Dorsal Interossei (Hand)
Hand
Remember 'DAB' — Dorsal ABduct. They spread your fingers apart. There are 4 of them.
Function
Abduct fingers away from middle finger, flex MCP, extend IP joints
Origin
Adjacent sides of two metacarpals each
Insertion
Extensor expansions and bases of proximal phalanges
Innervation
Deep branch of ulnar nerve (C8-T1)