Tendons are the connective tissues that link muscles to bones. They’re the conduits that transmit the force a muscle generates, allowing us to move.
The elbow is a complex joint, and its function relies on several tendons working in harmony. This joint allows you to flex, extend, pronate, and supinate your arm, thanks to the coordinated action of various muscles and their respective tendons.
This article explores the elbow tendons anatomy, their function, and their clinical significance.
Bones and Joints of the Elbow
The elbow is a complex joint where the bones of your upper arm connect to the bones of your forearm.
The bones of the elbow
- Humerus: The humerus is the bone in your upper arm. The end of the humerus connects to the radius and ulna in the forearm.
- Ulna: The ulna connects to the humerus to form the humeroulnar joint, which allows your forearm to flex and extend.
- Radius: The head of the radius connects to the humerus, allowing you to rotate your forearm so your palm is either up (supination) or down (pronation).
Joint Types
- Humeroulnar Joint: This hinge joint lets you flex and extend your forearm.
- Humeroradial Joint: In addition to flexion and extension, this joint allows for some rotation.
- Proximal Radioulnar Joint: This joint is key to rotating your forearm.
Major Elbow Tendons: Anatomy and Function
Many tendons cross the elbow joint, allowing you to bend, straighten, and rotate your forearm and wrist. Here’s a look at some of the most important.
Biceps Brachii Tendon
- Origin and Insertion: This tendon actually has two heads. It originates at the shoulder and inserts on the radial tuberosity, a bony prominence of the radius bone near the elbow.
- Function: The biceps brachii tendon is mainly responsible for bending the elbow and rotating the forearm so your palm faces up (supination).
- Clinical Relevance: The biceps tendon can rupture, which can weaken your ability to flex your elbow and supinate your forearm.
Triceps Brachii Tendon
- Origin and Insertion: The triceps brachii tendon originates from three heads and inserts onto the olecranon process of the ulna (the bony point of your elbow).
- Function: This tendon is mainly responsible for straightening your elbow (extension).
- Clinical Relevance: Triceps tendon injuries are less common than biceps injuries but can happen if you experience a direct blow to the elbow.
Common Extensor Tendon
- Origin and Insertion: This tendon originates from the lateral epicondyle of the humerus (the bony bump on the outside of your elbow) and connects to several wrist extensor muscles, including the extensor carpi radialis brevis.
- Function: This tendon facilitates wrist extension and stabilization.
- Clinical Relevance: This is the site of injury in tennis elbow (lateral epicondylitis), often due to overuse.
Common Flexor Tendon
- Origin and Insertion: This tendon originates from the medial epicondyle of the humerus (the bony bump on the inside of your elbow) and connects to several wrist flexor muscles, including the pronator teres.
- Function: This tendon allows you to flex your wrist and pronate (turn your palm down).
- Clinical Relevance: This is the site of injury in golfer’s elbow (medial epicondylitis), often due to overuse.
Ligaments Supporting the Elbow Joint
Several ligaments stabilize the elbow joint, including:
- Ulnar Collateral Ligament (UCL). The UCL, found on the inner side of your elbow, stabilizes the joint when stress is placed on it. Throwing athletes are prone to UCL injuries, sometimes requiring reconstructive surgery.
- Radial Collateral Ligament (RCL). The RCL, on the outer side of your elbow, stabilizes the joint when pressure is placed on it. It’s injured less often than the UCL, but can be damaged if the elbow is dislocated.
- Annular Ligament. The annular ligament surrounds the head of the radius, where it meets the ulna. It helps keep the elbow stable and aids pronation and supination.
Elbow tendon injuries
Elbow tendon injuries are common, especially among athletes and people whose jobs involve repetitive motions. Here are some of the most common tendon injuries that occur at the elbow.
Epicondylitis (tennis elbow and golfer’s elbow)
Tennis elbow and golfer’s elbow are both types of epicondylitis. With epicondylitis, the epicondyle (the bony part of your elbow) becomes inflamed.
- Lateral epicondylitis (tennis elbow) is an inflammation of the common extensor tendon on the lateral side of the elbow. It’s caused by repetitive wrist extension and overuse. If you have tennis elbow, you’ll likely have pain on the lateral side of your elbow that gets worse when you grip things.
- Medial epicondylitis (golfer’s elbow) is an inflammation of the common flexor tendon on the medial side of the elbow. It’s caused by repetitive wrist flexion and pronation. If you have golfer’s elbow, you’ll likely have pain on the medial side of your elbow that gets worse when you flex your wrist.
Tendon ruptures
- Biceps tendon rupture often occurs at the radial tuberosity insertion. It causes weakness in elbow flexion and supination and often requires surgery to repair.
- Triceps tendon rupture is less common, but it can happen at the olecranon insertion. It causes weakness in elbow extension and may need to be surgically repaired.
Bursitis
- Olecranon bursitis is an inflammation of the bursa that sits between the olecranon and the skin. It can be caused by trauma, infection, or repetitive pressure, and it results in swelling and pain at the tip of the elbow.
Frequently Asked Questions
What are the 4 major ligaments of the elbow?
The elbow’s stability relies on four key ligaments. There’s the ulnar collateral ligament (UCL), essential for resisting valgus stress (outward bending). The radial collateral ligament (RCL) resists varus stress (inward bending). The annular ligament stabilizes the radius bone in the elbow joint, and the quadrate ligament reinforces the joint capsule.
What are the major tendons in the elbow?
Several tendons are crucial for elbow function. The biceps tendon attaches the biceps muscle to the radius, enabling elbow flexion and supination. The triceps tendon connects the triceps muscle to the ulna, responsible for elbow extension. The common flexor tendon attaches forearm flexor muscles to the medial epicondyle, while the common extensor tendon attaches forearm extensor muscles to the lateral epicondyle.
How to tell if a tendon is torn in the elbow?
Signs of a torn elbow tendon vary depending on the tendon affected. Generally, you might experience sudden, sharp pain in the elbow, often accompanied by a popping or tearing sensation. Weakness when bending or straightening the elbow, difficulty gripping objects, swelling, bruising, and tenderness around the elbow joint are also common indicators. See a doctor if you suspect a tear.
Final Thoughts
The biceps, triceps, common flexor, and common extensor tendons all play a crucial role in the movement of your elbow.
Understanding the anatomy of these tendons, as well as the ligaments and surrounding structures, is essential for diagnosing and treating common elbow injuries. It’s also important for managing elbow pain and dysfunction effectively.
To keep your elbows healthy, prevention is key, as is proper rehabilitation if you do experience an injury.