Kick Serve - Pronation vs. Ulnar Deviation

[seano10s]

John -

In my never ending journey to understand all technical aspects of strokes, can you or other knowledgeable members explain the "contact phase: of the kick serve. I know the elbow stays back and doesn't come around like on a flat or slice serve, but what is actually happening w/ the forearm/hand. Is there pronation or is it ulner deviation or is it a combination of both? Federer or Stosur seem to pronate, while Djokovic or Murray seem to ulnar deviate. What insight can you provide, thanks.

[johnyandell]

Seano,

Great question. I say that because you made me go look at some clips before I could answer.

Pronation is a technical term that actually just refers to the forearm and what we see in all these players is hand and arm rotation from the shoulder as a unit.

That's the way to conceptualize the rotation.

Ulnar deviation--that left to right flexing of the wrist is harder to see in Fed but seems there sometimes and I agree is more pronounced for Djok and Andy.

Still those two are still rotating the arm--just to a lesser extent.

Personally I like to emphasize the rotation and let the wrist take care of itself. I think trying to use the wrist--either to the right or forward cuts off the rotation.

Others????

[stotty]

Wrist and kick

Seano,


Personally I like to emphasize the rotation and let the wrist take care of itself. I think trying to use the wrist--either to the right or forward cuts off the rotation.

Others????

I agree about the wrist stuff. It's an uncoachable element. Coaching it causes confusion and, yes, leads to cutting off rotation.

It's odd, though, because when I analyse myself hitting a kick serve, everything is working a lot harder compared to my sliced or flat serve. Most of it feels like it's coming from the shoulder but also the arm and wrist a little. Probably because it's just harder to hit upwards. Probably top players do it much more fluidly.

[DougEng]

John -

In my never ending journey to understand all technical aspects of strokes, can you or other knowledgeable members explain the "contact phase: of the kick serve. I know the elbow stays back and doesn't come around like on a flat or slice serve, but what is actually happening w/ the forearm/hand. Is there pronation or is it ulner deviation or is it a combination of both? Federer or Stosur seem to pronate, while Djokovic or Murray seem to ulnar deviate. What insight can you provide, thanks.

I am going a bit out on a limb since people today classify the two service motions as the same. But I would argue there is a difference between an American twist serve and a modern kick serve. Therefore, despite the same kind of spin, it appears that different body parts are emphasized. The end result is the same, the ball moves left and bounces right. But the technique differs slightly. In the American twist, the toss is farther behind the head which allows the racquet to appear to come straight up but a modern kick is more 8 to 2 o'clock with less leaning backwards (back & hip extension + knee flexion). The American twist is a more violent-looking motion (e.g, Stosur) with an exaggerated follow-through far to the right and the modern kick is more moderate. It is a matter of style but the contact point can be different from old descriptions of the twist. In either, however, elbow extension is a part of the kinetic chain that must occur slightly before either pronation or ulnar deviation. Pronation is not regarded as a source of power [B. Eliott] but as for primarily alignment of the racquet face. As John and Stotty says, best to teach the upwards drive rather than the hand motions (Jeff Salzenstein also suggests it, differently, not to teach pronation during the kick since only some of it occurs). Simply the kinetic chain is a more powerful force than the wrist. The emphasis at the end of the upwards drive should be on elbow extension (when the racquet goes from butt up to contact). Furthermore, an improvement on popular teaching (to toss behind), you should toss the ball into the court, not behind the right ear. Tossing the ball behind the right shoulder or ear limits cartwheel effect, pronation and racquet head speed. Some pros toss directly over the head which may also limit ball velocity but is relatively sound. Tossing farther over the left shoulder promotes greater ball speeds, rather than just spin. If you toss more into the court (over the left shoulder), you will get more pronation simply because pronation occurs in the forward swing not when the ball is behind you). It is actually not difficult to kick the ball as I have some 3.5-4.0 and college females (average to ITF) learn to really kick the ball for the first time (as long as the grip and motion are sound). Seriously they can learn to kick in 10-15 minutes, which is ironic considering some of them have been playing for 12-15 years and 3-4 years at even international level. Often we think kick serves for women are rare; but it's more that they were not taught how to do it.