Flexor digiti minimi muscle

One of the three hypothenar muscles, the flexor digiti minimi originates from one of the carpals (hamate) and inserts into the proximal phalanx of the pinky.  It flexes the pinky, and is innervated by the ulnar n.

Action: Flexes the fifth digit

Innervation: Ulnar n.

Origin: Hamate (carpal) bone

Insertion: Proximal phalanx of fifth digit