The elbow is a hinged joint made up of three bones, the humerus, ulna, and radius. The ends of the bones are covered with cartilage. Cartilage has a rubbery consistency that allows the joints to slide easily against one another and absorb shock. The bones are held together with ligaments that form the joint capsule. The joint capsule is a fluid filled sac that surrounds and lubricates the joint. Show
 The important ligaments of the elbow are the medial collateral ligament (on the inside of the elbow) and the lateral collateral ligament (on the outside of the elbow.) Together these ligaments provide the main source of stability for the elbow, holding the humerus and the ulna tightly together. A third ligament, the annular ligament, holds the radial head tight against the ulna.
There are tendons in your elbow that attach muscle to bone. The important tendons of the elbow are the biceps tendon, which is attached the biceps muscle on the front of your arm, and the triceps tendon, which attaches the triceps muscle on the back of your arm. The muscles in your forearm cross the elbow and attach to the humerus. The outside (lateral) bump just above the elbow is called the lateral epicondyle. Most of the muscles that straighten the fingers and wrist come together and attach to the medial epicondyle, or the bump on the inside of your arm just above the elbow. These two tendons are important to understand because they are common locations of tendonitis. All of the nerves that travel down the arm pass across the elbow. Three main nerves begin together at the shoulder the radial nerve, the ulnar nerve and the medial nerve. These nerves are responsible for signaling your muscles to work and to also relay sensations such as touch, pain and temperature. NEXT TOPIC: Common Conditions that Require Elbow Arthroscopy Recommended textbook solutions
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Piazza: Introductory Italian2nd EditionDonatella Melucci, Elissa Tognozzi 809 solutions Points de Départ2nd EditionAlbert Valdman, Cathy Pons, Mary Ellen Scullen 376 solutions Deux mondes8th EditionBetsy Kerr, Guy Spielmann, Mary Rogers, Tracy D.Terrell 469 solutions Author: Niamh Gorman MSc • Reviewer: Francesca Salvador MSc The elbow joint is a synovial joint found in the upper limb between the arm and the forearm. It is the point of articulation of three bones: the humerus of the arm and the radius and the ulna of the forearm. The elbow joint is classified structurally as a synovial joint. It is also classified structurally as a compound joint, as there are two articulations in the joint. Synovial joints, also called diarthroses, are free movable joints. The articular surfaces of the bones at these joints are separated from each other by a layer of hyaline cartilage. Smooth movement at these joints is provided by a highly viscous synovial fluid, which acts as a lubricant. A fibrous capsule encloses the joint, and is lined internally by a synovial membrane. Synovial joints can be further categorized based on function. The elbow joint is functionally a hinge joint, allowing movement in only one plane (uniaxial). Key facts about the elbow joint
OsteologyThere are three bones that comprise the elbow joint:
These bones give rise to two joints:
The humeroulnar and the humeroradial joints are the joints that give the elbow its characteristic hinge like properties. The rounded surfaces of the trochlea and capitulum of the humerus rotate against the concave surfaces of the trochlear notch of the ulna and head of the radius. At the elbow joint, the proximal ends of the radius and ulna articulate with each other at the proximal radioulnar joint. Elbow joint with ligaments in cadaverThis joint, however, is considered to be a separate articulation than those forming the elbow joint itself. The proximal radioulnar joint is the articulation between the circumferential head of the radius and a fibro-osseous ring formed by the radial groove of the ulna and the annular ligament that hold the head of the radius in this groove. The proximal radioulnar joint is functionally a pivot joint, allowing a rotational movement of the radius on the ulna. MnemonicHere are is a mnemonic that can help you remember the articulations involved in the elbow joint. CRAzy TULips
Do you want some help in learning the elbow joint? The following study unit will teach you that topic in a fun and engaging way. Ligaments of the elbow jointThere are a collection of ligaments that connect the bones forming the elbow joint to each other, contributing to the stability of the joint. The humeroulnar and the humeroradial joints each have a ligament connecting the two bones involved at the articulation: the ulnar collateral and the radial collateral ligaments. The ulnar collateral ligament extends from the medial epicondyle of the humerus to the coronoid process of the ulna. It is triangular in shape, and is composed of three parts: an anterior, a posterior and an inferior band. The radial collateral ligament has a low attachment to the lateral epicondyle of the humerus. The distal fibres blend with the annular ligament that encloses the head of the radius, as well as with the fibres of the supinator and the extensor carpi radialis brevis muscles. The annular ligament also reinforces the joint by holding the radius and ulna together at their proximal articulation. The quadrate ligament is also present at this joint, and maintains constant tension during pronation and supination movements of the forearm. Looking for the easiest and most time efficient way to learn anatomy? Our anatomy quiz questions are your secret to success! Blood supply and innervationThe blood supply to the elbow joint is derived from a number of periarticular anastamoses that are formed by the collateral and recurrent branches of the brachial, profunda brachii, radial and ulnar arteries. Proximal to the elbow joint, the brachial artery, the largest in the arm, gives off two branches, a superior and inferior ulnar collateral artery. The profunda brachii gives off a radial collateral and a middle collateral artery. These pass towards the joint contributing to the anastomotic loop supplying the joint. Distal to the elbow joint, the radial artery gives off the radial recurrent artery, and the ulnar artery gives off the anterior and posterior ulnar recurrent arteries. These arteries ascend towards the elbow joint, anastamosing with the branches from the brachial and profunda brachii arteries in the arm. MovementsAs the elbow joint is a hinge joint, movement is in only one plane. The movements at the elbow joint involve movement of the forearm at the elbow joint. Flexion of the forearm at the elbow joint involves decreasing the angle between the forearm and the arm at the elbow joint. Extension involves increasing the angle between the arm and forearm. These movements are performed by two groups of muscles in the arm: the anterior compartment and the posterior compartment of the arm. FlexionMost of the muscles producing flexion are found in the anterior compartment of the arm. There are two muscles in this compartment that produce flexion at the elbow joint:
Both the biceps brachii and brachialis muscles are innervated by the Musculocutaneous nerve. While the biceps brachii and the brachialis muscles are the main flexors of the elbow joint, the brachioradialis muscle is also involved in flexion of the forearm at this joint. Brachioradialis originates for the lateral aspect of the distal humerus above the lateral epicondyle. It inserts onto the lateral aspect of the distal radius. Although this muscle is primarily in the forearm, it crosses the elbow joint so therefore it acts on the elbow joint. It is innervated by the radial nerve. MnemonicLearning the muscles that bend the elbow becomes child's play if you anchor them to a mnemonic like the one below. 3 B's bend the elbow
ExtensionExtension of the forearm at the elbow joint is the increase of the angle at the elbow to bring the forearm back to the anatomical position from a flexed position. There is one muscle involved in extension, the triceps brachii muscle. It is the only muscle in the posterior compartment of the arm. Triceps Brachii originates as three heads. The long head originates from the infraglenoid tubercle of the scapula, the lateral head originates from the lateral aspect of the humerus above the radial groove, and the medial head originates from the medial aspect of the humerus below the level of the radial groove. The three heads converge on a single tendon that inserts onto the olecranon of the ulna. It is supplied by the radial nerve, which passes down through the arm in the radial groove between the lateral and medial heads of the muscle. While flexion and extension are the only movements that can occur at the elbow joint itself, movement is also afforded at the proximal radioulnar joint, which contributes to the elbow joint. Movements at this joint are called pronation and supination. These are rotational movements that occur when the distal end of the radius moves over the distal end of the ulna by rotating the radius in the pivot joint formed by the circular head of the radius, the radial groove of the ulna and the annular ligament. Pronation and supination are easily visualised when the elbow is flexed at 90°. Supination is where the palm of the hand is facing upwards; pronation is rotation of the forearm so that the palm is facing downwards. In the anatomical position, the forearm is in the supine position. Pronation in the anatomical position is movement of the forearm so that the palm is facing posteriorly. Now that you've learned everything about the elbow joint, put that knowledge to the test with the following quiz! Clinical notesFracturesCommon injuries to the elbow joint include fractures of the bony structures contributing to the joint. Care must be taken when diagnosing a fracture of the elbow joint with respect to the age of the patient. This is because secondary ossification centres in children and adolescents can easily be mistaken for a fracture on a radiograph. Therefore, it is vital that a physician know the age of the child when examining their radiograph. Some of the areas of secondary ossification are as follows:
A supracondylar fracture is a fracture to the humerus above the level of the humeral condyles. This injury most commonly occurs in children. In such injuries, the distal bone fragment can be pulled posteriorly by the triceps muscle. This can cause bowstringing of the brachial arteries by stretching them, which can have adverse effects. Fracture of the head of the radius is a common fracture of the elbow joint. It is often caused by a fall on an outstretched hand, and can have severe implications including loss of full extension of the forearm at the elbow joint. Epicondylitis and arthritisEpicondylitis is inflammation of the soft tissues surrounding the epicondyles of the humerus. It typically occurs due to overuse of the flexor and extensor muscles of the forearm. Pain is localised around the epicondylar region. Tennis players typically get epicondylitis on the lateral epicondyle (common extensor origin), whereas golfers usually have it on the medial epicondyle (common flexor origin). Arthritis can occur at the elbow joint, and is usually more severe in the dominant limb of the patient. VenipuncturesAnterior to the elbow joint is a transitional zone between the arm and the forearm called the cubital fossa. Located in the subcutaneous tissue above the cubital fossa is a very superficial vein: the median cubital vein. This is a short vein connecting two longer superficial veins draining the upper limb, the cephalic and basilic veins, together. The medial cubital vein is one of the most common sites for venipuncture, which is collecting blood samples in the upper limb. SourcesAll content published on Kenhub is reviewed by medical and anatomy experts. The information we provide is grounded on academic literature and peer-reviewed research. Kenhub does not provide medical advice. You can learn more about our content creation and review standards by reading our content quality guidelines. References:
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Elbow joint: want to learn more about it? Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster. What do you prefer to learn with? “I would honestly say that Kenhub cut my study time in half.” – Read more. Is the elbow joint at the distal end of the humerus?Bones and Osteology
The elbow joint is composed of the distal end of the humerus and the proximal ends of the radius and the ulna (see the images below).
What bones form the elbow joint?Normal Anatomy of the Elbow. The arm in the human body is made up of three bones that join together to form a hinge joint called the elbow. The upper arm bone or humerus connects from the shoulder to the elbow forming the top of the hinge joint. The lower arm or forearm consists of two bones, the radius and the ulna.
What joint is at the end of the humerus?The glenohumeral (GH) joint is a true synovial ball-and-socket style diarthrodial joint that is responsible for connecting the upper extremity to the trunk. It is one of four joints that comprise the shoulder complex. This joint is formed from the combination of the humeral head and the glenoid fossa of the scapula.
What is the proximal end of the elbow?Structure. The olecranon is situated at the proximal end of the ulna, one of the two bones in the forearm.
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Part of the elbow is formed by the end of the humerus
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