Hewitt backhand?

[brett701]

If we assume this is true, it does not seem to rise to the level of a Biomechanical flaw.



This is what the poster said - my question was why?

Maybe, he means because it is an error in the stroke. A biomechanical flaw sounds a bit strong of a term to me.

[brett701]

I guess I’m not clear based on your analogy whether you are making an inertia argument (the swing leg of the sprinter) or a range of motion argument (the driving leg of the sprinter) – while radically different, either could work in the right circumstance as part of the answer.

As to whether the straight bottom arm is a net advantage to racquet speed (power) or not, the contact configuration needs to be taken into account. Based on my experience and logic the straight position at the start of the forward swing would have the following effect based on contact organization:

Straight/Bent: net benefit to contact racquet speed.
Bent/Bent: net detriment to contact racquet speed.
Straight/Straight: could go either way.

Because these different configurations significantly alter the way the joint rotation components contribute to racquet speed, some (so) targeted thought may shed light on this summary. The related issues of joint range of motion, muscle conditions, muscle development and type, etc. need also to be considered in this context.

In other words, full explanation would require a full article with quantitative information, pretty pictures, and so on – an article I hope to do in the not too distant future. At that point you can decide if my conclusions are valid or bunk.

Until then, I like the direction of your thinking (at least what I think you are saying).

THe analogy is not perfect and it does have many flaws. I just wanted you to understand my line of thought. I think that we are on the same page. However, your page may be a bit more advanced. My terminology is not quite at the level of the biomechanist, but i definitely have thought about many different strokes and why things are for a LONG time. The best part, im still learning at a rapid rate and to me... this is awesome.

[jktraverso]

It must just be me due to the lack of response, but I don't understand why it is a Biomechanical flaw, nor why it would reduce racquet head speed (at contact?) - please enlighten.

The "power drain" is caused by the locked elbow removing that lever from the kinetic chain - as energy is transferred through the levers it accelerates, remove a lever and you lose the enhanced acceleration. Imagine slapping a heavy bag as hard as you could. Would you do it with a locked elbow, or would you let the elbow be flexed to add "snap"?