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
Frequently asked questions
What does the dorsal interossei (hand) do?
The dorsal interossei (hand) abduct the index, middle, and ring fingers from the middle finger axis; assist the lumbricals.
What nerve innervates the dorsal interossei (hand)?
The dorsal interossei (hand) is innervated by the deep branch of the ulnar nerve (C8, T1).
Where does the dorsal interossei (hand) attach?
The dorsal interossei (hand) originates from the adjacent sides of all five metacarpals (bipennate) and inserts on the extensor expansions and proximal phalanges of digits 2-4.
What is the blood supply of the dorsal interossei (hand)?
The dorsal interossei (hand) is supplied by the dorsal and palmar metacarpal arteries.