The elbow is the joint connecting the proper arm to the forearm. It is marked on the upper limb by the medial and lateral epicondyles, and the olecranon process. Structurally, the joint is classed as a synovial joint, and functionally as a hinge joint. In this article, we shall look at the anatomy of the elbow joint; its articulating surfaces, movements, stability, and the clinical relevance. The elbow allows for the flexion and extension of the forearm relative to the upper arm, as well as rotation of the forearm and wrist. The specific structure of the elbow makes it simpler to diagnose fractures and different types of a painful anomaly, as well as to prescribe proper solutions, remedies and treatment. Here are all the things you need to know about the anatomy of the elbow…
Some preliminary basic information about the elbow joint
Like all other synovial joints, a thin layer of smooth articular 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 from the ulna 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. Being a hinge joint, the only movements allowed by the elbow are flexion and extension of the joint and rotation of the radius. The range of motion of the elbow is limited by the olecranon of the ulna, so that the elbow can only extend to around 180 degrees. Flexion of the elbow is limited only by the compression soft tissues surrounding the joint.
About the ligaments of the elbow joint
- Medial Collateral Ligament
Sometimes known as the Ulnar Collateral Ligament and consists of two triangular bands, anterior and posterior. Both sections arise from the Medial Epicondyle and pass over the inside of the elbow joint. The anterior portion then attaches to the front part of the top of the Ulna, known as the Coranoid process and the posterior part to the back of the Ulna, or Olecranon process.
- Lateral Collateral Ligament
Sometimes known as the Radial Collateral Ligament and is a short, narrow band which passes from the base of the Lateral Epicondlye to the Annular Ligament.
- Annular Ligament
This is a band of fibres which circle the head of the Radius, maintaining contact between the Radius and Humerus. Muscles and tendons – parts of the anatomy of the elbow-anatomy
Several muscles surround the elbow, making it possible for you to move your arm. The two main muscles responsible for bending and straightening the arm at the elbow are:
- triceps, located at the back of the arm
- biceps, located at the front of the arm
The main muscles of the elbow involved in wrist and finger movement are:
- flexors, which attach to the inside of the elbow and enable you to bend your wrists and fingers
- extensors, which attach to the outside of the elbow and enable you to extend or straighten your wrists and fingers.
Several tendons connect the muscles and bones of the elbow. The primary tendons are:
- biceps tendon, which attaches the biceps on the front of the arm to the radius, enabling you to forcefully bend your bend your elbow
- triceps tendon, which attaches the triceps to the ulna, enabling you to forcefully straighten your elbow .
Understanding the anatomy of the elbow let an ordinary person be prepared for the visitation to the doctor in case of in injury or some specific chronic joint disease. But medical examination is a must in all cases of an injury and pain regardless how well you understand the elbow anatomy.
Image of elbow anatomy , CC License