Upper limb

Extensor Hood of the Little Finger

Aponeurosis dorsalis digiti V manus

Origin

Dorsal aspect of the base of the proximal phalanx of the little finger, where the tendons of extensor digitorum and extensor digiti minimi join the lumbrical and the interossei

Insertion

Base of the middle and distal phalanx of the little finger

Function

Distributes the pulling force of the extensors and intrinsic hand muscles across the proximal and distal interphalangeal joints of the little finger

Innervation

Mixed: radial nerve (extensor digitorum/digiti minimi) and ulnar nerve (lumbrical and interossei)

Movement & chain

Allows the metacarpophalangeal joint of the little finger to flex while the interphalangeal joints remain extended, such as during a precision grip with the little finger.

Palpation

Palpable over the 5th MCP joint and dorsum of the little finger; receives both EDC and EDM tendons.

Clinical

Extensor apparatus of the 5th digit; prone to ulnar drift and extensor subluxation in rheumatoid hand deformities.

Segmental innervation

C7–C8 (radial nerve) & C8–T1 (ulnar nerve)

In clinical practice

Focus on hand function and edema prevention; ensure IV cannulas and splints maintain functional hand position to prevent joint contractures.

Region in the model

Upper limb