• Latissimus dorsi
  • Teres major
  • Deltoid
  • Triceps brachii
MuscleActionOriginInsertionInnervationBlood supply
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
Teres Major- Adduction of humerus
- Medial rotation of humerus
- Posterior of inferior angle of scapula- Medial portion of intertubercular groove of humerus- Lower subscapular nerve: C5,6,7- Sub scapular artery
- Cicumflex scapular artery
Deltoid- Anterior fibres: Flexion of arm
- Middle fibres: abduction of arm
- Posterior fibres: Extension of arm
- clavicle
- Acromion process
- Spine of scapula
- Deltoid tuberosity- Axillary nerve: C5,6- Deltoid branch of thoracoacromial artery
Triceps Brachii- Extension of Elbow
- Extension of shoulder
- Long head: Infraglenoid tubercle of scapula
- Medial head: Distal half of posterior humerus
- Lateral head: Proximal half of posterior humerus
- Olecranon process of Ulna- Radial nerve; C7, 8- Brachial artery