Opponens digiti minimi
The opponens digiti minimi is a triangular muscle in the hand. It plays an integral role in the movement and control of the fifth metacarpal, or the little finger. It draws the metacarpal bone of the little finger to the front and rotates it in a lateral direction. This action deepens the hollow of the palm and brings the little finger into opposition with the thumb. It is located below the flexor digiti minimi brevis. The opponens digiti minimi is the largest of the hypothenar eminence. This term refers to a group of three hypothenar muscles located on the outside of the palm of the hand. These muscles control the little finger. The other two muscles in this group are the abductor digiti minimi and flexor digiti minimi. The origin of the opponens digiti minimi muscle is in the lateral border of the flexor retinaculum of the wrist. It also originates from the hamulus of the hamate bone. Its insertion is in the whole length of the metacarpal bone of the little finger, along its ulnar margin.