The morphometric parameters of the biceps brachii: cadaveric study

Abstract

Background: The biceps brachii (BB) is a fusiform muscle comprising of two muscular bellies located in the anterior compartment of the arm. Its primary function includes elbow flexion and forearm supination.

Purpose: The study aimed to examine the morphometric parameters of the BB in adult cadaveric specimens.

Methods: This dissection-based study examined the anatomy of the BB in 40 arms taken from 20 Thiel embalmed European cadavers, including 13 males with an average age of 81 years and seven females with an average age of 84 years. The investigation included an observational inspection of the BB morphology and collected 19 parameters, comprising the lengths and widths of the short and long head tendons and muscle bellies.

Results: The observation analysis showed that the anatomy of the BB consisted mainly of two muscle bellies: a short head and a long head. An additional third humeral head, originating from the anteromedial aspect of the mid of the humerus and inserted into the common biceps tendon, was observed in four (10%) specimens. The average lengths of the short head and long head were 35.98 ± 3.44 cm and 38.90 ± 3.40 cm, respectively. There was no difference in the BB parameters according to the arm sides. However, the male specimens showed greater BB parameters than the female specimens.

Conclusion: The short head had a greater muscle belly, while the long head had a longer origin and insertion tendons. The BB parameters were correlated positively with the humerus length.

Keywords: Biceps brachii; Biceps brachii morphology; Biceps brachii parameters; Long head of biceps brachii; Short head of biceps brachii; Supernumerary head of biceps muscle.