Frequency and characterization of the accessory heads of the biceps brachii: A multicentric cadaveric study.

ABSTRACT

PURPOSE: The biceps brachii muscle (BBM) is a large and thick muscle on the ventral portion of the upper arm. The scientific literature reports the existence of extra heads. OBJECTIVE: The present work investigated the frequency of occurrence of BBM accessory head(s) in four different Anatomy Laboratories at universities in Northeast Brazil. MATERIAL AND METHODS: Once the upper limbs with an anatomical variation of the BBM heads were identified, the accessory head was evaluated for morphometric characterization (the length, width, and thickness). RESULTS: The sample consisted of 249 upper limbs and the outcomes were 26 members with BBM accessory heads (10.44% of the total sample). Among the 26 members studied was found a single accessory head in 22 (84.62%), two accessory heads in 3 (11.54%), and three accessory heads in 1 (3.85%). BBMs with one, two, and three accessory heads were found, with different origins. The average length, width, and thickness of these accessory heads were 169.39mm, 10.25mm, and 3.39mm, respectively. CONCLUSION: The frequency of BBM accessory heads in a population of northeastern Brazil in this cadaveric study was 10.44%.