Elbow

Humerus

The upper-arm bone.

Ulna

The medial forearm bone on the pinky side.

Radius

The lateral forearm bone on the thumb side.

Humeroulnar Joint

The joint between the trochlea of the humerus and the trochlear notch of the ulna; mainly allows flexion/extension.

Humeroradial Joint

The joint between the capitulum of the humerus and the radial head; aids in flexion/extension and stabilizes rotation.

Proximal Radioulnar Joint

The joint between the radial head and the radial notch of the ulna; mainly allows supination/pronation.

UCL (Ulnar Collateral Ligament)

Ligament that stabilizes against valgus forces, commonly injured in overhead athletes.

RCL (Radial Collateral Ligament)

Ligament that stabilizes against varus forces.

Annular Ligament

Ligament that wraps around the radial head and allows smooth rotation of the forearm.

Flexion of the elbow

Movement resulting in a decrease in the angle between the forearm and the upper arm, primarily performed by the biceps brachii, brachialis, and brachioradialis.

Extension of the elbow

Movement that increases the angle between the forearm and the upper arm, primarily performed by the triceps and anconeus.

Supination

Rotational movement of the forearm that turns the palm upward, primarily performed by biceps brachii and supinator.

Pronation

Rotational movement of the forearm that turns the palm downward, primarily performed by pronator teres and pronator quadratus.

UCL Sprain/Tear

Injury caused by repetitive valgus stress, leading to medial elbow pain and instability.

Lateral Epicondylitis (Tennis Elbow)

Injury caused by overuse of wrist extensors leading to pain on the lateral elbow.

Medial Epicondylitis (Golfer’s Elbow)

Injury caused by overuse of wrist flexors, resulting in medial elbow pain.

Radial Head Subluxation (Nursemaid’s elbow)

Injury caused by sudden traction on a child’s arm, leading to radial head movement under the annular ligament.

Biceps Tendon Rupture

Injury caused by forceful load during flexion or supination, often characterized by a 'pop' sound.

Olecranon Bursitis

Condition caused by prolonged leaning on the elbow or trauma, resulting in swelling over the posterior elbow.