Muscles of the hand: Overview (English)

Aside from the classification into 3 groups, the muscles of the hand can also be divided into 5 groups, namely the thenar, adductor, hypothenar, central and interosseous muscle compartments. The thenar compartment contains the short muscles of the thumb and includes the abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis muscles. The adductor compartment contains the adductor pollicis muscle. The hypothenar compartment includes the abductor digiti minimi, flexor digiti minimi and opponens digiti minimi muscles. The palmaris brevis is sometimes considered part of the hypothenar compartment, however, functionally, it is not related to movement of the little finger. The central compartment contains the lumbrical muscles (4), which are found between the metacarpals and attach proximally to the tendons of flexor digitorum profundus muscle. The interosseous compartments contain either the dorsal interossei (4), which are small muscles found between the metacarpal bones on the dorsal surface of the hand, or the palmar interossei (3), which represent their palmar counterparts.