External Arm Rotation

[markus_vafaan]

Hello,

I want this thread to discuss:

The importance of external arm rotation in the serve.
How to improve external arm rotation.

anyone with or without knowlegde in this topic please submit your thoughts!

I have posted three pictures showing what external arm rotation is. So do you guys believe it is the secret behind a BIG SERVE? Roddick has a lot more external rotation than Federer and Roddick hits faster serves...

Interesting to note is that Javelin throwers who do have a similiar over head throwing action like the tennis serve often have huge external arm rotation capabilities!

According to Bob Prichard of Somax Sports, Roddicks external arm rotation is about 60 degrees but he has worked with a javelin thrower who had 90 degrees of external arm rotation.... IMAGINE HIS SERVE?? or those this matter?

And if External Arm Rotation is the answer to a bigger Serve how to we increase our own external arm rotation?

I am happy to hear answers and thoughts/ Markus

[johnyandell]

This topic is discussed in the Advanced Tennis articles on Roddick's and also Federer's serves.

[GregRyan]

Shoulder rotation

Bruce Elliot identified in a landmark 3D biomechanical study that internal rotation of the shoulder accounts for 54 percent of the racquet head velocity in power serves. Many exercise physiology studies have also shown significant increases in serve velocity with internal/external shoulder resistance exercises. I found a good link on the web that demonstrates many exercises for the shoulder joint. These are also excellent exercises for injury prevention that increased Range of motion and strength.

http://orthodoc.aaos.org/JonathanEFowMD/THROWERS%20TEN%20EXERCISES.doc

GR

[markus_vafaan]

Great Link GregRyan! Thanks big time!

Sorry Heath if it has already been discussed. Personally I believe that this is a huge part of the service and maybe should be even more discussed and talked about. For example we can discuss different exercises and stretches or whatever methods there are out there.

But if everything is already out there on the site then I am sorry and I will go back and look again.

Cheers/ Rasmus

[BrianGordon]

int/ext shoulder rotation

Hi All-

Internal rotation (twisting of the upper arm about the bone axis [humerus]) is indeed an important source of racquet speed at or near contact. I don’t know if 54% is the value exactly for several reasons (if interested see Gordon and Dapena, Contributions of joint rotations to racquet speed in the tennis serve, Journal of Sport Sciences, Jan. 2006; 24(1): 31-49) but regardless of the exact value, this rotation is critical to many high level servers.

And the internal rotation influence is largely determined by the external rotation amount and contractile conditions (another example perhaps of everyone’s favorite topic – the stretch shorten cycle). But experimentation should be incremental and somewhat cautious.

The body actions used to illicit the external rotation are critical here, and if done incorrectly, may create dangerous conditions for the shoulder and elbow complexes. Of course, as Greg points out, preparing the body for these loads will mitigate the dangers to some degree.

Another factor is that the external/internal rotation mechanics may be useless if the hitting arm/racquet segment configuration is not correct for that rotation sequence at the critical times, an important consideration for playing and coaching practitioners.

That is all I have for now, but soon I hope to provide a lot more information on this topic.