Announcement

Collapse
No announcement yet.

Interactive Forum: Hand and Forearm Motion

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

  • #16
    Federer wrist snap

    I beg to differ if still photo 2 of Federer is prior to contact. It clearly shows that the wrist has flexed greatly from photo 1. In photo 1 it is layed back. In photo 2 it has flexed almost to neutral.

    Besides the if you look from above the flex is not moving the racquet right to left which would destroy all control. It is moving it up and down. The plane of the racquet stays perpendicular to the flight path and the combination of arm pronation,flex and radial deviation moves the racquet head upward. This adds a lot of spin while allowing the swing plane to be through the ball.

    Edit: It appears that photo 2 is about a 1/10 of a frame after contact. There is no way the wrist could fully release in the small amount of time between contact and the photo. I believe that if we had a higer speed sequence we could see that it was released or releasing at contact.
    Last edited by cyberhound; 11-07-2006, 11:04 AM. Reason: Review of frame by frame

    Comment


    • #17
      I feel that the stretch shortening cycle is initiated by having the wrist laid back at the bottom of the loop and abruptly rotating the hips forward.

      Comment


      • #18
        Originally posted by gzhpcu
        I feel that the stretch shortening cycle is initiated by having the wrist laid back at the bottom of the loop and abruptly rotating the hips forward.
        The wrist should be relaxed and neutral at the bottom of the down swing before releasing the hips. If its already laid back the reflex doesn't occur. The shortening is an unconscious reaction to the quick stretch. If you consciously lay the wrist back prior to hip snap, everything is static and you will have to consciously bring it back.

        Comment


        • #19
          Originally posted by cyberhound
          The wrist should be relaxed and neutral at the bottom of the down swing before releasing the hips. If its already laid back the reflex doesn't occur. The shortening is an unconscious reaction to the quick stretch. If you consciously lay the wrist back prior to hip snap, everything is static and you will have to consciously bring it back.
          The movement I mean is ulnar deviation of the wrist and supination of the forearm: not more laying back of the wrist.

          Comment


          • #20
            Originally posted by cyberhound
            I beg to differ if still photo 2 of Federer is prior to contact. It clearly shows that the wrist has flexed greatly from photo 1. In photo 1 it is layed back. In photo 2 it has flexed almost to neutral.
            Well, as John outlined in the articles, Federer can hit with different hitting arms and different wrist positions, so it really depends on what kind of forehand he's hitting.

            Comment


            • #21
              Stretch shortening

              Originally posted by gzhpcu
              The movement I mean is ulnar deviation of the wrist and supination of the forearm: not more laying back of the wrist.
              That's what I mean as well. If the wrist is relaxed and neutral at the bottom of the downswing, the palm is basically facing down and the forward momentum generated by the hips resisted by the inertia of the racket will cause mostly, ulnar deviation and supination.

              I think it can work with the wrist layed back (flexed up) but I think it works better if the arm and wrist are more relaxed. I think the muscle tension of laying the wrist back defeats it to some extent.

              In any event, I think its essential that the racquet be on the front side of the body with the head as much in line with the ball as possible before the hip snap.

              Comment


              • #22
                RE: wrist snap

                This is a beautiful super slo mo of federer's forehands, shot from the side view.



                Pay particular attention to the second forehand he hits, as this is a side view, and thus, less deceptive.

                Also, check out this





                The wrist appears to be laid back at least until the ball has left the racket. Watch it frame by frame. I don't see any flexing of the wrist foreward in the impact zone.

                From this view, one can say that his wrist is definitely not neutral, or even close to neutral (if by "neutral" you mean the hand is in a straight line with the arm). The wrist definitely does not appear to be released, or releasing through impact. On the contrary, it almost appears that has the ball collides with the racket, his wrist gets slightly more laid back for a very short duration. His wrist appears to release when his hand is about level with his left shoulder.

                However, someone else pointed out that Federer hits many different forehands--Meaning the degree to which his wrist is laid back at impact may vary, but I've never seen Fed with a neutral wrist, IF by neutral wrist you mean the hand being straight in line with the wrist. There is always some degree of lay-back. I think you'd agree with me on that.

                In fact when I re-watched the first video (posted above), the first forehand in the sequence appears to have a less laid back wrist at impact, but again, the angle may make it deceptive, so I don't know for sure. I think viewing the forehand from the front is deceptive. to really see the relationship of the hand to the forearm, you need a super slo mo shot seen from the side.

                Best wishes,
                Evikshin
                Last edited by evikshin; 11-07-2006, 02:48 PM.

                Comment


                • #23
                  Great thread.

                  The two important frames, already identified, are the one just before contact and then contact. Generally called "hitting late", or "delayed release". Common in many sports -- golf, tennis, hockey, baseball, etc.

                  Simple physics. The grip end (doesn't matter which sport) "stops" or abruptly changes direction setting the racquet head in circular motion. See centripetal force at http://en.wikipedia.org/wiki/Centripetal_force.

                  Ben Doyle, a well known golf instructor (near Pebble Beach), calls the frame just before contact, "courage". Very, very difficult for club-level players to trust the feeling of holding-off to the last possible micro-second.

                  Conventional tennis language, in part, describes the above with words like, "going for your shot", "pushing", "tightening-up", "tentative", etc. Also, and I'm not sure why, the correct bio-mechanics of "hitting freely" really improves and frees-up movement.

                  Get video tape, and see when you start to release. Chances are good it is way before the frame before contact.

                  Most Women pros (except Henin-Hardenne) and most juniors (see Rick Macci video this), set the racquet with the butt pointing forward very early.

                  For me personally (took up golf and tennis late in life), this issue is one of my biggest problems. Here's what I do:

                  * Enough of a backswing or wrist rotation to get the butt pointed forward before or just after the start of the forward swing.
                  * Now, do you "pull" (with hips, abs, and shoulders) the racquet forward, or "push", or a combination of the two. Here is where it gets tricky. You need to experiment and decide for yourself. Slow motion video is not helpful here and can actually be harmful, because the film doesn't show the actual pressures and exertions and can be mis-leading.
                  * I feel that I am "pulling" the butt forward toward the net. I realize the pros often point the butt with more backward rotation at the ball, but I settle for the feeling of pulling toward the net. I can sense the butt pointing forward and the racquet facing the side fence.
                  * Now I ask, how the h*ll is the racquet face going to square up in time. Same problem with my serve. The answer is, have courage. You have to learn to "trust" it.
                  * The next key feeling for me which I can sense is that my shoulders have rotated back to square (facing the net), but the racquet now feels like it is being pulled from behind me. Now I have to really fight the tendency to release early. I try to sense that my hand, with racquet butt still facing forward has at least pulled even with my body. This is my go position and the last one where I feel any sense of control.
                  * Form here, I let it go, no more conscious control. If all goes well up to here, my hand can't travel any further (my feeling), but in fact it has moved just in front of my body, it can't really go naturally much further, and the racquet head then swings around and "snaps" into place at contact (the feeling I get when it works).
                  * Often times, if I want to add more body weight, I can "wedge" the racquet into contact (instead of a snap feeling) and apply a pushing exertion (with my body and right shoulder) to the ball to add a little extra drive, and less of a whip action. I'm essentially wedging the racquet between my body/shoulder and the ball at contact.
                  * Important point: the proverbial contact out front "just happens"; it is a position you are going through as result of earlier exertions and not a destination in and of itself.
                  * I'll use wrist and arm rotation in varying amounts for different spins, or to "fight the ball off" when my footwork doesn't allow me the time to get the ball in the strike zone

                  Hit a ton of balls and play practice matches (ladder matches where losing doesn't knock you out of the tourney are good) and stay with it, no matter what the score, win or lose. You will be surprised how fast you will climb in levels and rankings.

                  -- Jack

                  Comment


                  • #24
                    Federer/Nadal open FHs

                    Originally posted by johnyandell
                    Roger Federer and Rafael Nadal are at the opposite end of the grip spectrum, as well as styles of play.

                    But what do their forehands have in common?

                    Take a look at the hand and forearm motion in these two animations, as well as the frame by frame movies below.

                    See what you discover, and tell us what you think!

                    Federer



                    Nadal

                    Federer and Nadal have vary similar FH biomechanics in their wide, open stance low heavily topspin shots. Their finishes, really their follow-throughs, are different because Nadal uses an extreme western grip but makes contact close to the body. This forces a Sampras-like follow-through around the head. Federer uses a semi-western to western hybrid grip. He makes contact more in front of the body and ends with a more ordinary, so-called millenium follow-through wrap around the shoulder.

                    Fred Carrillo, Hilton Head Island, SC

                    Comment


                    • #25
                      Originally posted by evikshin
                      RE: wrist snap

                      However, someone else pointed out that Federer hits many different forehands--Meaning the degree to which his wrist is laid back at impact may vary, but I've never seen Fed with a neutral wrist, IF by neutral wrist you mean the hand being straight in line with the wrist. There is always some degree of lay-back. I think you'd agree with me on that.

                      In fact when I re-watched the first video (posted above), the first forehand in the sequence appears to have a less laid back wrist at impact, but again, the angle may make it deceptive, so I don't know for sure. I think viewing the forehand from the front is deceptive. to really see the relationship of the hand to the forearm, you need a super slo mo shot seen from the side.

                      Best wishes,
                      Evikshin
                      I would agree that there is always some degree of layback. When I say neutral, I mean an unstressed position that is close to a handshake position which has some degree of layback. Also, I don't mean wrist flexion which to me means that if the the hand is pointed away from you as if to shake hands, bending the wrist so the palm faces you. I think the wrist position is used to control the direction of the ball. Severely laid back if you are in the center of the court or the backhand corner hitting to the backhand. Almost in line with the arm if you are wide to the forehand corner hitting crosscourt.

                      Even so It seems in the videos, that just after the motion that causes the racquet snap back that the wrist does flex forward somewhat before impact. It does seem that the angle between the wrist and the arm reduces to some degree from maximum deflection. Maybe its a visual trick.

                      The wrist and arm movement that I'm refering to is the change from ulnar deviation to radial deviation coupled with forearm pronation that moves the racquet from low to high through the contact zone in a plane perpendicular to the contact. The follow through of that motion is the arm lifting and turning over and the wrist flexing after contact. but to get the follow through you have to start it earlier.

                      The whole action is similar to throwing a frisbee with the forehand upward at a 30 degree angle.

                      The drill that is used to teach this is as follows:
                      Stand inside the service box facing the net. Hold racquet with forehand grip. Hold racquet in front of you with face parallel to ground. Hitting strings facing the ground. Have partner feed a ball to your forehand hitting position. Wait till the absolute last second. Quickly supinate the arm and ulnar deviate the wrist followed by pronating the arm and radially deviating the wrist to hit the ball over the net. With a little practice you can control the ball very well and put it were you want. Not my drill by the way, it comes from a coach on the pro tour so I probably shouldn't give it away. Incorporate this into your swing and you've got a federer-rafa-roddick-safin-like forehand.

                      A lot of this is difficult to see. Has anyone ever seen a racquet impart topspin (roll the ball). The ball is on the strings for so short a time the racquet imparts an unbalanced torque on the ball and the spin starts after it leaves the strings. (my opinion).

                      Regards,
                      Last edited by cyberhound; 11-08-2006, 03:33 PM. Reason: Clarity

                      Comment


                      • #26
                        Hand and Forearm Motion -- Fed vs. Nadal

                        Both demonstrate the degree to which tennis strokes have come to emulate pure throwing mechanics. The wrist and forearm motions are precisely what one would expect if the objective in striking a tennis ball was essentially to "throw the racquet" into and through the ball. The body effectively whips the racquet into the ball through a kinetic sequence of ballistic muscle movements that begins with large proximal muslces (legs, pelvis, trunk), and moves outwardly through the shoulder, arm, and wrist, the last to get into the action. The wrist lay-back results from racquet head inertia and a relaxed hand and forearm, and it is whipped into and through the ball not through palmar flexion, but through the angular momentum generated by the preceding leg, pelvis, trunck, shoulder, and arm. The only surprising thing to me is the extent to which Fed's hand faces down at full backswing extension. In view of the general sidearm motion he makes through contact, I suspect this was unnatural and learned and has only become beautifully integrated into this swing through considerable work.

                        cms56

                        Comment


                        • #27
                          Hand and Forearm Motion

                          Originally posted by cms56
                          Both demonstrate the degree to which tennis strokes have come to emulate pure throwing mechanics. The wrist and forearm motions are precisely what one would expect if the objective in striking a tennis ball was essentially to "throw the racquet" into and through the ball. The body effectively whips the racquet into the ball through a kinetic sequence of ballistic muscle movements that begins with large proximal muslces (legs, pelvis, trunk), and moves outwardly through the shoulder, arm, and wrist, the last to get into the action. The wrist lay-back results from racquet head inertia and a relaxed hand and forearm, and it is whipped into and through the ball not through palmar flexion, but through the angular momentum generated by the preceding leg, pelvis, trunck, shoulder, and arm. The only surprising thing to me is the extent to which Fed's hand faces down at full backswing extension. In view of the general sidearm motion he makes through contact, I suspect this was unnatural and learned and has only become beautifully integrated into this swing through considerable work.

                          cms56
                          We are saying almost the same thing in different ways. There is a beatiful slo-mo video from a competitor's web site (tennis1) that someone downloaded and emailed to me that clearly shows Federer throwing and whipping the racquet at the ball with an arm that looks like rubber.

                          I need John Y's opinion if I or he will get in trouble if I upload it. It is really interesting.

                          Comment


                          • #28
                            Thanks for asking. No we can't upload that clip, as that would violate the copyright!


                            Why don't you look at the Federer high speed clips on Tennisplayer in the high speed archive. Post the URL that is closest to what you are talking about, and I'll do the code and insert it in a Forum window.

                            Comment


                            • #29
                              Originally posted by johnyandell
                              Thanks for asking. No we can't upload that clip, as that would violate the copyright!


                              Why don't you look at the Federer high speed clips on Tennisplayer in the high speed archive. Post the URL that is closest to what you are talking about, and I'll do the code and insert it in a Forum window.
                              Is there anything from this year's Pacific Life Open? The clip I saw is of him hitting two forehand's in a row from the backhand side of center. First one of the ground and the other seems like its out of the air from almost the BH corner sideline. He's wearing the blue version of the shirt he wore at the Australian open and blue or black short's with a stripe. I'm mentioning this because if you have any film from anyone that did high speed filming you may have it even if its not posted.

                              Comment


                              • #30
                                Look in the High Speed Archive. Those are the choices.

                                Comment

                                Who's Online

                                Collapse

                                There are currently 1563 users online. 0 members and 1563 guests.

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

                                Working...
                                X