In human anatomy, the infraspinatus muscle is a thick triangular muscle, that is one of the four muscles of the rotator cuff. This is an essential move for anyone recovering from a shoulder injury. 1. Lay comfortably on your side with your head supported. 2. Keep elbow in line with body as you slowly raise your hand. 3. Lift hand until it points to the ceiling 4. Slowly lower back to your side. 5. Don't allow shoulder to roll forward of backwards.