What Is Subclavius Muscle?/Subclavius Muscle is a small triangular muscle, placed between the clavicle and the first rib. Along with the pectoralis major and pectoralis minor muscles, the subclavius muscle makes up the Anterior Axioappendicular Muscles also known as an anterior wall of the axilla.
At a Glance of Subclavius
- Function – Depression and stabilization of the clavicle
- Origin – First rib medially
- Insertion – Middle of the clavicle, inferiorly
- Innervation – Nerve to subclavius (C5, C6)
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Deep muscles of the chest and front of the arm, with the boundaries of the axilla. (Subclavius visible at upper left, above the first rib.) | |
| Details | |
|---|---|
| Origin | first rib and cartilage |
| Insertion | subclavian groove of the clavicle (inferior surface of middle one-third of the clavicle) |
| Artery | thoracoacromial trunk, clavicular branch |
| Nerve | subclavian nerve |
| Actions | depression of clavicle elevation of the first rib |
| Identifiers | |
| Latin | musculus subclavius |
| TA | A04.4.01.007 |
| FMA | 13410 |
| Anatomical terms of muscle | |
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Anatomy of Subclavius Muscle
It arises by a short, thick tendon from the first rib and its cartilage at their junction, in front of the costoclavicular ligament. The fleshy fibers proceed obliquely superolateral, to be inserted into the groove on the undersurface of the clavicle.
Nerve Supply of Subclavius Muscle
- The nerve to subclavius (or subclavian nerve) innervates the muscle. This arises from the junction of the fifth and sixth cervical nerves, from the Superior/upper trunk of the brachial plexus.
- Insertion into the coracoid process instead of the clavicle or into both clavicle and coracoid process. Sternoscapular fasciculus to the upper border of the scapula. Sternoclavicular from manubrium to clavicle between the pectoralis major and coracoclavicular fascia.[rx]
Functions of Subclavius Muscle
- The subclavius depresses the shoulder, carrying it downward and forward. It draws the clavicle inferiorly as well as anteriorly.
- The subclavius protects the underlying brachial plexus and subclavian vessels from a broken clavicle – the most frequently broken long bone.
- The main task of the subclavius muscle is the active stabilization of the clavicle in the sternoclavicular joint during movements of the shoulder and arm. Furthermore, its contraction leads to a depression of the clavicle and elevation of the first rib respectively. These movements, however, play a rather subordinate role.
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