There's another test you can do to assess the status of the supraspinatus, one of the four small rotator cuff muscles which runs along the top of the shoulder blade and inserts via the tendon at the top of the arm or humerus bone, and is involved in shoulder abduction. (fitnessandpower.com)
Using your feet to drive the movement, inhale as you roll up, stopping at the top of the shoulder blades. (mindbodygreen.com)
The biceps brachii consists of short and long head, which are two smaller muscles, both running down the upper arm from the top of the shoulder blade and attaching to the radius bone. (fitnessandpower.com)