joint located in the center of the arm. It is a complex joint made up of three separate relationships; the humero-ulnar joint, the humeroradial joint and the superior radio-ulnar joint.
Each of these separate joints is comprised of two of the three bones of the arm; the humerus, the radius and the ulna. The bony projection at the rear of the joint, sometimes known as the funny bone, is the olecranon. The elbow joint is considered to be the most stable joint in the human body.
Function of the Elbow Joint
The elbow joint serves two functions for the human body. It allows for the flexion of the arm (bending and straightening) and allows the forearm to rotate into many complex positions. Without this joint, the arm would be almost functionless.
Elbow Joint Disease and Injury
While the elbow is considered the most stable joint in the body, it is not immune to disease and injury. Some of the more common types of injuries include dislocation, fracture, tendonitis and bursitis. Diseases of the elbow include arthritis and infection.
Elbow injuries and diseases generally affect athletes and extreme hobbyists, such as mountain climbers and body builders, due to the tendency of overuse of the elbow in repetitive motions.
Tendonitis, also known as tennis elbow and golfer’s elbow, is the inflammation of the tendons that surround the elbow joint due to overuse of the joint. Bursitis is caused by similar circumstances, but affects the bursa that surrounds the joint.
Elbow Rheumatoid Arthritis
A common type of arthritis seen in elbows is rheumatoid arthritis, a disease of the immune system causing the body’s white blood cells to attack and destroy the cartilage that covers the inside of the joint. Rheumatoid arthritis is a progressive disease, causing pain and limited range of motion as the cartilage that lubricates elbow movement is destroyed, causing painful friction between bones.
Elbow Osteoarthritis Arthritis
Another type of arthritis is osteoarthritis, which occurs after an injury or due to degenerative change over a number of years. The body reacts to an injury and surgery by forming scar tissue around the site. Scar tissue reduces the range of motion and causes stiffness and pain in the elbow joint, much like rheumatoid arthritis. People tend to use the elbow joint less, allowing for a deterioration of cartilage within the joint; thus making any subsequent movements more painful.
Elbow Joint Infections
Infections of the elbow joint are rare, but do occur. Some infections occur spontaneously with no known cause, or can be a direct result of a surgical introduction or secondary infection. Secondary infections occur when bacteria from a primary infection travels to another system in the body and multiplies.
The elbow joint is a very important joint within the human musculoskeletal system. It controls most of the motion of the arm and provides stability for both the shoulder and wrist. Care should be taken to prevent injury to this vital joint.
