i screwed up my rotator cuffs 5 years ago. here are the exercises my doctor told me to do, the problems cleared up just fine. make sure you start WITH A LOW WEIGHT!!!!!!!!!!!!!!!!!!!! Dont be a hero, just start with 5 pound dumbless or less, and move up GRADUALLY.
1) stand up, hold dumbells, do lateral raises arms not going above shoulder level
2) stand up, hold dumbells, do frontal raises arms not going above shoulder level
3) stand up, hold dumbells in hands upside down (with thumb towards ground, palms facing outward), and do frontal raises with arms going out 30 degrees from straight ahead, again, arms do not go above shoulder level
4) lie down on side, bend elbow 90 degrees, rotate arm down and up to extent of your range of motion (do both arms)