A study of variations of the triceps brachii muscle in north Karnataka population

• Author Details:   
• Pratik Khona
• Ashwini C

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Introduction: Triceps brachii muscle is the only muscle of posterior compartment of arm, consisting of three heads–long, lateral and medial. Radial nerve and profunda brachii artery run in the radial groove that separate lateral and medial head. Triceps brachii is a site for intramuscular injections. Evolutionarily triceps has many sub heads which have either fused or disappeared. Therefore, the knowledge of muscle is essential anthropologically and clinically and this study aims to study the anatomical variations of triceps brachii muscle.
Materials & Methods: In the present study, 60 upper limbs from the Department of Anatomy, Belagavi Institute of Medical Sciences, Belagavi and Gadag Institute of Medical Sciences, Gadag were examined for the variations of triceps brachii muscle during routine dissections of undergraduate students. The variations found where neatly dissected and photographs taken wherever necessary.
Result: Out of 60 upper limbs dissected 2 specimens presented with variations of triceps muscle.
Discussion: Both variations seen were fourth head of origin of muscle seen in two different male cadavers in respectively right and left arm. The variations present were seen only unilaterally in both cadavers. The details of these variations will be discussed in the article.
Conclusion: The variations of triceps brachii muscles are mentioned in literature, but are uncommon and if tendinous fourth head are present over the neurovascular bundles they may lead to compression syndrome. Hence the radiologists, surgeons and orthopedicians have to watch out for these while dealing with posterior compartment of arm.

Keywords: Triceps Brachii, Radial Nerve, Profunda brachii artery, Compression syndrome, Fourth head of triceps.