Infraspinatus

The Infraspinatus muscle is one of the four rotator cuff muscles crossing the shoulder joint and is commonly injured. It is the main external rotator of the shoulder joint.

Origin

• Posterior surface of the scapula (below the spine of the scapula)

Insertion

• Greater tuberosity on the humerus

Actions

• Shoulder abduction
  
  
• External rotation

Innervation

• Suprascapular nerve

Daily uses

• Brushing hair

Example strengthening exercises

• Lateral raise
  
  
• Shoulder external rotation

Example stretches

• Internal rotation stretch
  
  
• Posterior shoulder stretch
  
  
• Posterior shoulder stretch II

Related injuries

• Rotator cuff injury
  
  
• Impingement syndrome

Related muscles

• Supraspinatus
  
  
• Subscapularis
  
  
• Teres minor