Summary
Origins
- Medial half of 🦴 clavicle
- Sternum
- Costal cartilages of ribs 1-6 (sometimes 1-7)
Insertions
- Crest of the greater tubercle of the humerus (lateral lip of 📍 bicipital groove)
Actions
- Flexes the shoulder (especially the clavicular head)
- Adducts the shoulder
- Medially rotates the shoulder
- Assists in extending the shoulder from a flexed position (sternal head)