Injuries to the rotator cuff are common. They can occur during sporting activities or just doing daily activities. Pain and/or injury to the rotator cuff usually occur with repetitive motions such as throwing a ball, gardening and other motions where you might overuse your shoulders. The first step is to have your pain diagnosed to make sure there is not a tear. If the rotator cuff is torn you can make it worse with the wrong exercise. If it is not torn there are exercises you can do to help.
Internal and External Rotation
Lie on your left side. Make sure you do not roll forward or backward while doing this exercise. Keep your shoulders and hips stacked over one another. Hold onto a weight, soup can or plastic container filled with water or sand with your right hand. Rest your right elbow on your waist. Throughout this exercise your right elbow needs to stay in contact with your body--do not let it lift up. Pivoting from your elbow, lower your right hand down and bring your forearm across your belly. Then pivot on the elbow and lift the right hand and forearm up to a 90-degree angle. Your right elbow should still be resting on your waist and your palm is facing forward. Do 8 to 12 repetitions.
Side Shoulder Raise
Sit up straight in a chair. Hold a weight or soup can in your hands. Lift your arms up to the side with your palms facing down. Try to draw your arms back so they are straight out to the side. If this causes pain, bring the arms slightly forward. Try to keep the elbows straight but not locked. Do 8 to 12 repetitions.
Sit at the front edge of a chair. Keeping the back straight, lean froward and rest your left arm on your knees for support. Let the right hand dangle to the outside of your right leg and hold a weight for more resistance. Make 8 to 12 clockwise circles and then go counterclockwise. Try to allow the shoulder to relax. The picture here shows standing, which can strain the back.
Standing Broom Swing
Stand up straight and hold a broom in your hands so that your palms face your body and place your hands a bit wider than hip-width apart. Swing the broom up as high as you can to the right without twisting the body. Then swing it to the left. Go slowly and with control. Do 8 to 12 repetitions on each side. See the link in References for Rotator Cuff Strain Rehabilitation Exercises.
Stand in a doorway with your right foot forward and left foot back. Tuck both elbows into your waist. Rotate the hands out and place your palms against the doorway so they are waist height. Bend your right knee and keeping the shoulders over the hips, lunge forward until you feel a gentle stretch. Keep the elbows tucked into your waist. Hold for a slow 30-second count. Release and switch legs.