Elbow joint and junctions of forearm

What type of joint is the elbow joint?

Synovial hinge joint.

What are the main movements of the elbow joint?

Flexion and extension.

What bones form the elbow joint?

Humerus, ulna, and radius.

What 3 articulations are included in the elbow joint region?

Humeroulnar, humeroradial, and proximal radioulnar joints.

What forms the humeroulnar articulation?

Trochlea of humerus with trochlear notch of ulna.

What is the main function of the humeroulnar articulation?

Main hinge movement: flexion and extension.

What forms the humeroradial articulation?

Capitulum of humerus with head of radius.

What movements does the humeroradial articulation help with?

Flexion, extension, pronation, and supination.

What forms the proximal radioulnar joint?

Head of radius with radial notch of ulna.

What type of joint is the proximal radioulnar joint?

Synovial pivot joint.

What movement occurs at the proximal radioulnar joint?

Pronation and supination.

What strengthens the elbow capsule medially and laterally?

Collateral ligaments.

What are the 3 parts of the ulnar collateral ligament?

Anterior band, posterior band, and transverse band.

Which part of the ulnar collateral ligament is strongest?

Anterior band.

What ligament is commonly injured in throwing athletes?

Ulnar/medial collateral ligament.

Where does the radial collateral ligament attach/blend?

It extends from the lateral epicondyle and blends with the annular ligament.

What does the annular ligament do?

Encircles the head of radius and holds it against the radial notch of ulna.

What are the main elbow flexors?

Brachialis, biceps brachii, and brachioradialis.

: What are the main elbow extensors?

Triceps brachii and anconeus.

What are the main pronators of the forearm?

Pronator teres and pronator quadratus.

What are the main supinators of the forearm?

Biceps brachii and supinator.

During pronation, what happens to the radius?

The radius crosses over the ulna.

What is the carrying angle?

The normal lateral deviation of the forearm from the arm when the elbow is extended.

Why is the carrying angle useful?

It allows the forearm to clear the hips during walking.

In whom is the carrying angle usually larger?

Females.

What is cubitus valgus?

Increased carrying angle.

What is cubitus varus?

Decreased carrying angle, also called gunstock deformity.

What supplies blood to the elbow joint?

Arterial anastomosis around the elbow.

Which arteries contribute to the elbow anastomosis?

Brachial artery branches, radial recurrent, ulnar recurrent, collateral arteries, and interosseous recurrent artery.

What nerves supply the elbow joint?

Musculocutaneous, radial, median, and ulnar nerves.

What structures are at risk in elbow dislocation?

Brachial artery and median nerve.

What is medial epicondylitis also called?

Golfer's elbow.

Medial epicondylitis involves overuse of which muscles?

Forearm flexors and pronators.

What is lateral epicondylitis also called?

Tennis elbow.

Which muscle is especially involved in lateral epicondylitis?

Extensor carpi radialis brevis.

What are the 3 main junctions between radius and ulna?

Proximal radioulnar joint, interosseous membrane, and distal radioulnar joint

What do the radioulnar joints allow?

Pronation and supination.

what ligament stabilizes the proximal radioulnar joint?

Annular ligament.

What type of joint is the middle radioulnar joint?

Fibrous joint/syndesmosis.

What are the 3 main functions of the interosseous membrane?

Holds radius and ulna together, transmits forces, and provides muscle attachment.

What is the direction of most interosseous membrane fibers?

Downward and medially from radius to ulna.

Why is the direction of interosseous membrane fibers important?

It helps transfer forces from radius to ulna.

What attaches to the interosseous membrane?

Deep forearm muscles.

What type of joint is the distal radioulnar joint?

Synovial pivot joint.

What forms the distal radioulnar joint?

Head of ulna and ulnar notch of radius.

What important structure stabilizes the distal radioulnar joint?

Articular disc/triangular fibrocartilage complex, also called TFCC.

What does the TFCC do?

Stabilizes the distal radioulnar joint, separates it from the wrist joint, and helps transmit forces.

At the distal radioulnar joint, which bone moves around which?

Radius moves around the ulna.

Which joint allows flexion and extension of the elbow?

Elbow joint/humeroulnar and humeroradial articulations.

Which joints allow pronation and supination?

Proximal and distal radioulnar joints.

Which structure transfers force from radius to ulna?

Interosseous membrane.

Which structure separates the distal radioulnar joint from the wrist joint?

TFCC/articular disc.

Nursemaid's elbow involves which ligament?

Annular ligament.