Originally Posted by LeeD
Yes, you of the 85 mph first serve telling someone not to pronate because it's of minor importance.
If pronation wasn't important to adding speed, everyone would serve with and eastern forehand grip.
Man, you are an old rude ignorant without fundamental tennis knowledge. You are talking about things you do not understand. Your "advices" can be sources of really bad injuries.
First, you know nothing about my serves, so be nice and shut up.
Second, pronation in the sense presented here is the action of forearm. At serves, it is not important at all.
The sources of kinetic energy of racguet's head at serves are listed below:
1. Shoulder velocity generated by leg drive and trunk rotation.
2. Elbow velocity generated by upper arm, elevation and flexion.
3. Wrist speed generated by forearm extension, forearm pronation and upper arm internal rotation.
4. Hand flexion.
These sources sums to ca. 70% of kinetic energy of the racquet's head. The rest is "generated" by optimal transfer of energy along the kinetic chain.
Forearm pronation is an important part of the kinetic sequence, but it is not a source of energy, you uneducated master. It is fundamental if you want to optimally use other parts of kinetic chain as sources of energy. That's why it's so important. Without pronation of forearm you do not have access to the real sources of energy.
The main sources of energy at serves are: shoulders (10-15%), upper arm (55-65%!!!) and hand flexion (20-30%). Source: my 30+ years of tennis experience, my knowledge of physics as a physicist and "Biomechanics and tennis", B. Elliot, Br. J. Sports Med. 2006; 40; 392-396; doi:10.1136/bjsm.2005.023150. And many other scientific sources you have never read.
I have strong feeling, LeeD, that you have no idea about real tennis, your tennis skills are very low and this forum is a kind of substitution for you.