Gross anatomical observations of the palmar interossei muscles in humans: A cadaveric study

Abstract

Objectives: The interossei muscles of the hand provide a foundation for all the intrinsic hand movements. They occupy the intervals between the metacarpal bones and are divided into a palmar and dorsal set. The palmar interossei are smaller than dorsal interossei and lie on the palmar surface of the metacarpal bones rather than between them. The present study aimed to evaluate the number and variations in the palmar interosseous muscles. Methods: Thirty hands from 15 human cadavers (10 males and 5 females, of age ranging from 50 to 65 years) in the Department of Anatomy, Kasturba Medical College, Manipal were studied to explore the prevalence of palmar interosseous. Results: The palmar interossei showed variations, i.e., bipennate, hypertrophied muscle and absence of first palmar interossei. These findings are rare and are less reported. The study also agrees upon the prevalence of four palmar interossei as suggested by different studies. The nerve supply to the interossei when traced was normal in all the specimens and was provided by the deep branch of the ulnar nerve. Conclusion: Ample knowledge of the possible variations in these muscles is very essential for clinicians and surgeons dealing with fractures, stiff joints, claw toe or tendon transfers.