Anatomical Review: The Elbow Joint

 A common injury seen at SquareOne Physiotherapy is lateral epicondylagia, or more commonly known as tennis elbow. The site of injury is at the lateral epicondyle, a bony bump on the outside of the elbow in which a group of muscles that extend the wrist and fingers attach to via a shared tendon. Overload of these muscles can lead to bony oedema of the lateral epicondyle and degenerative changes in the shared tendon which leads to pain and impairment. Treatment involves addressing the cause of the overload, soft tissue therapy to reduce the tension in the affected musculature, dry needling, taping and bracing, activity modification, rehabilitative exercises, and ice. Golfer’s elbow has the same pathological issues but occurs on the inside of the elbow as a result of overload to the muscles that flex the wrist and fingers. Most people with tennis and golfer’s elbow don’t play either sport!

 

The elbow joint is a complex hinge joint formed between the lower end of the humerus in the upper arm and the top ends of the ulna and radius in the forearm. The anatomical make up of the elbow allows for flexion and extension at the joint, as well as rotation of the forearm which is termed pronation and supination. Rotation is an important movement used for activities of daily living such as turning a key or a door handle. The range of motion of the elbow is limited by a bony prominence on the end of the ulna called the olecranon so that the elbow can only extend to around 180 degrees. Flexion of the elbow is limited by the compression of soft tissues surrounding the joint.

 A common injury seen at SquareOne Physiotherapy is lateral epicondylagia, or more commonly known as tennis elbow. The site of injury is at the lateral epicondyle, a bony bump on the outside of the elbow in which a group of muscles that extend the wrist and fingers attach to via a shared tendon. Overload of these muscles can lead to bony oedema of the lateral epicondyle and degenerative changes in the shared tendon which leads to pain and impairment. Treatment involves addressing the cause of the overload, soft tissue therapy to reduce the tension in the affected musculature, dry needling, taping and bracing, activity modification, rehabilitative exercises, and ice. Golfer’s elbow has the same pathological issues but occurs on the inside of the elbow as a result of overload to the muscles that flex the wrist and fingers. Most people with tennis and golfer’s elbow don’t play either sport!

 

The elbow joint is a complex hinge joint formed between the lower end of the humerus in the upper arm and the top ends of the ulna and radius in the forearm. The anatomical make up of the elbow allows for flexion and extension at the joint, as well as rotation of the forearm which is termed pronation and supination. Rotation is an important movement used for activities of daily living such as turning a key or a door handle. The range of motion of the elbow is limited by a bony prominence on the end of the ulna called the olecranon so that the elbow can only extend to around 180 degrees. Flexion of the elbow is limited by the compression of soft tissues surrounding the joint.

 

Like all other synovial joints, a thin layer of smooth joint cartilage covers the ends of the bones that form the elbow joint. The joint capsule of the elbow surrounds the joint to provide strength and lubrication to the elbow. Slick synovial fluid produced by the synovial membrane of the joint capsule fills the hollow space between the bones and lubricates the joint to reduce friction and wear.

An extensive network of ligaments surrounding the joint capsule helps the elbow joint maintain its stability and resist mechanical stresses. The radial and ulnar collateral ligaments connect and maintain the position of the radius and ulna relative to the epicondyles of the humerus. The annular ligament of the elbow extends around the head of the radius to hold the bones of the lower arm together. These ligaments allow for movement and stretching of the elbow while resisting dislocation of the bones.