Announcement

Collapse
No announcement yet.

Wrist movement

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Did my homework

    Originally posted by johnyandell
    Kevin,

    Again you are focusing on one tree that didn't produce the forrest. I see that you want to understand all the details of the strokes. But controlling where the butt of the racket points for a few milliseconds is not going to be a productive strategy--in fact definitely the opposite.

    I'm not going to reproduce several years of work in one Forum post to try to convince you of the relative nature of some of these details. If you read the suggested articles carefully, then you will be more up to speed to discuss this--what you'll see is that if the players make certain common positions that's the key--not necessarily the complex and dynamic (to use Greg's terms) micro movements of the frame by frame patterns.

    John

    I did my homework and you are, of course, exactly right. I've also had the chance since then to video tape my strokes and to study more of the high speed videos that you sent. I've even attempted to make some changes in my forehand stroke.

    I have just re-read all of your articles on "Buliding the Modern Forehand" (except the two on Federer). How frustrating to see how much I had forgotten in just a couple of weeks. :-( However, I think I am also better able to understand them now that I've spent so much time on the site and with the high speed videos).

    I also see that you covered, in the articles, the fact that some professionals do slightly "flex" their wrists a bit on the forward swing (or it at least un-extend a bit), and that the ball sometimes forces the relaxed wrist back a bit at impact.

    Looking at the photo with the caption: [The hitting arm position stays the same, but as the racket rotates the grip becomes more extreme and the angle of the racket face naturally closes.] at


    it shows how the racquet face closes as the forehand grips become more extreme. With these pictures in mind, and seeing that all of the professionals have the racquet face closed just before starting the forward swing, I got to wondering how the guys with the more extreme grips get their racquet faces back to essentially vertical at impact. You may have explained this in the articles, but if you did, I didn't catch it.

    It looks to me like this is why the more extreme the grip, the more extreme the shoulder turn (forward) before impact. It strikes me that the "closed-ness" of the racquet face "squares up" or becomes vertical in different ways in different "hand/hitting shoulder" relationships. What I mean is, (I think) the hitting hand is further out in front of the hitting shoulder for the extreme grips when the face becomes vertical. If they hadn't turned their shoulders more by the time they had made contact, their racquet faces would be pointing well out to the right of their target. I may be all wet here. Maybe this also puts their forearms more straight behind the hand in the hitting position than the less extreme crowd, and maybe it *needs* to be since their palms are not as "behind" (instead, more "under") the grip as it is with the less extreme crowd. The following page shows the contact points across the grip styles, and it does look to me like Pete is making contact "less out front".



    I think the more extreme grips could also get the face both vertical and facing the target by swinging in a more steeply low-to-high angle. This would still allow the swing to be "from the shoulder" rather than resorting to any wacky wrist stuff. But, it looks (to me) like (and I believe John says) the typical (not low balls or sharply angled shots) stroke is not very steep for any of the professional forehands. That is, the hitting hand is only barely below ball height as it comes forward.

    I'm not clear on the "internal rotation" (pronation via the radial-ulnar joints?) occurring before impact. It seems to me that, if that were to occur prior to impact, then the "closed" racquet face in the backswing would become *more* closed, rather than squaring up to vertical. I suppose, too, that it's possible that the stuff going on within other joints could counteract that "closing". Still, in the slow-mo's that I've watched, it doesn't look to me like it happens until after the ball has left the strings.

    I think I am beginning to see why I've had such a terrible time controlling the trajectory of my topspin forehand for so long. It looks like all the professionals are swinging primarily in the horizontal plane with their swings, with only a slight low-to-high vertical component.

    Prior to learning that I needed a "unit turn", it looks like I've been trying to swing in primarily a vertical plane. No matter *which* forehand grip I used, I was only going to have a near vertical racquet face for a *very* short period of time. I was trying to keep my racquet head going "down the line" *too* much.

    Interestingly, in "The Physics and Technology of Tennis", they point out that a few degrees left or right error in racquet face angle only throws the shot off a relatively few inches left or right on the opposing baseline, while having the racquet face pointing too high or too low at impact (opened or closed to veritcal) by only a very few degrees makes the difference between hitting it into the court or into the fence or net.

    It looks like I haven't had a prayer. I think that is also why I've been so hung up with the wrist stuff. Since looking at my recent videos, I've not only added in the "unit turn", but I've also worked on doing away with most of the wrist and forearm stuff and am trying to do as much as possible with just my shoulder joint. The "quality" of the topspin that I now generate feels totally different, and the trajectory is in a much more narrow range.

    I also see now that my one-handed topspin backhand (which *hasn't* been a problem) has been executed primarily in that horizontal plane.

    I've mailed a little video of my strokes to John. I look forward to his and other critiques and other suggestions. I'm hoping that John will like my lack of a "loop" in my forehand backswing. :-)

    While I'm thinking about it, I wonder if many others have tried this. Once I realized that I had gone *past* (more extreme) the Eastern grip on my backhand to having my main index finger knuckle over the eighth bevel rather than on the top bevel, I realized that I could use that same grip for my topspin forehand if I switched to a semi-Western (from Eastern) - but use the *same* side of the strings for both shots. It wasn't much of problem to make the forehand change since my forehand sucked, anyway. :-)

    Kevin
    Savannah
    Last edited by mntlblok; 02-05-2006, 10:09 AM. Reason: typos and clarity

    Comment


    • #17
      Although the thread seems to have taken a different direction, here's a great resource for joint movements and their associated scientific terms.



      Originally posted by johnyandell
      It's like the questions Vin Miller used to mail me about wrist on the serve. When we saw the video of his motion we discovered some other fundamental issues that were the key to him making real improvement.
      Doh!

      Comment


      • #18
        [QUOTE=vmiller] here's a great resource for joint movements and their associated scientific terms.



        How could they have left out the jaw joint??!!

        Kevin
        Who knows a bit about the TMJ :-)

        Comment


        • #19
          Article

          Originally posted by GregRyan
          I am not sure what the point is about the movement of the butt of the racquet?
          [snip]
          Here is an article explaining Bernstein's concepts on the complexity of human movement.

          http://www-anw.cs.umass.edu/~mtr/papers/VanEmmerikR04.pdf#search='bernstein%20russian%20sc ientist%20motor%20control'
          I guess I'm trying to compare that sudden change in direction (and a similar move in the service motion in a vertical plane) to what happens when a whip is cracked - but with the *other* end of the racquet. Maybe I should have referenced the "tip" of the racquet head instead of the butt. I don't know the physics of what happens when a whip is cracked, but if *you* understand the article above (and I suspect that you do), then you probably understand what happens when a whip is cracked (or when a fly rod is cast). Can that sudden change in direction by a player like Roddick or Nadal be compared with a whip crack? (I know that they don't break the sound barrier).

          I understand that this aspect of the topspin forehand is not critical. Just curious as to whether anyone *knows* what the implications might be for the racquet head going through so many "radians" so quickly.

          BTW, I sorta get "some" of the gist of the article, but it is obviously way over my head, and, I suspect, way over the heads of most of us mere mortals. I *do* get a kick out of being reminded of just how smart some folks are out there and see it as an awesome wonder. My hat is certainly off to you. :-)

          And, the article does make it abundantly clear just how difficult it would be to scientifically quantify what is going on in a tennis stroke. I think they were trying to say that studying human biomechanics scientifically is not as difficult as it first appears - and maybe it's not. But it sure looks like it is difficult enough that it won't happen to any great degre in *my* lifetime.

          Kevin

          Comment


          • #20
            Double bend

            Originally posted by mntlblok
            I've mailed a little video of my strokes to John. I look forward to his and other critiques and other suggestions. I'm hoping that John will like my lack of a "loop" in my forehand backswing. :-)
            [snip]
            While I'm thinking about it, I wonder if many others have tried this. Once I realized that I had gone *past* (more extreme) the Eastern grip on my backhand
            Looking at more video today, I realized that I also don't use the double bend in my backswing on the forehand. My arm was locked straight at the elbow. Tried the double bend today and it made my timing much easier. Another easy change to make.

            Also noticed that my upper body falls back on my one handed topspin backhand - much as Henin does. I wonder if it is due to my goofy grip. Wonder if Henin uses that grip. I get my weight shifted to my front foot. It's just the upper body that seems to fall back - which would seem to allow the more closed grip position to have a better chance to become vertical at impact. Video is on the way.

            Kevin
            Last edited by mntlblok; 02-04-2006, 06:14 PM. Reason: typo

            Comment


            • #21
              Last body segment in summation of forces

              What we are seeing at the butt of the racquet is the final segment of the body (hand) that is transferring energy to the racquet. The hand and wrist segment is moving extremely fast (I am sure Brian Gordan or Bruce Elliot can give examples in radians/sec), but this is because energy has transferred from other segments of the body. My point is that the stroke is a full body movement and no one component dominates over another. I try to emphasize all critical biomechanical movements of the stroke. If one component is missing, none of the movements can be efficient.

              GR

              Comment


              • #22
                Your pictures were informative, but I think a vital key to linking the physiological aspects to actual tennis lies in Bollitieri's article in the Famous coaches section. In his forehand article, he gives three very useful tips - pull the racket out of the chute, point the butt at the ball like a flashlight, and have your elbow follow a diagonal trajectory.

                Bollitieri's tips are simple which makes them easy to transfer to actual tennis. This thread helps to consolidate some of those tips into an anatomical understanding, but I'd like to see more of those simple, easy to remember tips in order to improve my forehand.

                I'd really love to see Bollitieri do an article on the backhand/backhand slice in the future. His advice is tremendously helpful.

                Comment


                • #23
                  Originally posted by GregRyan
                  I try to emphasize all critical biomechanical movements of the stroke. If one component is missing, none of the movements can be efficient.

                  GR
                  I agree. And if the footwork doesn't place all this biomechanical stuff in the right place, then its often a moot point. Yet, this type of thread greatly helps understanding strokes which may or may not lend to better hitting.

                  The best thing I ever did to improve a groundstroke was:

                  1.) Improve footwork and put as much mental energy into properly placing my body in relation to the ball as I do into hitting the ball

                  2.) Steady my head and eyes

                  3.) Wait longer before very rapidly accelerating my racquet (at the last possible moment) so to speak, thus accelerating rapidly over a relatively short path, regardless whether I am using a large looping swing or a short compact swing regardless whether I am hitting flat or with varying degrees of top spin, regardless of which grip I am using.

                  Comment


                  • #24
                    Visual tennis

                    Just back from volunteering for a week at the Delray Beach tournament. What a fun time. I'm watching the second by second update on line for the current match's scoring.

                    I was able to watch the players hit their shots with a totally different eye after studying the tennisplayer.net site. I left home with a better shoulder turn for my forehand, but still felt affected or stilted when I tried to make myself actually stick my left arm way across my body as part of the turn.

                    After watching every last one of those guys do exactly that, over and over and over, it quickly became second nature when I got home this afternoon and hit the courts. That unit turn, along with my new double bend, has pretty much taken care of the rest of my thirty of so swing thoughts that I used to need to get a ball over the net and into the court from the forehand side. :-)

                    Watching all those guys' strokes also cemented in my mind that it's time to learn to hit more "through" the ball. Tennis is getting to be a lot more fun.

                    The timing of my work shifts worked out that I didn't get to see Agassi practice, but had ample opportunity to see Tommy Haas up close. Boy, is that guy smooth. I now have a picture of him in my mind each time I stroke a forehand.

                    I'll be busy for the next few weeks going through the several thousand photos that I took. :-)

                    Kevin
                    Savannah

                    Comment


                    • #25
                      Now that is a positive post!

                      Comment


                      • #26
                        Dynamic slot?

                        Originally posted by johnyandell View Post
                        Kevin,

                        Again you are focusing on one tree that didn't produce the forrest. I see that you want to understand all the details of the strokes. But controlling where the butt of the racket points for a few milliseconds is not going to be a productive strategy--in fact definitely the opposite.

                        I'm not going to reproduce several years of work in one Forum post to try to convince you of the relative nature of some of these details. If you read the suggested articles carefully, then you will be more up to speed to discuss this--what you'll see is that if the players make certain common positions that's the key--not necessarily the complex and dynamic (to use Greg's terms) micro movements of the frame by frame patterns.

                        John
                        What if one calls it a dynamic slot?

                        kb

                        Comment


                        • #27
                          The butt cap still wouldn't point at every ball. Great concept though--the dynamic slot that is.

                          Comment


                          • #28
                            Kevin, have you read Brian Gordon's articles on the ATP forehand? I think it answers your questions about the role of the wrist. The type 3 forehand I think has what could be called a passive wrist. With this passive wrist, as the forward movement to ball impact is initiated with the accompanying external shoulder rotation, the wrist flexion occurs and one kind of feels the centrifugal force of the racquet head doing the work, kind of throwing the racquet head to impact. As John mentioned, Maria is not a model for this action.

                            Comment


                            • #29
                              Racquet snaps the wrist thread...

                              Originally posted by stroke View Post
                              Kevin, have you read Brian Gordon's articles on the ATP forehand? I think it answers your questions about the role of the wrist. The type 3 forehand I think has what could be called a passive wrist. With this passive wrist, as the forward movement to ball impact is initiated with the accompanying external shoulder rotation, the wrist flexion occurs and one kind of feels the centrifugal force of the racquet head doing the work, kind of throwing the racquet head to impact. As John mentioned, Maria is not a model for this action.
                              That's right stroke…passive as a hinge. Remember "Racquet Snaps the Wrist" thread.



                              Originally posted by don_budge View Post

                              A poster by the username of "erbr" posed the question and this is what I wrote for an answer.

                              The Wrist is a Hinge

                              Am I the only person who considers pronation as a natural biomechanical occurrence?-erbr

                              Knowledgable tennis players and golfers all over the world agree with you. When teaching the serve I sometimes make a bit of an oblique reference to the serve being similar to an upside down golf swing. Instead of teeing it up on the ground, we attempt to tee it up in the air. To begin with some of the similarities are the take away, the backswing, the transition between backswing to forward motion and the "release" of the wrist(s) which deliver the racquet or club to the ball...it even helps to "waggle" the racquet a bit in the preserve routine. The action of the wrist(s) is perhaps the most fundamentally important aspect of swinging a tennis racquet or a golf club (Ben Hogan certainly agrees with you)...or to swing anything else for that matter. This goes for all shots...long or short, fast or slow...not just the serve. It is also perhaps the most difficult aspect of swinging to convince a tennis or golf student of...it is a matter of swinging, not hitting. Getting too "wristy" even with short putts is the kiss of death, but that being said...you still must swing the putter.

                              I describe the function of the wrist...or "handled" as it is called in Swedish...as that of the hinge on a door. One never has to consciously think about applying the wrist in the swing of the racquet or the club, but you must let it do what it most naturally wants to do...and that is to swing smoothly with all of the centrifugal energy that the mind/head (the idea behind the shot intended to play), the feet and legs, the hips and body, the shoulders and finally the arm have created. The action of the wrist is a product of all of this and it's job is to transfer all of that action into the face of the racquet. It's really such a simple thing...ha ha. But it's best not to talk too much about it...or to think too much about it either, for that matter. Better to concentrate on footwork and getting into position and just letting "the thing" happen.

                              Once the wrist(s) take over...delivering the payload feels a bit like "slamming the door".

                              Everyone always talks about the thumb being such an important digit for homo sapiens. But the wrist for tennis players...and for golfers, is the joint that makes it all possible. Superb question erbr...and I agree with you.
                              The wrist is the conduit through which the sum of all of the energy is transferred into the racquet head and therefore the ball.
                              don_budge
                              Performance Analysthttps://www.tennisplayer.net/bulleti...ilies/cool.png

                              Comment


                              • #30
                                Originally posted by johnyandell View Post
                                The butt cap still wouldn't point at every ball. Great concept though--the dynamic slot that is.
                                It's been ten years, but I think my point was that the butt cap doesn't just point forward (or towards the ball), but out to the right - and *definitely* as a passive thing ("snap" or "whip" or maybe even "flip"), as I also pointed out that when I tried to just put the racket into that position that it was painful to try to just hold it there. I had no idea about the stretch shortening cycle nor that the upper and lower arm segments were pulled clockwise prior to snapping back counterclockwise for the "doorknob" or "wiper" thing.

                                But, the rapidity with which the racket face then changes direction and travels through such a long arc (lots of angular momentum) struck me as just *having* to be of importance.

                                I stopped in to see Brian G, again, this past summer on one of my dive trips and learnt that tennisplayer.net was the only place where he's published on the topspin forehand. January is my "catch-up" month, so here I am.

                                I *think* that I recall his telling me in the past that he didn't think that the loop was necessary for the forehand and that he preferred a straight take-back. IIRC, then it looks like maybe he's changed his thinking.

                                Coincidentally, I played with and against (doubles) this morning a guy with as good a topspin forehand as I've ever been on the court with, and he got to that "dynamic slot" without a loop. I even made him let me video it with my iPhone slomo. Do I have to ask him in order to post it on YouTube you reckon?

                                kb

                                Comment

                                Who's Online

                                Collapse

                                There are currently 11099 users online. 6 members and 11093 guests.

                                Most users ever online was 139,261 at 09:55 PM on 08-18-2024.

                                Working...
                                X