Abductor digiti minimi of the hand

Origin	Pisiform and FCU tendon
Insertion	Two slips: 1 - Ulnar side of fifth digit proximal phalanx 2 - Ulnar border of EDQ aponeurosis
Action(s)	Abducts 5th digit and helps flex little finger proximal phalanx at MP joint
Nerve Supply	Deep branch of ulnar nerve, C8
Arterial Supply	Ulnar artery
Physical Exam
Clinical Importance	This muscle may contract in rheumatoid arthritis and keep the finger abducted
Disease States	Rheumatoid arthritis
Discussion	The Abductor minimi digiti (Abductor digiti quinti) is situated on the ulnar border of the palm of the hand. It arises from the pisiform bone and from the tendon of the Flexor carpi ulnaris, and ends in a flat tendon, which divides into two slips; one is inserted into the ulnar side of the base of the first phalanx of the little finger; the other into the ulnar border of the aponeurosis of the Extensor digiti quinti proprius. In case of polydactyly it may insert to the sixth finger instead, if there is one.