Muscle
Dorsal interossei (hand)
ABduct the fingers (DAB)
High-yield
DAB — Dorsal ABduct. Ulnar nerve; first dorsal interosseous wasting is an early sign of ulnar palsy.
Overview
Four bipennate muscles that abduct the fingers from the midline. Deep branch of the ulnar nerve.
Reference facts
- Origin
Adjacent sides of all five metacarpals (bipennate)
- Insertion
Extensor expansions and proximal phalanges of digits 2–4
- Action
Abduct the index, middle, and ring fingers from the middle finger axis; assist the lumbricals
- Innervation
Deep branch of the ulnar nerve (C8, T1)
- Blood supply
Dorsal and palmar metacarpal arteries