Actions & innervation of Coracobrachialis.
Knowledge of origins & insertions is NOT required but an appreciation of the surface topography is required.
Curriculum
| Origin | Coracoid process of scapula |
| Insertion | Antero-medially on Shaft of Humerus |
| Nerve supply | Musculocutaneous nerve |
| Actions | Flexion of the arm and weak adductor |
Though the curriculum says origin and insertion not required, we’ve included them as that knowledge will help you understand the movements better based on muscle orientation.
Coracobrachialis muscle Origin and Insertions – Image modified from BodyParts3D, © The Database Center for Life Science licensed under CC Attribution-Share Alike 2.1 Japan
The muscle is named as per it’s origin and insertion. From coracoid to the arm (Brachium = Arm) hence Coraco-brachialis.
The position of muscle should help you understand the actions when it contracts. It’ll pull the arm anteriorly (flexion) and medially (adduction)
All the anterior arm muscles – Coracobrachialis, Brachialis and Biceps brachii are supplied by the same nerve – The Musculocutaneous nerve, the terminal branch of the lateral cord of the brachial plexus (C5-C7). The nerve becomes lateral cutaneous nerve of forearm to supply lateral part of forearm. Muscles of Upper Arm and Skin of Forearm are supplied.
Relevant pearl