If you have pain, weakness, or restricted motion in your shoulder that doesn’t improve with rest, see a doctor. It could be a muscle tear or nerve problem.
Otherwise, start strengthening your shoulders and upper-back muscles with exercises that work one arm at a time. For instance, try the single-arm lat pull-down using a pulley handle.
And try this push-up: Assume the classic push-up position, bend your elbows to lower your body to the floor, and then push back up.
At the top of the move, push a little farther so that your shoulders push forward and your upper back arches. Then return to the start. Do three sets of 10 to 15 repetitions.
“This trains a muscle on the inner portion of your shoulder blade called the serratus anterior, which helps keep your shoulder blades properly aligned,” says Dr Steve Petersen, co-director of the shoulder-surgery division at Johns Hopkins school of medicine.