The "I" Flex
Grab a light hand weight or water bottle or can of soup. Lay face down on exercise bench, exercise ball, or bed with your arms hanging down, palms out. Keeping your elbows straight, slowly raise weight forward until arms are level with your body, thumbs toward ceiling. Prtend your body is a clock; head 12, feet 6... your arms should go no higher than 1 and 11. If you feel pain, don't lift as high, staying within a comfortable range of motion. Your shoulder will improve and you can expand your range of motion over time
10-12 repetitions at a light weight

The "T" Flex
In same start position and with same weight, turn palm forward and raise to 3 on right and 9 on left, thumb toward ceiling. slowly lower back to 6 straight with the feet.
again 10-12 repititions with a light weight

The "Y" Flex
Next, raise arms to your side, slightly in front of you. Do one arm at a time, bringing right arm to 2 and left to 10. This is more advanced that is why we only do one arm at a time. be careful and again if there is pain only go as high as you can without pain. Slowly you can regain your range of motion in many cases.
again 10-12 repetitions with a light weight

This can help with pinched nerves, arthritis, frozen shoulders and muscle tightness! Good Luck!