stretch shortening cycle

Discussion in 'Tennis Tips/Instruction' started by looseswing, Jan 12, 2007.

  1. looseswing

    looseswing Professional

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    What is it? Should 4.0s like me try to implement it? How to do it and get a feel for it?
     
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  2. ubel

    ubel Professional

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  3. looseswing

    looseswing Professional

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    Actually, from what little I've read about it, some coaches seem to be experimenting with it, so perhaps its not all bad.
     
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  4. Ross K

    Ross K Legend

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    Is it a clothes washing machine setting?
     
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  5. Ross K

    Ross K Legend

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    Actually... seriously... can somebody please enlighten us?
     
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  6. Solat

    Solat Professional

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    from wiki

    As a muscle lengthens, it contracts and produces elastic energy. The force applied to the muscle increases. The muscle then contracts concentrically. The muscle shortens and the energy that has been stored dramatically increases the force of the contraction.

    During the eccentric contraction, the muscle stores elastic energy. Muscular tension increases. The elastic energy that has been stored is available for powerful, dynamic movements. By stretching the muscle before it contracts, the muscle contracts with greater force. A consistent plyometric training program will increase the efficiency of the stretch-shortening cycle.

    in everyday terms

    you have an elastic band, you pull on it and it stretches becomes taught and stores elastic energy, when you release that tension the band flies off in the opposite direction.

    Now relate this to muscles, you have paired muscles around the body one that flexes and one that extends (to put it very basically). now if you flex a muscle it stretches the opposing muscle (creating tension) and when you release the flex (and commence the extension) you release the energy(back to the rubber band theory). The reverse also applies, ie extension of a muscle allows greater flexion.

    Now the idea behind the stretch shortening cylce is that elastic(dynamic) energy is only store for a very brief amount of time (and decreases exponentially) so you must use it whilst the muscle is still elastically stretching not staticly stretched. Lets use jumping as an example, if you crouch and then wait (static) then jump as high as you can you will reach a certain height - lets call it "A". Now if you crouch and jump in one flowing motion you should (if the theory is correct) jump higher then "A" so lets call this "B". Now the theory actually can be furthered to say that the more dynamic the stretch the better the elastic energy. So now if instead of just standing in one place we now step then crouch then jump (more dynamic therefore more elasticity) we should go even higher then "B"

    So how does this relate to tennis? The easiest example is the wrist on the multi-segmented forehand, now what you want to do is keep wrist loose, and then swing from the shoulder, this will create "lag" of the arm and especially the racquet. Now the racquet lag creates a dynamic stretch of the wrist, it is not a controlled extension by the player (some players however do control this wrist extension "cocking the wrist" ie Sharapova) since the arm is now accelerating toward the ball and the racquet has no momentum it lags until the wrist is pulled by the arm which then causes the wrist to flex bringing the racquet thru with a greater speed then those who have the wrist pre-extended

    to answer the original question: It will give more spin and power but it is also harder to execute thus creating more errors. Should you implement it ? if you want a big game then yes, if you need more spin then yes if you want consistancy maybe not.
     
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  7. baros

    baros Semi-Pro

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    go to virtualtennisacademy.c o m
     
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  8. looseswing

    looseswing Professional

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    Thanks for the excellent post Solat. So basically we should not do anything to implement it except stay loose?

    To baros, I don't have the kind of money needed to pay for VTA.
     
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  9. Solat

    Solat Professional

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    so long as you use your torso to initiate rotation and swing from your shoulder because if you swing from the hand then you will initiate the wrist movement
     
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  10. ubel

    ubel Professional

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    Thanks a lot for explaining that, makes a lot more sense. So it's basically muscling the ball with stored, elastic energy?

    And if it is, can it be applied in the same way if one were to look at the components of a serve (sorry if this isn't completely right, hopefully JCo or someone else more knowledgeable in the aspects of a serve will step in to correct any error):
    • Using example B from your original post, we crouch, then drive our bodies up
    • This drive causes an SSC (stretch-shortening cycle) in our hitting shoulder which we pull upward by rotating our shoulders (throwing arm comes down, racquet arm comes up)
    • This rotation causes an SSC in our tricep which we bring upward by contracting it and extending it at the elbow (aka getting full extension)
    • This contraction causes an SSC in our wrist which acts as a whip by extending upward and aligning with our forearm (contact point), which rotates and allows us to follow through on our serve
    Sound about right or have I flubbed up the idea of the SSC?
     
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  11. JCo872

    JCo872 Professional

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    Good stuff guys. I'll add one piece. You really need to finish with the windshield wiper finish to do this. And second, if you just relax your forearm and hand a bit as you come into the ball, the racket will catch up with the rest of the hitting arm. On contact, and through the windshield wiper finish, the hand, arm, and shoulder all work together.

    It is just a small game of "catch up" that can add momentum.
     
    Last edited: Jan 14, 2007
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  12. JCo872

    JCo872 Professional

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  13. Solat

    Solat Professional

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    #13
  14. ubel

    ubel Professional

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    Do you think that the catch-up is forced, even in the slightest bit, in order to increase power, or do you think that it's the natural spring of the wrist? I believe it is forced.
     
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  15. JCo872

    JCo872 Professional

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    Ubel,

    I can only speak from my own experience. What I do is rotate my shoulders into the ball which gets the butt of the racket to the lead the stroke with my hand flexed back and down. As I get close to the ball I just slightly relax my hand and forearm and the racket catches up a bit. Then I windshield wipe through, up, and then over to my opposite side. My wrist however, stays back through contact as I am windshield wiping. And I feel that the winshield wipe comes from my hand, forearm, and shoulder all coming through and over in a rainbow like finisih.

    Jeff
     
    Last edited: Jan 15, 2007
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  16. Solat

    Solat Professional

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    you paint a pretty picture Jeff :D
     
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  17. Ross K

    Ross K Legend

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    Guys, this particular aspect has always been slightly unclear for me... is the following statement correct?

    After loading the racquet over shoulder, the forward swing is initiated by THE BUTT CUP PULLING INTO AND LINING UP THE BALL... from which all else on the shot follows...

    Is that how you'd describe it?
     
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  18. JCo872

    JCo872 Professional

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    Well the shot is initiated by the uncoiling of the shoulders and hips, which pulls the butt cap of the racket forward.

    You can see an extreme example of this here:
    http://www.hi-techtennis.com/forehand/videos/djokovic_demo.php
     
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  19. Solat

    Solat Professional

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    Jeff,

    great example, there is the perfect angle of the stroke where you can see his forearm in front but his racquet is lagging beautifully still behind.

    Great work
     
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