Originally Posted by Chas Tennis
That video has some great demos of what I believe are some of the important components of the serve. His demos seem to bring out the relaxed arm motions. I'm going to try his demos. Especially the video seems to show how supination would naturally come into the service motion.
Two things that could be improved -
1) For those who would imitate his body position, in my opinion, he keeps his shoulders too level. That orientation differs from the hitting shoulder high by lateral trunk flexion as recommended in the Ellenbecker shoulder video on minimizing impingement risk.
2) He also - as in nearly all serve instruction videos - does not mention by name or identify internal shoulder rotation and the prominent part ISR plays in developing racket head speed on the serve. Some instructors call the motion pronation but still do not clearly describe it.
How many instructor clearly understand ISR - whether they accept that view or not - and, if so, why do they hardly ever specifically mentioned ISR?
Is there a single instruction video where the instructor clearly explains how ISR works? Even if the motion is misnamed 'pronation'?
Thats not how the guy teaches. You are over analyzing it IMO.