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 horizontal abduction.
External rotation. Shoulder extension - Innervation – Suprascapular nerve.
- Daily uses – Brushing hair.
- Example strengthening exercises – Lateral raise.
Shoulder external (lateral) rotation. - Example stretches – Internal rotation stretch.
Posterior shoulder stretch.