I'm a right-handed tennis player with some LEFT shoulder and Left upper back tenderness. This first arose after a couple weeks where I practiced a lot more than usual. I feel some tightness in the upper thoracic/lower cervical and tenderness in the upper pectoral area and tenderness under the left clavicle. (My right side feels great!?) Could this be a result of imbalance with strengthened right sided muscles pulling the spine and shoulder girdle out of alignment? If so will standard upper back/shoulder therapy exercises for the left side be beneficial? I know the standard rotator cuff therapy and have the Therabands, etc.