Hand-Eye Coordination

Discussion in 'Tennis Tips/Instruction' started by Blee1613, Sep 21, 2011.

  1. Blee1613

    Blee1613 Semi-Pro

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    I just shank a lot and it's just awful... I hate it when I do it, and throws my game off. I'm keeping my head still at the moment of impact. So are there any other drills and/or tips to improve this? Also, I had to switch from contacts back to glasses because of my dry eyes, could this be a factor in my lowered accuracy?
     
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  2. junbumkim

    junbumkim Professional

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    Did you shank a lot with contacts?
    There could be a lot of reasons - trying to hit too hard, or not picking up the ball quickly enough with your eyes, etc etc.

    My eyes are pretty dry and sensitivie to light. I went down in my prescription and switched from Toric to non-toric even though I have strong stigmatism. Since then, contact lens feel a lot more comfortable. I still see well enough with these contacts..
     
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  3. mightyrick

    mightyrick Hall of Fame

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    Do some drop-hitting. Stand in your hitting stance. Drop a ball, swing forward, and hit the ball. Do you still shank? Drop a ball again. Swing forward faster. Do you shank? Most of the time, if you are shanking, it is because you aren't tracking the ball all the way to contact. Keep your eye on it. You might think you are, but you probably aren't. Really focus on the ball. Don't just focus on the vicinity of the ball. Focus ON it. Inner Tennis even recommends trying to look at the seams as they spin if you can't focus on the ball itself.

    Even Federer and the pros shank. When does that happen? Usually it is because the ball takes an unpredictable bounce and they lose track of the ball -- or the ball surprises them.
     
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  4. Blee1613

    Blee1613 Semi-Pro

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    I didn't shank this much with my contacts in. Maybe its just that my glasses are flying all over the place, especially with sweat on my face.

    And I'll try the dropfeed thing. But are there any specific drills I might do?
     
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  5. mikeler

    mikeler G.O.A.T.

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    I shank quite a bit, more on my forehand than backhand. Try using your off arm to track the ball on your forehand, that seems to help some.
     
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  6. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    [​IMG][​IMG]

    The eyeglasses are a (temporary) problem due to refraction of light passing thru the lenses. This is the same phenomenon that makes a straw or a stick that is partially submerged in water appear to be bent or offset. As light passes from the air to your lens it is bent. As light passes from the lens back to the air (between your lens and your eye) it bends again.

    Because the lenses in your glasses are much thicker than your contact lenses (and are away from your eye), the refraction effect will be much greater. The refraction index for glass is probably different than the index for plastic. The thin lenses of your contacts probably cause very little or almost no distortion or displacement of light.
    [​IMG]
    Over time, as you play more tennis with your eyeglasses, your brain will start to correct for the refraction offsets and your shanking problem should subside considerably. The same thing happened to me when I started using sunglasses when playing tennis. I would mishit the ball quite a bit. Eventually, my brain would correct and I would start to hit cleaner shots. At first, when I removed the sunglasses after playing for a while, I would mishit a few balls again until my brain re-corrected for the lack of lenses.

    Since I've been playing with sunglasses for quite a while now, my brain corrects immediately when I put them on or take them off -- it's (a lot like) a type of muscle memory.
    .
     
    Last edited: Sep 22, 2011
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  7. larry10s

    larry10s Hall of Fame

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    SystemicAnomaly
    you and charliefederer really are so analytical and scientific
    that i really learn alot from you guys:)
     
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  8. thug the bunny

    thug the bunny Professional

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    Same thing, even more so in golf. I can't hit a ball to save my life with sunglasses on. I'm trying to get my boy to stop playing with shades on but he's all about the coolness factor.
     
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  9. LeeD

    LeeD Bionic Poster

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    Some guys strap their glasses on, so it doesn't move whatsover. Some wear hats that help locate the glasses straps solidly.
    Glasses need to be big enough to give almost full vision, or as much as you need.
    I have granny glasses which greatly improve my vision, to pinpoint reading the label. Unfortunately, the wire rims are always in the way, and sunlight causes refractions and shadows, my sweat causes slippage and poor vision, and every overhead is out of my line of vision.
    So I play half blind without the -1.25 glasses.
     
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  10. junbumkim

    junbumkim Professional

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    I think eyeglasses come with special coating that compensates for refraction. .
     
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  11. dasob85

    dasob85 New User

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    also keeps the sweat from dripping onto the glasses as well. bandanas also work very well when you dont need a cap and wedges the frame legs into your ears so they dont move.
     
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  12. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    Have not heard of any such special coatings. However, prescription glasses are made of various different materials that have different refraction properties. The shape and thickness of the lenses also have an effect. Prescription glasses are usually made to correct for refraction errors of the eyes. They are supposed to bend light so that it falls on the retina correctly.

    The lenses will bend the light in a manner to help the eye to focus better. However, I am not sure if they will necessarily correct the offset problem that I mentioned in my previous post. In the case of my sunglasses and Blee1613's eyeglasses, this appears to be the case.

    I would suggest that the OP pay a visit to his/her optometrist to see if this effect can be minimized with different lenses. The other option would be to continue to use the current glasses until the brain learns to correct for the offset.
     
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  13. thug the bunny

    thug the bunny Professional

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    Refraction is caused by light passing through mediums of differing density, so there's no way a coating will correct for refraction. As SA points out, that is the function of perscription glasses - to refract light in such a way as to correct for the eye's lens incorrect refraction.

    BTW, the perceived offset of an object will be zero if the line of sight is perpendicular to the lens and will increase as the angle of the line of sight to the lens becomes more acute.
     
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  14. Blee1613

    Blee1613 Semi-Pro

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    I have no idea what that means. Haha please "dumb it down" so to speak.
     
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  15. thug the bunny

    thug the bunny Professional

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    If you look at SA's diagram, you can adjust the angle of the incedent ray to 90 deg (perpendicular) to the refracting medium, and then there would be no shift in the location of the target (in other words, looking through your glasses straight at the ball). However, if the target is to one side such that the line of sight hits your lens at an angle (other than 90), refraction will occur.
     
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