How to increase shoulder flexibility using a simple exercise that anyone can do at home. Shoulder pain is usually related to a lack of shoulder joint mobility. I don't have to tell you how frustrating it is to have upper back, neck and shoulder pain! Not being able to reach your arms overhead severely limits your lifestyle. But there's good news...simply practicing this easy shoulder mobility exercise a few times a week keeps your shoulder joints mobile and lubricated, relieving your neck ache. This shoulder flexibility exercise will also help you prevent future shoulder injury. This exercise shows you how improve your range of motion and free upper back tension.