The Hypothenar Muscles
The heel of the hand is called the hypothenar ("HIGH-poh-theen-nar") eminence. The surface muscles of the hypothenar eminence are abductor digiti minimi and flexor digiti minimi. They originate on the pisiform bone, the hook of the hamate bone, and the flexor retinaculum. They insert on the base of the proximal phalanx of the little finger. Their action is to abduct and flex the little finger.
The hypothenar group forms the little-finger side wall of the hand, and can be seen on both dorsal and palmar views.