Coracobrachialis Muscle Anatomy

Overview
Origin Coracoid process of the scapula
Insertion Midshaft of humerus (distal to the crest of the lesser tubercle)
Action Shoulder adduction
Shoulder flexion
Nerve Musculocutaneous nerve (C5, C6, C7)
Artery Brachial artery

Location & Overview

The coracobrachialis is located in the upper arm. It is one of the three muscles which attaches to the coracoid process of the scapula. The other two are: the short head of the biceps brachii muscle and the pectoralis minor muscle. The coracobrachialis is the smallest of these three muscles [1].

coracobrachialis from an anterior view

The coracobrachialis from an anterior view.

Origin & Insertion

The coracobrachialis originates at the coracoid process of the scapula and inserts at the midshaft of the humerus, which is distal to the crest of the lesser tubercle (the insertion is located between the attachments of the triceps brachii’s medial head and the brachialis muscle) [2].

The origin of the coracobrachialis muscle

The origin of the coracobrachialis muscle is the coracoid process of the scapula and is highlighted here in red.

The insertion of the coracobrachialis muscle

The insertion of the coracobrachialis muscle is midshaft of humerus (distal to the crest of the lesser tubercle) and is highlighted here in blue.

Actions

The main actions of the coracobrachialis muscle are: shoulder adduction (lifting your arm outwards to your side) and shoulder flexion (lifting your arm up and in front of you) [3] [4].

Innervation

The coracobrachialis is innervated by the musculocutaneous nerve (C5, C6, and C7) [5].

Blood Supply

Blood is supplied to the coracobrachialis by the brachial artery [6].

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Coracobrachialis Flashcards

References

References
1, 3 Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.
2 Szewczyk, B., Polguj, M., Paulsen, F. et al. A proposal for a new classification of coracobrachialis muscle morphology. Surg Radiol Anat 43, 679–688 (2021). https://doi.org/10.1007/s00276-021-02700-1
4, 6 Georgiev GP, Landzhov B, Tubbs RS. A Novel Type of Coracobrachialis Muscle Variation and a Proposed New Classification. Cureus. 2017;9(7):e1466. Published 2017 Jul 13. doi:10.7759/cureus.1466
5 Chouke, K. S. (1924). Variation of the coracobrachialis muscle. The Anatomical Record, 27(3), 157-163.