I have been having problems with my right shoulder/deltoid tendon . It is usually sore, & a little hot, & once or twice a day, usually at night when I am lying down , I will get a severe cramp ( maybe a nerve cramp), that lasts about 30 seconds. The movement & strength in the shoulder is good. my Orthodepdic doc, gave me a cortisone shot in the shoulder about 1 month ago & I am going for Physical Therapy; the Physical Therapist indicated that I have quite a few muscle knots in the muscle & in the neck/back of the shoulder. I have had an EMG & MRI of the Shoulder, & except for some calcification & arthritis, these tests did not show anything that would cause the severe, sudden pain that comes on. They are guessing that perhaps a muscle is having a spasm & causing nerve pain. Any thoughts or recommendations would be welcome