Dr. Yeager is the “father” of back arm action in the swing and throw. No one understands it or teaches it better than him. Most coaches have never taught back arm action. All great players have great back arm action. The “BASEBALL-ARM” Trainer is an amazing baseball tool for hitting and throwing and helps the player develop elite level back arm action. Coaches loved it at the 2011 Nashville ABCA Convention. Is your player long when he hits or throws? Fix this problem with the arm trainer.