Pectoralis Major
Pectoralis major is the largest and most superficial of the two chest muscles. Pec major and the anterior fibres of Deltoid work closely together. Pec-fly and push-up exercises work the Pectoralis major.
Origin
- Medial 1/2 of the clavicle.
- Costal cartilages of the first 6 ribs.
- Sternum.
Insertion
- Intertubercular groove (between the greater and lesser tubercles) of the humerus.
Actions
- Shoulder flexion.
- Internal rotation.
- Adduction.
Innervation
- Lateral and medial pectoral nerves.
Daily uses
- Using roll-on deodorant.
Example strengthening exercises
- Pec fly using a resistance band.
- Chest Press using a resistance band.
Example stretches
- Chest stretch.
- Chest stretch with a partner.
Related injuries
- Pectoral strain.
Related muscles
- Pectoralis minor.
