Be wary of arm pain. In this age of year round baseball, its important to understand where your young pitcher is in his growth cycle.
There are two types of injuries, structural and muscular. Structural injuries are the worst and they include: growth plate separation injuries in shoulder and elbow and ulnar collateral ligament tears (tommy john surgery), elbow bone chips and labrum tearing in the shoulder. Muscular injuries include tendonitis, flexor tendon sprains, biceps tendonitis and front or back shoulder muscle soreness.
While overuse definitely correlates to arm injuries, poor mechanics is the absolute blame for pitching injuries. Poor mechanics from pitchers come from throwing a lower angles than over the top of the head. These lower angles create forces that snap the arm away from the body much like the spinning G-force stand up rides at carnivals.
It’s important to keep a running dialogue with your young pitchers to understand at all times how their arm feels. Kids that are competitive won’t usually tell you, so common sense would dictate that you use your best judgment, not the kids.
The problem with resting your pitcher is that no matter how long he rests for, every time he pitches he uses incorrect mechanics that continue to damage bone and ligament in the arm.