What is ISR? Part 1: The Serve

[johnyandell]

Would love to get your thoughts on my latest article, "What is ISR? Part 1: The Serve"

[doctorhl]

Great article. The explanation between forearm pronation/supination and shoulder internal/external rotation on the serve is particularly good. The shoulder action drives the forearm action. So the sequence of shoulder action to forearm action will be undergirded by the amount of range of shoulder motion and the large percentage contribution of shoulder rotation contraction. The amount of wrist flexion/extension, radial/ ulnar deviation throughout the serve plays a minor role and is more of style than substance as John explains.

[doctorhl]

Of course, knowing the joint actions and the ability to sequence them, even with good range of motion, are two different animals. "I know but I do not feel".

[johnyandell]

Yep most people don't need to know... some just want to...

[tennisskip1515]

John, I'm curious to know what you think about Sampras' serve vis a vis wrist snap. Checking the archived vids it seems my memory of his motion – propelling certainly one of the greatest ever serves – is correct and he definitely exhibits a flexion of the wrist as the last lever action in his serve. Just curious, not challenging.

[johnyandell]

Skip,
The debate that will never die! No doubt that Pete's wrist--like all good servers--goes from laid back at the racket drop to neutral at contact. I am with Rod Cross on this--the racket is throwing the wrist. After contact you don't see the wrist flex forward past neutral. That would cut off the critical ISR.