See lumbricals (lumbrical muscles) of hand, under muscle, lumbricals (lumbrical muscles) of foot, under muscle.
* * *
1) any of the four small muscles of the palm of the hand that arise from tendons of the flexor digitorum profundus, are inserted at the base of the digit to which the tendon passes, and flex the proximal phalanx and extend the two distal phalanges of each finger
2) any of four small muscles of the foot homologous to the lumbricales of the hand that arise from tendons of the flexor digitorum longus and are inserted into the first phalanges of the four small toes of which they flex the proximal phalanges and extend the two distal phalanges
Medical dictionary. 2011.