I gauage alot of my functional rehab on the range and subsequent use of mid to upper thoracic extension when performing overhead activities. This should not be to the detriment of increased lumbar extension and hence abdominal support is also required. Further prggression address thoracic rotation and its use, pec monor length and its affect on the scapula, and lasty really the balancing of therotator cuff. Without the other factors the cuff will just be overworked and blow up!!