Tennis Serve - Racket-Forearm Angle (wrist). The server uses the racket at an angle to the forearm so that the ISR can create racket head speed. That forearm-racket angle during the final acceleration goes from about 90° to say 150° at impact. Then on to about 180°, arm-racket close to straight, right after impact. Probably if you let the racket go then it would be thrown upwards. ?
Baseball Throw - Forearm - Upper Arm Angle (elbow). Without a racket, a baseball player develops ball speed throwing using ISR in a similar way but by using an angle at his elbow. His elbow starts the final acceleration with an angle between his upper arm and forearm, it increases to a straight arm at release.
The amount of ISR that average throwers have learned to use probably varies a lot among individuals. Do you need to throw with stronger ISR for the throw drill to be effective in teaching the tennis serve?
Last edited by Chas Tennis; 09-25-2013 at 05:22 AM.