Unilateral Absence of Second, Third and Fourth Lumbricals: A Rare Case Report with an Evolutionary Significance.

Lumbricals are the intrinsic muscles of the hand resembling the earthworms. During routine dissection of the hand of a 58 years old male cadaver,we found a rare variation of absence of the second,third and fourth lumbricals of the left hand while the right hand showed no abnormality. Lumbricals act as flexor of the metacarpophalangeal joint and extensor of the interphalangeal joint but owing to their movable attachments, their function is difficult to visualize. Variability of the muscle both in morphology and function indicates the ongoing process of evolution.