If you are a baseball or softball pitcher, you are automatically at risk for a shoulder injury. The explosive and repetitive nature of throwing will eventually cause an injury unless you take the proper precautions. Fortunately, maintaining a healthy shoulder is not difficult if you maintain your fitness throughout the season (Check out this baseball shoulder prehab routine).
When the season begins, you are probably at your strongest due to your off-season workouts. As the season progresses and you focus more on practice and games, your shoulder can begin to weaken if you don't proactively maintain your strength. Weakness puts more stress on the joint and can cause your mechanics to falter.
To keep your shoulder strong and healthy, you have to continue to develop your shoulder and back muscles. And the best way to do this is with exercises that are often performed in a rehab setting. They target the rotator cuff, shoulder, arm and upper back muscles, and improve mobility. Most of them can be performed at home or at the ball field with whatever weight is available, including elastic tubing, dumbbells or even your body weight.
Try doing this shoulder workout once per day to help maintain your strength during the season. When performing shoulder exercises, make sure to use proper form. If you perform an exercise incorrectly, you might do more harm than good.
Watch this video for a demonstration of the above exercises.
Watch this video for a demonstration of other shoulder injury-prevention exercises.