There are approximately 20 muscles in the human hand, though another 15 or so muscles in the forearm are needed to make the hand move properly. The muscles that attach in the forearm are called extrinsic muscles, while those that attach in the hand are intrinsic muscles. Along with bones, tendons and ligaments, these muscles allow the human hand to do the intricate and precise movements it is capable of.
Among the muscles found in the hand are the opponens digiti minimi muscle, which runs along the outside of the hand, and the dorsal interosseous muscles, which are found at the top of the hand and help control the fingers. The flexor pollicis, abductor pollicis and opponens pollicis muscles are in the palm of the hand and control the thumb. The lumbrical muscles, which control the fingers, are also located in the palm.
Additional hand muscles include the dorsal interosseous muscle, which is located near the web between the thumb and the forefinger, as well as the abductor digiti minimi, the flexor digiti minimi and the opponens digiti minimi muscles that also control the fingers. The flexor digitorum profundus muscles are found near the tips of the fingers, while the the pronator quadratus muscle is found in the wrist.