Topographic and Biometric Study of Radial Nerve Branches to the Muscles of the Anterior Compartment of the Arm/ Estudio Topografico y Biometrico de los Ramos del Nervio Radial para los Musculos del Compartimiento Anterior del Brazo

The radial nerve is a terminal branch of the brachial plexus that innervates the entire posterior compartment of the upper limb. Researches have shown that the branches can contribute to innervation of the muscles from the anterior compartment of the arm. This study sought to identify branches of radial nerve for brachialis and coracobrachialis muscles and its clinical value during surgery. Dissection was performed in 60 arms, from 30 corpses selected from the Human Anatomy Laboratories of Universidade Estadual de Ciencias da Saude de Alagoas (UNCISAL). In each arm, three segments of the same proportion were considered (proximal, middle and distal) in order to observe the number of radial nerve branches to brachialis and coracobrachialis muscles. Branches were identified in 4 of the 60 upper limb (6.66%) with the following distribution: nerve with 1 branch to the brachialis muscle in the distal third (1.66%); with 1 branch to the middle third of the coracobrachialis (1.66%) and 5 branches to the coracobrachialis muscle in the proximal third; 1 branch being found in an upper limb (1.66%) and 4 branches in the other upper limb (1.66%). The event was not bilaterally in the same body, and in four cases there was no branching, but only communication with other terminal nerves of the brachial plexus. In conclusion, although most authors do not describe the possibility of the occurrence of radial nerve branches to the muscles of the anterior compartment of the arm, this condition exists as an anatomical variation. KEY WORDS: Anatomy; Radial nerve; Brachialis muscle; Coracobrachialis muscle. El nervio radial es un ramo terminal del plexo braquial que inerva el compartimiento posterior del miembro superior. Diversos estudios han mostrado que sus ramos pueden contribuir a la inervacion de los musculos del compartimiento anterior del brazo. El presente estudio tuvo como objetivo identificar ramos del nervio radial dirigidos a los musculos braquial y coracobraquial y su importancia clinica durante las cirugias. Para ello, se disecaron 60 brazos de 30 cuerpos formolizados en los Laboratorios de Anatomia Humana de la Universidad Estadual de Ciencias de la Salud de Alagoas, Brasil (UNCISAL). En cada brazo, se consideraron tres partes de similares proporciones (proximal, medio y distal) para localizar los ramos dirigidos a los musculos mencionados. En 4 de los 60 brazos (6,66%) se identificaron ramos con la siguiente distribucion: un ramo para el musculo braquial en el te