Elbow Joint Anatomy - Bony Landmarks

Elbow Joint Anatomy - Bony Landmarks

• The olecranon is the prominent bony projection on the posterior aspect of the elbow.
• It's palpable when the elbow is flexed and the forearm is in neutral.
• It divides the flexor muscles from the extensor muscles and can be traced distally to the ulnar styloid process.
• The medial epicondyle is a large, prominent bony projection on the medial aspect of the elbow.
• It's located on the ventral surface and can be palpated easily.
• The lateral epicondyle is a smaller, more rounded bony projection on the lateral aspect of the elbow.
• The capitulum of the humerus is a rounded, convex bony structure situated just distal to the lateral epicondyle.
• It can be palpated with pronation and supination of the forearm, as it remains stationary.
• The radial head is a convex bony structure that articulates with the capitulum and the radial notch of the ulna.
• It can be palpated just distal to the capitulum and moves with pronation and supination.

Elbow Joint Muscles and Tendons

• The triceps brachii muscle is the main extensor of the elbow joint.
• It's located on the posterior aspect of the arm.
• The tendon of the triceps can be palpated distally at the olecranon process.
• Biceps brachii, the prime mover for elbow flexion, can be palpated on the anterior aspect of the arm. Its muscle belly and medial and lateral edges become prominent with elbow flexion.
• The brachioradialis muscle is located laterally in the forearm and participates in elbow flexion and forearm pronation and supination.
• The flexor muscle group of the forearm comprises several muscles involved in wrist flexion and finger flexion.
• The common flexor tendon is a thick tendon that serves as the insertion point for several flexor muscles of the forearm. It's located on the anterior aspect of the medial epicondyle.

Key Structures of the Cubital Fossa

• The cubital fossa is the triangular area on the anterior aspect of the elbow.
• The biceps brachii tendon divides this space. It dives deep into the forearm between the brachioradialis and flexor muscles.
• The lacertus fibrosis, a fibrous branch of the biceps tendon, inserts into the fascia of the forearm medially. It can compress the median nerve at the elbow.

Blood Vessels and Nerves of the Elbow and Cubital Fossa

• The brachial artery is a major artery that runs along the medial aspect of the arm.
• It's palpable medial to the musculotendinous junction of the biceps and has a distinct pulse.
• The median nerve is located medial to the brachial artery.
• It's another round structure, but lacks a pulse.
• The ulnar nerve runs along the medial aspect of the arm, situated halfway between the biceps musculotendinous junction and the medial epicondyle.
• It can be palpated as it dives behind the medial epicondyle and between the medial epicondyle of the humerus and the olecranon of the ulna.

Elbow Joint Movements

• The elbow joint allows for flexion, extension, and pronation and supination.
• Flexion and extension are permitted at the humeroulnar and humeroradial joints, while pronation and supination occur at the proximal radioulnar joint.

Clinical Considerations

• The cubital tunnel located behind the medial epicondyle, can be a site of compression for the ulnar nerve.
• The lacertus fibrosis can contribute to median nerve compression at the elbow.

Important Structures

• Extensor carpi radialis longus (ECRL)
  • It's located laterally in the forearm and participates in wrist extension and radial deviation.
  • Its distal end pops up when activated.
  • Proximally the muscle belly is short and continues as a long tendon to the wrist.
• Extensor carpi radialis brevis (ECRB)
• It's located laterally in the forearm and is also involved in wrist extension and radial deviation.
• It has a long tendon and its muscle belly starts where the ECRL muscle belly ends.
• Its tendon insertion is on the lateral epicondyle.
• The common flexor tendon which is a thick tendon serves as the insertion point for several of the flexor muscles of the forearm and is located on the anterior aspect of the medial epicondyle.
• Its tautness is evident with slight flexion of the wrist and fingers.
• The common extensor tendon which is a thick tendon serves as the insertion point for several of the extensor muscles of the forearm and is located on the posterior aspect of the lateral epicondyle.

Explore the anatomy of the elbow joint with a focus on its bony landmarks. This quiz covers key structures such as the olecranon, medial and lateral epicondyles, and the capitulum. Test your knowledge of palpation points and their significance in functional anatomy.