Raise your arms to a horizontal position like chicken wings, and put dumbbells on your elbows to maintain your posture, which can effectively strengthen the endurance of shoulder tendons and protect your shoulders.
It is also a good exercise to keep the upper arm level, hold the dumbbell in hand and swing the arm slowly with the lower arm.
Buying a pitcher's strength training belt for slow-motion pitching is a training method often used by professional teams.
In addition, the ball speed is mainly determined by the speed of forearm and wrist. It is easy to get hurt by using shoulder strength to improve the speed of the ball.