Shoulder impingement is one of the most common complaints in baseball, and it rarely announces itself all at once. It starts as something vague. A pinch at the top of the arm swing. Discomfort when you reach across your body. A shoulder that warms up slower than it used to. By the time it becomes something a pitcher actually tells someone about, it has usually been building for weeks. Understanding what is happening mechanically, and what a serious maintenance routine looks like, is how pitchers keep their shoulders working through a full season instead of managing problems that compound over time.