Many people have shoulder pain or tightness that does not get discovered until you do a physical assessment with a personal trainer. Fortunately, there are stretches, such as the Shoulder Cross-Arm Stretch that can help alleviate some of the pain and/or help prevent shoulder issues from occurring when you are doing exercises like the Chest Press or a Push-Up. This stretch is an exercise that will help benefit you along with corrective strength exercises and a well planned program, so you are not doing the same pressing motions too much.
Here is how you do the Shoulder Cross-Arm Stretch:
Start with your left arm. Grab your left arm with your right forearm slightly above your elbow, Use your right arm to slowly pull your left arm across your body. This stretches your side deltoids and rear deltoids. Keep your arm at about chest height. Hold for 15 seconds, then switch sides for your warm up. Hold for 30 seconds when you cool down. You can do this stretch several times a day even if you are not working out.