internal hip rotation

Discussion in 'Tennis Tips/Instruction' started by pushing_wins, Sep 27, 2012.

  1. pushing_wins

    pushing_wins Hall of Fame

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    the key to a good forehand, imho.

    has this been discussed yet?


    especially on the high forehand, most rec players are limited by their range of motion. internal hip stretches and excercises to increase ROM wiil add lots of power to the forehand.
     
    Last edited: Sep 27, 2012
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  2. LeeD

    LeeD Bionic Poster

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    use you legs to hit every shot...
     
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  3. pushing_wins

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    you will end up spinning around if you dont have a good range of motion in your hips
     
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  4. LeeD

    LeeD Bionic Poster

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    U can't employ your hips without using your legs.
     
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  5. Limpinhitter

    Limpinhitter Legend

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    I don't know what you mean by "internal" hip rotation. But, leading your UBR with hip rotation is definitely one of the keys to a modern forehand and a 2hb.

    True, but, it's not something you have to think about. When you rotate your hip, your legs act automatically. It's like turning and tilting your upper body on serve. Your legs do that for you, but, you don't have think about your legs. You think about turning and tilting your upper body.
     
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  6. Jonny S&V

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    Are you talking about both hips? Because the only hip that internally rotates on a modern, open-stance forehand is the left (for a righty). The right hip should externally rotate (for a righty).
     
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  7. Maui19

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    Swing the human racquet.
     
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  8. pushing_wins

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    right hip is more important. it rotates internally?
     
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  9. Chas Tennis

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    Muscles that internally rotate the hip.

    There are many muscles that internally rotate the hip.

    http://wiki.answers.com/Q/What_is_the_primary_muscle_for_hip_internal_rotation

    Some years ago my instructor had us raise the heel high to pivot on the ball of the foot. That internally rotates the hip.

    If I really want to push a heavy load of clothes along a closet bar I put my hand on the clothes and do this same pivot on the ball of the foot. It's a forceful way to push the clothes.
     
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  10. spacediver

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    huh?

    Haven't you got it backwards?

    (i don't think we're discussing the coiling motion here - we're talking about the uncoiling).
     
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  11. Chas Tennis

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    This demo video has a lot of useful information.

    The motion used in the exercise - pivot on the ball of the foot - was the motion an instructor of mine taught.

    See especially 7:40 of the tennis video for the hip rotation in a forehand.

    http://www.swing-speed.com/tennis.php

    Pushing_wins, is this the movement that you had in mind?
     
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  12. dominikk1985

    dominikk1985 Legend

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    we need to be more precise. which hip are we talking about?
     
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  13. dominikk1985

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    I believe that the foot pivot is more of a follow through action. the hips are not rotating on themselves, they are driven by the back leg. this principle is called ground reaction force in biomechanics. you are actually already pushing against the ground while the hips are still coiling backwards.

    If you are just pivoting you are not using the ground and spinning. and if you pull the hips/core around you are not using the ground either. you are only using ground reaction force if you drive the rear leg inward and forward.

    you can see the same very well with a baseball player

    [​IMG] [​IMG]

    the finish of the move is then more of an external rotation on top of the right femural head but first the rear leg is driving inward before the heel even leaves the ground (no spinning).
     
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  14. corners

    corners Legend

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    On a righty's forehand the right hip internally rotates during the coal or loading phase during the backswing. The right hip then externally rotates as the pelvis rotates toward the net, or opens, during the forward swing. The internal rotation of the hip loads the external rotators (pre-stretches the glutes, etc.) for expression of power during the swing.

    Tricky's drill of hitting your forehand while balancing on your right foot will highlight this motion for you. (And will teach you proper weight transfer, as you will "fall" onto your left foot as you swing balanced on your right foot. If you don't fall forward into your left foot you are not transferring your weight properly.)
     
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  15. Chas Tennis

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    That's a great video for illustrating internal hip rotation.

    I interpreted "internal hip rotation" in the OP using the anatomical definition as defined in the Manual of Structural Kinesiology.

    Internal hip rotation is axial rotation of the femur at the hip joint. It rotates the entire leg below the hip. If the foot were fully in contact with the ground and could not turn and the femur axially rotated then that rotation would be very limited because the knee and ankle have such a small ranges of motion for rotation. If the heel is raised so that the foot pivots around the ball of the foot ball then the whole leg is free to axially rotate. That is how I see the foot pivot.

    Is that your interpretation?
     
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  16. Limpinhitter

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    If that's what the OP means by internal hip rotation - femur rotation at the hip joint, then, I don't think that's directly relevant to hitting a forehand or a backhand. Rotation of the pelvis or pelvic girtle around the axis of the spine, is the relevant rotation, IMO. That's what I mean by hip rotation. That's what initiates upper body rotation and the kinetic chain and pulls the shoulders and ultimately pulls the arm and racquet through the swing.

    Femur rotation may be a necessary part of the process of rotating the pelvis. Maybe not, I don't think so, but, I don't know with certainty. But, that's not something a tennis player should focus on. A tennis player should focus on leading his upper body rotation with his right hip in order to initiate the kinetic chain.
     
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  17. dominikk1985

    dominikk1985 Legend

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    the kinematic chain doesn't start at the hip. it starts at the ground. the hips don't rotate by themselves, they are rotated by the ground reaction forces. if you just rotate the hips/spine it will be an empty rotation.

    but I agree that the internal rotation is not the driving force. it might start with internal rotation but then the hip will externally rotate on top of the femur-but due to the ground reaction force (closed chain) this will not cause the hip to rotate in the other direction but the hip to open.
     
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  18. pushing_wins

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    i see internal rotation as the ball is being thrown

    i m not talking about where the power comes from. i m only saying your need internal hip rotation flexibility to deliver the power.
     
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  19. pushing_wins

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  20. tricky

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    As corners pointed out, the one-foot drill teaches you what hip rotation actually is. Hip rotation facilitates balance, shifting or transfer of weight, etc. People associate hip rotation with the turning of the pelvis around the spine. This is actually not true.

    Hip rotation can also be done via visualization. Imagine a line drawn between the back of your head and the back fence. When you initiate your stroke or unit turn, that line should begin to increase. That part is tricky, because when most people initiate the unit turn, that line decreases. It's subtle, but it affects your backswing, timing, how you load your kinetic chain, etc.
     
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  21. pushing_wins

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    what would cause it to increase?
     
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  22. tricky

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    The distance between the knees changes and that causes your "center" to move onto one foot or the other. The visualization enables your brain to do this in a way that serves the stroke.

    Generally, when the knees move farther apart, the ground reaction force will be rotational/upward. When the knees move close together, the GRF will be linear/forward. However, this should be dictated by your natural stroke.
     
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  23. Jonny S&V

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    Oh, totally thought we were discussing coiling, my bad. Carry on (my wayward sons)...
     
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  24. albesca

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  25. boramiNYC

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    OP, yes internal hip rotation that occurs between femur and pelvis is very important in being able to use the core effectively. Too many rec players' muscles around pelvis (below and above) are ineffective (shortened and/or weak and stiff from non-use) very few can effectively use their core (hip and abs) in their strokes and for moving around the court. Anybody who improves control and effectiveness of this area would benefit hugely in their game. It's not only important in FH but in everything including simply walking and running. It's the key for great balance capability compared to average balance. I believe every single pro has this area very well controlled. It's like a requirement for a great athlete even tho they might not know in detail how things work in there.
     
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  26. boramiNYC

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    BTW, it's a very basic movement. Whenever the knee rotates there is internal hip rotation. And whenever the pelvis rotates relative to the knee there is the same rotation. Also to add ankle and foot strength and flexibility go hand in hand with hip-femur muscles strength and flexibility. It's how the body is coordinated.
     
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  27. Chas Tennis

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    Suggest that anyone replying check their use of kinesiology terms - search first on the internet and include a few links.

    There is a common tendency to look at the body part, for example, the knee, that moves or rotates and to call that motion 'knee rotation'. In kinesiology terminology the joint is identified and the motion associated with that joint. If you sit on a table with the leg hanging over the edge and rotate the foot that is 'knee rotation'.

    I have noticed that a small percent of the numerous Google illustrations are wrong or misleading. Best to get an anatomical definition.
     
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  28. boramiNYC

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    The knee joint in a very simple hinge joint with only one plane of movement. When I say knee is rotating, of course the the rotation is not at the knee joint. I thought no one would confuse that. I'm referring 'knee' just as a part of the leg. More precisely I'm referring to femur rotation but whenever femur rotates knee rotates and knee is easier to identify for general public. Guess I better be more precise next time.
     
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  29. bhupaes

    bhupaes Professional

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    Great thread, very informative. I had figured out the difference between hip rotation (at the femoral joint) and spinal rotation, but wasn't very sure if spinal rotation had any purpose other than orientation. Should one be actively avoiding spinal rotation in the interests of protecting the back, other than whatever happens naturally and effortlessly?
     
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  30. boramiNYC

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    There is nothing wrong with spinal rotation as long as the motion is within the limits. Using the rotation at ankle and hip can greatly add range and power to the body rotation. Without them it's possible to overwork the spinal rotation. Injured back is no fun and it affects the whole mobility so it's wise to be cautious but spine is wrapped in many many muscles and some are very strong so you don't need to underestimate its functionality, but strong and flexible legs will protect the spine from overworking or pushing out of the range.
     
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  31. boramiNYC

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    It's important to point out hip joint (pelvis-femur joint) is a ball and socket joint and designed to move in all directions. In our modern world where most of it's job is walking and running the muscles around it make the joint work like a hinge joint most of the time. That's the main reason why hip rotation muscles are very weak and undeveloped for most people.
     
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  32. pushing_wins

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    when i hit at 60%, i can hold my left side back

    when i start swinging at 100%, my posture starts to breakdown. i think the addition force requires more internal hip flexibility which i dont have.
     
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  33. pushing_wins

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    sorry, you lost me

    do u mean - do not shift your center of gravity?
     
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  34. r2473

    r2473 Legend

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  35. 5263

    5263 G.O.A.T.

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    Are you sure on this? If the hips are rotated my ground reaction forces,, what is
    causing the reaction? an action. The action starting at the hips, right?

    In martial arts we were taught the forces start at the hip and flow out in both
    directions...down to the ground and out to the action. Do you have a good
    source for your claim?
     
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  36. tricky

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    It (I consider this trunk rotation) helps define the overall size of the backswing/loop. If you want to add a ballistic element to this, there's two ways to do that.

    1) You can visualize a vertical stripe on the ball, and that your racquet face is making contact with that stripe.

    2) You can imagine your torso twisting around your waist.

    In both cases, what you want to look for is your loop to be "higher." Regardless of the size of the loop, the contact point should be about the same, though.
     
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  37. Cheetah

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    Are you sure about this? I was a brown belt in zen do kai which is karate and we were taught the forces start from the ground. When I swing my racquet I think about the ground as the start. Do you have a source for this? Maybe you are referring to chi lol.
     
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  38. spacediver

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    actually, i think i have it backwards. It's kinda counterintuitive, but I think I get how the hips actually externally rotate during the uncoiling.
     
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  39. spacediver

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    So let me get this straight. Is something like the following more or less accurate?

    For a righty forehand:

    At the start of the uncoiling, the femur develops an external rotation (clockwise if looking down from above), but the pelvic girdle develops a rotation in the opposite direction (counterclockwise from above).

    This all happens before the upper torso rotates, and when it does eventually rotate, it rotates counterclockwise from above.

    Is this accurate, and if so, how does this all interact with weight shift forward (tricky).
     
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  40. pushing_wins

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    do you have any advice for the lay person?
     
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  41. pushing_wins

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    http://www.youtube.com/watch?v=YyKcIzaM8Bk

    "People, you realize that the movement and what it stretches is the opposite? She is INTERNALLY rotating her hip (as shown by the femur rotating internally and foot swinging outward). That means this is an EXTERNAL hip STRETCH. You don't stretch something by contracting it. The Quads work to extend the knee, you stretch them by flexing the knee. You stretch internal hip rotators by rotating the hip externally. Therefore this internal hip rotation movement is an external hip rotator stretch. "

    "this is an internal stretch you idiot, your thinking bc the foot is going outside its external, but the femur is rotating inward, u idiot"
     
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  42. Chas Tennis

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    Video of Ben Hogan's Golf Swing with Internal Hip Rotation

    Short video by Ben Hogan discussing his golf swing and showing internal hip rotation. His swing videos are still frequently discussed on the golf forums.

    http://www.youtube.com/watch?v=QL_6M_xZvq0

    (Probably 1950s.)
     
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  43. dominikk1985

    dominikk1985 Legend

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    well in modern sports science the kinematic chain is defined as:

    the leg pushing against the ground which opens the hips, which turns the spine/shoulder.

    from former german davis cup coach and biomechanics expert richard schönborn:

    "the first movement is always against the ground"... (describes a dropping action)...

    "then follows the power impulse on the concentric work of the lower leg with an involvement of the quad and glutes, further up the trunk muscluature, the upper body, shoulder, upper and lower arm as far as the hand which is the last link of the kinematic chain".

    this is from a very good book called "advanced techniques for competitive tennis". it is from the early 00s or late 90s and describes the modern strokes pretty good.

    this is how most sports scientist in these days see the kinematic chain. there are different views in martial arts (more of a "middle out approach" and also among some scientists but most do believe in a ground up push off starting with the rear leg going through the hip, trunk, shoulders into the arm and racket.

    there are a lot of papers on this topic.
     
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  44. pushing_wins

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    whats that?
     
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  45. tricky

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    Instead of focusing ground-up, you instead focus on the mid-section (i.e. the core) towards the limbs (hands, feet. etc.)
     
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  46. pushing_wins

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    incredible external hip rotation on the left leg as well

    the legs are very quiet. most of the power come from the hips and core. as ben said in the video, the key is "what starts first" . its the hips that initiate, not the legs.

    maybe that the "middle out approch" in martial arts
     
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  47. pushing_wins

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    thats what i figured

    http://www.youtube.com/watch?v=Js6_WAS-Ay4

    notice the back leg kicking back. the only way for that to happen is to initiate with the hips.

    in other words, load the hips not the legs.
     
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  48. spacediver

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    anyone? I feel like I'm almost there, but not quite...
     
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  49. dominikk1985

    dominikk1985 Legend

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    you can do that if using only half of the kinetic chain is enough for you. the pelvis is actually part of the upper body anatomically. that means if you are just pulling your pelvis around you are not really using the lower body. a lot of players do that but this is not a high level kinematic chain.
     
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  50. dominikk1985

    dominikk1985 Legend

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    the kicking back happens after the legs gave their impulse to the hips. the concept of ground reaction force is one of the key concepts in biomechanics.
    If you say that the kinematic chain starts in the hips you are denying 50 years of sports science. tons of studies have been conducted on this topic

    for example here:
    https://ojs.ub.uni-konstanz.de/cpa/article/view/1932/1800
     
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