The Most Under Trained Muscle of The Shoulder and How to Strengthen It
The Rear Deltoid
The Deltoid muscle is a large muscle that surrounds the shoulder shoulder joint and is involved in most motions of the shoulder. It has an anterior (front), middle, and posterior (rear). While common to see training programs that focus on the anterior and middle portions of the muscle, the rear deltoid is most commonly left out.
The rear deltoid is the most under trained muscle of the shoulder. A weak rear deltoid leads to an imbalance in shoulder motion and contributes to chronic shoulder pain.
How To Strengthen? The Clock
Clock's are an easy exercise you can do to strengthen the rear deltoid as well as inferior trapizius muscle fibers which are also commonly week and contribute to shoulder pain.
To perform: Standing or seated, keeping arms straight, raise to '10 o clock and 2 o clock position' and press back, holding for 2 seconds. Next move arms to '9 and 3' and press back, holding for two seconds. Move to '5 and 7' and repeat. Continue cycle for one minute.
Exercise is easily progress by laying on stomach (so fighting gravity) or with use of a band wrapped around pole.