Flexor Pollicis Brevis Muscle. Anatomical Study and Clinical Implications

INTRODUCTION: This paper reports anatomical study of nature, incidence, innervation and clinical implications of Flexor Pollicis Brevis muscle (FPB). MATERIAL AND METHODS: The anatomical dissection of 60 limbs from 30 cadavers were performed in the Department of Anatomy of Medical School of Catholic University of São Paulo. RESULTS: The superficial head of FPB has been innervated by the median nerve in 70% and in 30% it had double innervation. The deep head of FPB were absent in 14%, in 65%, occurred a double innervation. In 17.5% by deep branch of ulnar nerve and in 3.6% by recurrent branch of median nerve. CONCLUSION: The pattern of innervation more frequent in relationship to the flexor pollicis brevis muscle and should be considered as a normal pattern is that superficial head receives innervation of branches of median nerve and the deep head receives innervation of ulnar and median nerve.