Upper limb
Pectoralis Minor
Musculus pectoralis minor
- Origin
- Outer surface of ribs 3-5 (sometimes 2-4), near the costochondral junction
- Insertion
- Coracoid process of the scapula
- Function
- Pulls the scapula forward and downward (protraction/depression); accessory muscle of respiration with a fixed shoulder girdle
- Innervation
- Medial pectoral nerve (C8-T1)
- Movement & chain
- Tilts the scapula anteriorly and, when shortened, can disrupt scapulothoracic rhythm, leading to a reduced subacromial space during arm elevation
- Palpation
- Palpable deep to pectoralis major by pressing curved fingers under the lateral border of the muscle, just medial to the coracoid process
- Clinical
- Shortening/hypertonicity of this muscle is a common cause of thoracic outlet syndrome due to compression of the brachial plexus and subclavian artery beneath the tendon
- Segmental innervation
- Myotome C8-T1.
- In clinical practice
- An important focus point in postural correction and stretching exercises for the prevention and treatment of thoracic outlet syndrome and an anterior shoulder posture.
- Region in the model
- Upper limb