PALMAR INTEROSSEI
Origin
Ant shafts of 1, 2, 4, 5 MCs (unipennate)
Action
Adduct to axis of middle finger. Flex MCP jnt whilst extending IP jnts
Insertion
Prox phalanges and dorsal extensor expansion on ulnar side of index and radial side of ring and little fingers and to ulnar sesamoid of thumb
Nerve
Deep br of ulnar N (T1)
