• Trapezius
  • Latissimus dorsi
  • Pectoralis minor
MuscleActionOriginInsertionInnervationBlood supply
Trapezius- Upper fibres: Elevation of scapula and rotation of scapula during humerus abduction
- Middle fibres: Retract the scapula
- Lower fibres: Depress the scapula
- Together: Extend neck
- Occiput,
- Medial margin of ligamentum nuchae
- Spinous processes of C7- T12
- Lateral third clavicle,
- Acromion process
- Spine of scapula
- Accessory nerve
- Cervical nerves: C3,4
- Transverse Cervical artery
Latissimus dorsi- Extends humerus
- Depress scapula
- Adducts humerus
- Medially rotates humerus
- Spinous processes of T7-L5
- Sacrum
- Iliac crest
- Ribs 10-12
- Biccipital groove of humerus-Thoracodorsal nerve: C6-8- Thoracodorsal branch of subscapular artery
Pectoralis minor- Depresses shoulder
- Protracts scapula
- Anteromedial surfaces of ribs 3-5
- Coracoid process of scapula- Medial pectoral nerves- Clavicular branch of thoracoacromial trunk