Subscapularis

Subscapularis is one of the four rotator cuff muscles which cross the shoulder joint. The muscle also acts to hold the head of the humerus in position and prevents it moving forwards. It is shown here with a couple of ribs cut away at the front.

Origin

• Anterior (costal) surface of the scapula

Insertion

• Lesser tuberosity of the humerus

Actions

• Internal rotation
  
  
• Adduction

Innervation

• Upper and lower subscapular nerves

Daily uses

• Tucking the back of your shirt into your trousers

Example strengthening exercises

• Diagonal extension

Example stretches

• External rotation stretch

Related injuries

• Inflammation of the subscapularis muscle
  
  
• Rotator cuff injuries

Related muscles

• Supraspinatus
  
  
• Infraspinatus
  
  
• Teres minor