After reading this post you will the following about Elbow joint:
- Type of joint.
- Bones participating in formation of shoulder joint and the articular surface.
- Attachment of capsule of joint.
- Ligaments supporting the joint.
- Muscles responsible for producing various movements.
- Applied aspect ofelbow joint.
Q. Describe elbow joint under the following headings:
a. Type b. Articular surfaces c. Fibrous Capsule d. ligaments e. Movements f. Relations g. Boold and nerve supply h.Applied aspect
A. Elbow joint
a. Type: It is a hinge variety of synovial joint. It is a compound joint as three bones take part in this articulation ( humerus, ulna and radius) .
b. Articular surfaces: Elbow joint consists of two articulations.
- Humero-ulnar articulation is between trochlea of humerus and trochlear notch of ulna
- Humero-radial articulation is between the capitulum of humerus and superior surface of head of radius.
c. Fibrous Capsule :
- It is lax and thin anteriorly to allow the flexion and extension movements and is strengthened on either side by the collateral ligaments.
- Above it is attached the medial epicondle, margins of coronoid, radial and olecronon fossa, and lateral epicondyle.
- Below it is attached to the anterior and medial margin of coronoid process and upper and medial margin of olecranon process of ulna, and annular ligament ( is nor attached to radius).
- Ulnar collateral ligament:
- Is triangular in shape.
- It extends from medial epicondyle of humerus to the upper end of ulna.
- It consists of three parts – anterior ,inferior and posterior.
- Superiorly: it is attached is to the medial epicondyle.
- Inferiorly: the anterior thick band is attached to the medial margin of coronoid process. The posterior band is attached to the medial margin of olecranon process and the inferior thich part of middle part extends from olecranon to coronoid process.
- It is related to the ulnar nerve.
- Radial collateral ligament:
- It extends from lateral epicondyle of humerus to the annular ligament.
|Movement||Muscles responsible for the movement|
|Brachioradialis ( in midprone position)|
- Anterior: Brachialis muscle and anterior to brachialis are- medial nerve, brachial artery and tendon of biceps brachii.
- Posterior: Triceps and anconeus.
- Lateral: Extensor carpi radialis brevis, supinator and common origin of extensors of forearm.
- Medial: Ulnar nerve, flexor carpi ulnaris and common origin of flexors of forearm.
g. Blood and nerve supply
- Blood Supply: by branches from arterial anastomosis around elbow which is formed by the branches of brachial, profunda brachii, ulnar and radial artery.
- Nerve Supply: By branches from musculocutaneous, medial, ulnar and radial nerves.
h. Applied Aspect
- Subluxation of head of radius/Pulled elbow: Occurs in children below 4 years when the forearm is is suddenly pulled in pronated position. The head of radius comes out of the annular ligament.
- Golfer’s elbow (medial epicondylitis): It occurs due to strain or tear of common flexor origin and inflammation of medial epicondyle. It is characterized by pain and tenderness over medial epicondyle.
- Tennis elbow ( lateral epicondylitis): It occurs due to strain or tear of common extensor origin and inflammation of lateral epicondyle. It is characterized by pain and tenderness over lateral epicondyle.
- Student’s elbow/Miner’s elbow: It occurs due to inflammation of subcutaneous olecranon bursa over the triangular subcutaneous bursa on posterior surface of olecranon process. it is characterized by painful swelling over the olecranon process.