Upper limb

Extensor Digiti Minimi

Musculus extensor digiti minimi

Origin

Lateral epicondyle of the humerus (common extensor tendon)

Insertion

Extensor hood (dorsal aponeurosis) of the little finger, with an extension to the base of the middle phalanx

Function

Extends the little finger at the metacarpophalangeal and interphalangeal joints, independently of the other fingers

Innervation

Radial nerve (deep branch/posterior interosseous nerve), C7–C8

Movement & chain

Allows independent extension of the little finger, such as raising the little finger while the other fingers remain flexed.

Palpation

The tendon can be traced ulnar to the extensor digitorum tendon on the dorsum of the hand during isolated little finger extension.

Clinical

Because extensor digitorum also sends a tendon to the little finger, active little finger extension is often largely preserved despite an isolated loss of function or rupture of this muscle.

Segmental innervation

Part of the C7–C8 myotome via the deep branch of the radial nerve.

In clinical practice

Skin and pressure point inspection; maintain comfortable positioning and proper body mechanics during patient handling and daily care.

Region in the model

Upper limb