The supraspinatus muscle is one of the four rotator cuff muscles and the one most susceptible to injury. When someone tells me they are having a shoulder problem I ask, “Does it hurt to put your jacket on?” If the answer is yes, the overwhelming odds are that the injury is to the supraspinatus muscle and/or tendon.
The four muscles of the rotator cuff are the supraspinatus, supscapularis, teres minor and the infraspinatus. The tendons of these muscles act like ligaments in a way that no other muscle in the body does, and as a result makes them more vulnerable to injury.
The supraspinatus muscle follows the top of the shoulder blade attaching to the top of the humerus, the arm bone. The muscle helps to lift the arm up and is essential to all throwing actions, which is why it is the bane of so many athletes. When the supraspinatus muscle engages or shortens, the arm is pulled sideways away from the body. It also helps to stabilize the shoulder joint keeping the humerus pressed firmly into the shoulder blade.
A bursa is a fluid filled sac that provides a smooth platform for a tendon or muscle to glide over or around bones. Bursitis is when one of these fluid sacs becomes inflamed limiting the movement of the muscle or tendon that it is design to work with. In the case of the supraspinatus muscle and tendon—they pass through a very cramped groove at the top of the shoulder blade and any inflammation of the bursa will reduce the volume of an already small space. Supraspinatus muscle injuries often involve both the tendon and the bursa.
One way of looking at an injury is that every time you feel or tweak it you are re-injuring it. I’ve written before how muscle injuries can be worked through but the same rules don’t apply to ligaments and tendons. What makes something like a rotator cuff injury intense is that you can stop practicing yoga, or whatever athletic endeavor you undertake, in the hopes of healing but the simple of act of getting dressed can keep injuring you over and over again.
Add the difficulty of sleeping positions to the mix and rotator cuff injuries involving the supraspinatus muscle can be very difficult and frustrating to heal. Some things simply require rest in order or heal. Rotator cuff injuries often fall into that category.