Ulnar Deviation - I Just Don't See It

[rosheem]

In Brian Gordon's article, he says that ulnar deviation (motion of hand in direction of pinky finger) occurs during the upward swing just prior to contact and is a motion-dependent effect of elbow extension. He uses a clip of Agassi as an example.

The new Federer clip supports my theory that there is very little, if any, of this ulnar deviation occuring in most of the top servers. I think Agassi is an exception and not the rule.

But I think Brian might be right about the motion-dependent nature of ulnar deviation, and I've been using that to help improve my arm action. I found that I've been using active muscle contraction to move the hand across the ball in an attempt to create spin. I believe this interrupts the natural flow of energy in the serve and makes it more difficult to get the most out of the internal shoulder rotation and pronation movements. It also makes it nearly impossible to achieve the checkpoint in the serve where the hitting surface gets inverted just after contact and faces out and up.

In fact, I wonder if there is actually some kind of inhibitory action going on to prevent this ulnar deviation. Try it. In order to achieve the same post-contact checkpoint of the hitting surface flipping over and out, the elbow must naturally rise and roll over when the wrist is held steady. When this occurs in the context of the entire stroke, this "flipping" of the racquet face can be timed to occur at the moment the shoulder is snapping back from it's pre-stretched externally rotated state to internal rotation. This is how the weight and speed and leverage from the entire motion can all be put into the contact moment.

Quick disclaimer...trying to emulate the post-contact racquet orientation I've described might be hazardous to your health. Proceed with caution.

[BrianGordon]

Rosheem-

I guess the influence of the ulnar deviation to racquet speed is in the eye of the beholder - that is why I quantify it using 3D acquisition methods and marker sets to precisely define joint axes of rotation.

In this case, however, I see one of the clearest examples I've ever seen in video - this is because of the quality of the video - John is certainly way ahead of the game adding this incredible video technology.

Guess this is not surprising as he has been for a long time, and also because I was fortunate to be at that event and saw (and carried) the camera that shot that - quite a piece of equipment - go John! - and b.t.w. my back finally healed.

Anyway, my articles state that the influence of ulnar deviation is in the middle portion of the upward swing (not near contact). Despite the quality of the video, this joint axis is almost perfectly perpendicular to the optical axis of the camera during the period in question - this combined with some obstruction of the wrist transverse axes does make it difficult to see.

Still, the video frame rate allows me (at least) to clearly see that the racquet translation and rotation are heavily influenced by ulnar deviation in the middle portion (racquet long axis 15-20 degrees below horizontal to 15-20 degrees above horizontal) - exerting its contribution to racquet speed in tandem with the latter part of the elbow extension and just prior to internal rotation of the upper arm at the shoulder joint.

This is most evident by considering the vertical component of the racquet head speed at the time, a time when the late elbow extension (due to the orientation of the upper arm and relatively extended elbow configuration) and other significant joint contributory sources are linked more prominently to the horizontal racquet head speed components.

This fits perfectly with my quantitative research and that of others. It is clear that you really give deep thought to stroke mechanics and I enjoy your posts - in this case, I guess we just see different things - best - Brian

[rosheem]

Brian,

Thanks for taking a minute to reply.

At first, I was hesitant to even post on this topic because I didn't want it to seem like I was "calling you out" and challenging your quantitative work with nothing more than my observations to back up my theory.

Now I am glad I posted, because you really cleared it up for me. I just missed the part about the MIDDLE portion of the upward swing and I was only looking at the moment just prior to contact and right at contact.

When I was first learning the kick serve, I read a Jeff Counts article about "saving the hit" where he talks about waiting until the last moment to extend the elbow and pronate across the ball. I think I may have mis-applied this. I was actually holding the hand back so that I could use massive ulnar deviation just upon contact to spin the ball off the strings. Not good.

I'm not sure if that's a common problem or just common to guys like me who like to make things even more difficult for themselves.

Thanks for clearing it up.

I'm REALLY looking forward to more of your stuff. Of the many half-baked theories I have developed, I'm hoping some will be addressed in the forehand article you mentioned you were working on.

[tica1]

Are you working on a forehand article Brian?? Am really really looking foward to that!

[BrianGordon]

Rosheem-

Kind of thought we might be talking about a different portion of the upward swing - glad we could clear that up.

Tica1 -

Still in the planning and information acquisition stage - the diversity of approaches I want to assess requires data from a lot of different players - the project is getting closer to the top of my list though - we'll "get-er" done at some point.

[uspta2712824457]

Tica1 -

Still in the planning and information acquisition stage - the diversity of approaches I want to assess requires data from a lot of different players - the project is getting closer to the top of my list though - we'll "get-er" done at some point.

Just one more reason why Brian Gordon is great. At 6:28 Sunday morning, He is replying to post comments with a Larry "The Cable Guy" catchphrase.

All kidding aside, excellent post started by Rosheem. I love the feedback these technical posts get and how much we can all learn from each other.

[stumphges]

Still in the planning and information acquisition stage - the diversity of approaches I want to assess requires data from a lot of different players - the project is getting closer to the top of my list though - we'll "get-er" done at some point.

Great to hear. Looking forward to it!

[doctorhl]

“I'm not sure if that's a common problem or just common to guys like me who like to make things even more difficult for themselves. “

Rosheem: I went down that same road of manipulation of hand just prior to contact. The more I learn and read, the more it seems that motion dependent forces seems to warrant developing a “ natural” throwing motion and slight variances of ball location at contact will direct the racket path without affecting correct sequences of acceleration. Every beginning teenager I ever saw who had that natural serve sequence and acceleration had prior baseball or softball throwing experience as a child. However, significant alteration of timing of leg flexion and extension and toss location/ contact point to get the ball in the service court became an obvious issue. I guess I am in the camp who support some multi sport movement crossover for children pursuing single sports.

[glacierguy]

Slightly off topic, but when I was still young and playing, about 20yrs, I visited a friend in Framingham, Mass. and his brother was a college baseball player hoping to turn pro. We went to a park and messed about playing some baseball. As a tennis player, I could hit anything, and received some favourable nods. But when it came to pitching/throwing I was absolutely nowhere. I realised that there was a lot about throwing that baseball players had worked out, and I (and most Brits) had not.

[doctorhl]

Well, my year spent in Birmingham revealed that I my tennis/ baseball skills were of minimal help for striking/ pitching skills for cricket and and an embarrassingly lack of foot striking skills for football!!