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 deoderant

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