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Marshall's Straight Driveline??

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  • #16
    Because the hand/ball is moving in a circular motion, you are not applying force in the direction/path the ball travels. This is what you are missing. You are applying centripetal force.

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    • #17
      Love.

      “sun, moon and the stars” yes but we do it in conjunction.

      “fighting gravity”. No we fight most of it on the pendulum swing up to driveline height.

      Chris,

      Great video!
      We keep going back to the UCL distinct problem and the on the record stated injurious causes and fixes. This ligament is a hand fan like structure and radiates out in a non-linear fashion. Dr.Marshall states as the highest stress point in the delivery for the UCL is at the point where the ball has actually gone backwards fully with the elbow directly in front of the ball. Preceding cause is late forearm turnover and the High guard (goal post, grabbing) articulations. This position micro tears the UCL with every traditional pitch. Then it repairs it self in a short time over and over. Sparks had basically the same operation Gagne had, a shaving down of old calcium deposit and reshaping of the UCL. Many kids come back from UCL smaller tears without surgery; Sparks had 3 different tears from HS and College. He actually grinded his way through the Minor leagues with these huge calcium deposits.

      "(e.g. Randy Johnson and Nolan Ryan)" your kidding right? Ryan holds many records one of them is DL appearances.

      Is “PAS arm” redundant?
      Last edited by Dirtberry; 03-22-2008, 02:18 AM.
      Primum non nocere

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      • #18
        Originally posted by XV84 View Post
        Because the hand/ball is moving in a circular motion, you are not applying force in the direction/path the ball travels. This is what you are missing. You are applying centripetal force.
        So what? The hammer gets released and, once it does, becomes propelled on a straight line tangent to the arc. Why don't they just stand there with the hammer behind them, on line with the intended direction, pull the thing to release and let it go? Why do they spin several times before releasing? Why not spin only once? It's building up momentum over a longer distance/time.

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        • #19
          Dm I agree with you.

          The longer and later the more energy that builds up and can be used when the arm goes to throw.

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          • #20
            Originally posted by XV84 View Post
            Hammer throwers use rotation to create centrifugal force that causes the hammer to fly away from their body. They are not applying force in the (eventual) direction that the hammer travels.
            There must be a resultant force in the intended direction at release, or else it would not go in that direction. At the instant that force no longer holds the hammer in the circular path, it will move in a straight line, tangent to the arc. It's a timing issue. The circular path up until that point allows more time for force to applied and acceleration to happen, no?

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            • #21
              Originally posted by dm59 View Post
              There must be a resultant force in the intended direction at release, or else it would not go in that direction. At the instant that force no longer holds the hammer in the circular path, it will move in a straight line, tangent to the arc. It's a timing issue. The circular path up until that point allows more time for force to applied and acceleration to happen, no?
              The circular pathway you're describing with a hammer throw allows for momentum to be built up and kinetic energy is stored over time. Something similar happens with pitching and throwing, but in a more condensed timeframe. (And there are actually a series of arcs or loops that happen because each body segment gets added to the total.) The largest arc that ends up being scribed has as it centerpoint the spine, and the arm extends the length of the arc. The problem is that we're generating enough force that it becomes difficult, if not impossible, to overcome the force and the elbow reaches maximum extension or hyperextension. Here's proof that we know how to prevent elbow problems stemming from overextension. This pic illustrates 33° of separation between the axis of the forearm and longitudinal axis of the upper arm, at release. (And what you're seeing here was recorded on high speed imagery, delivering the ball at max intensity.)

              Separation.jpg

              In one sense an arc is inefficient because forces are being dissipated away from the desired line of travel. It's really about vectors in three planes of motion and not about the arc. The arcs are symptoms. Straight line drive is an interesting concept but it's never going to happen because we're dealing with a complex set of levers. Conceptually I think the way to deal with these issues is to think about the primary arc in a different way: consider an ellipse instead of something more circular. Try this: grab a CD or DVD (or anything circular) and set it on the table in front of you. Looking straight down, you see the outside edge as a circle. Now tip one side up about 45°. The circular edge now APPEARS to take on the shape of an ellipse. If we can drive the forearm along this elliptical pathway, the driveline indeed straightens out somewhat in all vectors, but it's still an arc with finite length. This is why a vertical forearm at the driveline's start becomes very important. If you start the forearm vertical and finish it almost vertical, we've removed lateral disturbances that are inefficient.
              www.rpmpitching.com

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              • #22
                I'm very confident that you've found a way to help the elbow in this situation. I'm just having conceptual difficulties with the arcing (or elliptical) path vs. a straight one (or approaching straight). It's the build-up of momentum idea. Golfers do it, hammer throwers, shot putters, etc. If they all shortened their path by attempting to straighten it, they would have less time for the build up of momentum, wouldn't they?

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                • #23
                  Dm59,

                  Making comparisons using an extra lever (hammer, bat, club) will never work to explain these different movements. You lumped Shot puter in with these also another distinct mechanic even though the shot put is casted as straight as you can get. New era Batting coaches have also mis-renamed (some thing already named) what they see as rotational that implies a circular path when it is also Elliptical.
                  Primum non nocere

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                  • #24
                    The point isn't whether it's a perfect, circular path and it's not that a shot putter's mechanics are different than a pitcher. The question is about the length of the path that momentum is built up over. A "not straight" one is longer. The shot putter builds up momentum as he spins. Again, why does a hammer thrower spin more than once? Doesn't a longer path offer more opportunity for force application?

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                    • #25
                      DM, you are still missing the point. Hammer throwers are not applying force in the direction of the throw. They are applying force to maintain the radius of the arc. This force is called centripetal force. They are "pulling" the hammer towards their body while rotating/spinning. They are not pulling sideways.

                      The path maybe longer, but the fact is it isn't straight. It isn't straight because the direction of the forces are different.

                      They spin to generate rotational/angular momentum/acceleration.

                      Marshall pitchers don't "build momentum" like traditional pitchers do. They simply "apply force" in a straight (as possible) line. Traditional pitchers "rotate" to create centrifugal forces that accelerate the ball to fly away from the body. This is what causes, as Coach45 mentioned, extension of the elbow. Marshall pitchers "push" the ball.
                      Last edited by XV84; 03-22-2008, 06:49 PM.

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                      • #26
                        Originally posted by dm59 View Post
                        Doesn't a longer path offer more opportunity for force application?
                        Possibly, but not necessarily. If the force applied along a curved pathway (longer distance than a straight line) also means that it takes longer to cover the distance then answer is no. If it covers a longer distance in the same time frame the answer is yes, because velocity also has a time component. The mathematical relationship between the two is not linear, it's a function of π (pi). This becomes a circular argument (no pun intended) unless you can measure the time/distance factors involved, and that means using something like 3-D motion capture analysis (which we have done).

                        The real issue you're hinting at is this: can centrifugal force be harnessed in a productive way that doesn't damage the arm? I think the answer is yes. The hips and shoulders have width and as such generate rotational force when fired forward. As such there MUST be lateral displacement of the ball as the hips and torso turn. (This is one reason why a straight driveline Marshall postulates is flawed. Interestingly enough when we looked at his technique on the motion sensor-based system the glove knee, center of mass, and throwing shoulder end up almost in vertical alignment...and that's a really bad idea on a number of accounts. And this vertical alignment happens as his students TRY to adopt a straight driveline.) The question becomes how to practically and productively minimize the lateral displacement of the ball, and the answer is an elliptical pathway vs a circular one when viewed from overhead. It works, in conjunction with inward rotation of the upper arm and forearm pronation timed to coincide with release, preserves velocity. By combining these elements we've ended up with a repeatable, teachable skill.
                        www.rpmpitching.com

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                        • #27
                          Dm59

                          The problem here is mixing apples and oranges if you are trying correlate a hammer throw with it’s built up momentum opposed to an object starting from 0 velocity. When “Over early rotation”(traditional) pitching initial forward force application starts it heads toward the opposite facing bag, when a straight initial forward force application is started it is already gaining forward momentum, now you have already lost forward velocity With early rotation, now add in the loss that as you attain by fighting to get it back to straight. Imagine taking it to an extreme by just leaving your arm straighter to get as much arc length that you can. Now add in the loss of finishing short because of arc(elbow down across the chest).
                          I see straighter as more forward length quicker.
                          Marshall knows this tenet of his will probably never get met but getting closer to it is optimum.

                          XV84,

                          “Marshall pitchers "push" the ball.” Not true they have just as much whip and snap as traditional, they drive the ball then pronate snap it. They just do it with less deleterious ligament involvement.

                          Coach45,

                          Your forcing me to dump my well working Pentium III.
                          That’s not related to this thread!
                          Primum non nocere

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                          • #28
                            Originally posted by Dirtberry View Post
                            Coach45,

                            Your forcing me to dump my well working Pentium III.
                            That’s not related to this thread!
                            ????????????????????????? Get a Mac. Get a life.
                            www.rpmpitching.com

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                            • #29
                              does it come with a web browser?
                              Primum non nocere

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                              • #30
                                Yes, it comes with a mac native browser: Safari. But you'll do better to download Mozilla Firefox (free) for whatever platform you're working on.
                                www.rpmpitching.com

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