16. Elbow joint connections if the bones of the forearm

Covers the elbow as a hinge joint formed by the humerus, ulna and radius, with its capsule, collateral and annular ligaments, relations, muscle movements, blood and nerve supply, and Hilton's rule. It then describes the superior and inferior radioulnar joints and the interosseous membrane that bind the two forearm bones together.

Inside: 10 sections · 3 labelled pictures · 12 flashcards · 2 min

Topic 16 of 236 in the MU Pleven syllabus for Anatomy Bones and Muscles (Medicine, Year 2). The free AceMed note covers it in 10 sections, about 267 words (2 min of reading), with 12 flashcards.

Elbow Joint

Type

Hinge synovial joint (ginglymus type).
Allows flexion and extension.

Articulating Bones

Humerus: trochlea + capitulum.
Ulna: trochlear notch (greater sigmoid cavity).
Radius: head of radius (superior concave surface).

→ Together they form humeroulnar and humeroradial joints (function as one joint).

Joint Capsule

Thin and loose anteriorly & posteriorly.
Strong and reinforced by collateral ligaments on sides.

Ligaments

1. Ulnar collateral ligament (medial)

From medial epicondyle → medial margin of trochlear notch.
Triangular; resists valgus stress.

2. Radial collateral ligament (lateral)

From lateral epicondyle → blends with annular ligament.
Resists varus stress.

3. Annular ligament

Surrounds head of radius.
Holds it against ulna (radial notch).
Important for pronation–supination.

Relations

Anterior: brachialis, biceps tendon, median nerve, brachial artery.
Posterior: triceps tendon, anconeus, olecranon bursa.
Medial: ulnar nerve (behind medial epicondyle).
Lateral: common extensor muscles, supinator.

Movements

Flexion: biceps brachii, brachialis, brachioradialis.
Extension: triceps, anconeus.
Supination–pronation occur at proximal radioulnar joint (functionally related).

Blood Supply

Anastomosis around elbow (branches of brachial, radial, ulnar, profunda brachii).