The pattern of arrangement of the lumbrical muscles in an African population.

The pattern of arrangement of the lumbrical muscles in the hand of an African population was studied. Sixty-four upper limb specimen from 32 male cadavers between the ages 18 and 40 were obtained from the Department of Anatomy, University of Calabar, Nigeria were used. Ethical approval was granted by the Ethics Committee of the University, and each of the limbs of the cadavers was labeled. Observations were grouped as A, B, C, D, and E and their incidence calculated using simple percentages. Group A constituted 50% and represented the standard pattern. In this group, the first and second bellies of lumbrical muscles arose each from the radial sides of the corresponding flexor digitorum profundus (FDP) tendons, while the third and fourth bellies of the lumbrical muscles arose each from the contiguous sides of the FDP tendons of the middle and ring fingers, and the ring and little fingers, respectively. All the bellies were inserted to their corresponding sides in the radial part of the dorsal digital expansion. Groups B and E constituting 12.5 and 6.25%, respectively, presented single origins and insertions in all the four bellies of the lumbrical muscles. Groups C and D constituting 18.75 and 12.5%, respectively, showed double origins in the third belly of the lumbrical muscle, with the first, second, and fourth having single origins. In conclusion, our study showed variations already reported, and peculiar pattern of lumbrical muscle arrangement in a single hand. Therefore, this study is of anatomical, anthropological, and clinical importance.