well, i hit some balls last night with my sail analogy, inert left arm, a little sleeve tuck down then right elbow bends back and extends through. it went well but sure feels like there is alot of right arm thrust when you concentrate on this, any thoughts?
It's an interesting point ,I recently measured the force of (my) extensor action using a spring scale it was between 12&15lbs.This seems like i'm overdoing it because it tends to make me tense up a little.....but who knows-maybe that is the point and it is just MY feel.Hopefully there is a comment out there from a Yoda'Yodasluke, Manzella or any of you experts on quantifying extensor action.Yoda and Ted used a bungee cord to demo at the swamp...but these cords vary in strength.
It is very difficult to discuss this magic right forearm. In my tether ball example and swingset example the thrust applied to both objects may be a little more than 90 degrees to their respective tether lines and then the objects separate from pressure points at 90 degrees. So initial thrust at more than 90
degrees can act as an initial stretching force on the tethers, but by separation this force is no longer acting on the respective tethers.
In a golf swing where you exert a little triceps thrust at address to stretch the left arm tether and then feel that this thrust is still in effect through the backswing and downswing is quite confusing to me because I feel it too, but if there was a true magic right arm thrust down the line of the left arm tether then the left wrist would have no cock at address and wouldn't cock at all during the backswing. Also when the right elbow bends on the backswing and the triceps fibers lengthen, an eccentric force is developed that can apply thrust to slow down an object, but it can't stretch or move the object concentrically, and it can't keep the object the same distance away isometrically. What we are feeling on the backswing is the triceps developing a force that prevents the elbow from bending too quickly and/or too much.
On the downswing we feel the concentric contraction of triceps fibers that straighten the elbow in hitting, but the initial thrust is not down the line of the left arm but quite close to or at 90 degrees against the line of the cocked left hand. True extensor action down the line of the left arm can only occur when the left wrist is uncocked. I'm going to stop now because I'm getting quite confused and need help, but I really think that extensor action as described by kelley is an isometric force wherein triceps fibers would remain the same length during force production. If the elbow bends or straightens, the fibers are not remaining the same length and different forces occur.
Extensor Action -- What Is Being Pulled Into A Straight Line?
Originally Posted by coophitter
...if there was a true magic right arm thrust down the line of the left arm tether then the left wrist would have no cock at address and wouldn't cock at all during the backswing.
...What we are feeling on the backswing is the triceps developing a force that prevents the elbow from bending too quickly and/or too much.
...True extensor action down the line of the left arm can only occur when the left wrist is uncocked.
Using Pressure Point #3 (Right Hand Forefinger) to stretch the Left Arm and simultaneously pull the Clubshaft into line with it does indeed inhibit the Left Wrist Cock. However, using Pressure Point #1 (the heel of the Right Hand against the Left Hand thumb) to stretch the Left Arm only does not.
As you have noted, the Right Triceps Extensor Action -- by definition the 'steady effort to straighten the bent Right Arm' (6-B-1-D) -- does indeed prevent the elbow from "bending too quickly and/or too much."
Here are some silly ways (working with my son- forgive me) to think about the extension action and the flying wedges:
At address the hands begin to establish the flying wedges but they are loose. The small tug of the right hand GLUES or SNAPS the wedges tight. This tug is the start of the running dog.
The right hand is that dog- running free as it takes the club back but the left arm is a leash that stags the still running right hand dog at the top of the back swing .... Checkrein Action
Dog is still running (in place) on the down stroke in a linear direction away from (along the shape of) the forearm- not in the direction of the path of the hands. If the dog stops running the glue comes apart. That bungee cord shrinks. The leash gets limp. No sitting mutts.
The other end of the dog’s leash is the left shoulder. That post is now moving the dog and leash. The dog (right hand) for swingers does not move the leash along the path- it is still running in a linear line (not to be confused with the right elbow straighten and driving- like a big wind blowing the dog sideways). The left shoulder- the leash post- moved to the right and now is pulling back to the left back to its center.
Hello Yoda: Yes I have tried and presented an armless sleeve like drill to countless students ever since I saw Greg McHatton present an armless left sweater sleeve drill at a PGA Teaching Summit many years ago. Tomasello also showed me the same rope and short club drill that he used in one of his Australian videos to expalin extensor action to me. I've also seen Ben Doyle and Mike Hebron explain it. Hebron seemed to be reading a Doyle script when he explained extensor action. I don't think Doyle has ever used anyone else's words except perhaps in recalling or interpreting Homer Kelley's words.
I was initially thrilled and enchanted by these demonstrations and explanations of extensor action, yet now I've become brave enough to be flat out wrong in my assessment that Kelley and all the aforementioned luminaries have dropped the ball when they claim that constant triceps force production is always trying to stretch yet not move an inert left arm. I can only explain my argument with two hopefully vivid example of the way anything close to GM defined "extensor action" might actually exist in golf strokes. Both examples are similar in concept, yet there is one big difference in the two. The first example initially applies a GM defined muscular extensor action to its advantage while the second doesn't need to apply muscular extensor action and doesn't.
Example #1. A person preparing to bash and then bashing a tetherball in the most efficient and effective way: A right handed performer holds the tetherball in his left hand as he stretches or tautens the tether as far as he can 180 degrees away from the pole. He then twists his spine, raises and cocks both his right arm and clenched right fist and commences to deliver a full bodied right arm pinky blade of the fist leading bash directly to the back center of the ball in a 90 degree or perpendicular direction in relation to the pole and the tautened tether. The millisecond that the ball is contacted and begins to move, the human force that tautened the line 180 degrees away from the pole no longer acts on the tether, but is replaced by the 90 degree force which now stretches the tether as the linear force that bashed the ball resists the inward centripetal pull on the tether caused by its attachment to a stationary vertical pole. Both forces cause the whole unit to fly in a circular motion on a relatively horizontal plane until gravity and friction overpowers these two forces. There was GM extensor action only at the address or starting condition of the tether and ball.
#2. A man pushing a child on a swing: He uses a full bodied double arm shove against the back of the child or the seat in a 90 degree direction compared to the two chains that attach the child to the swing's top bar. The whole system is diverted into a circular motion on a vertical plane. The linear force provided by the man against the back of the child resists the centrpetal pull and keeps the chains stretched to their maximum length until gravity and friction slow and stop the forward swing. The swing then returns to the man on the same vertical plane with chains stretched via the linear force of gravity pulling the system straight down combined with the centripetal pull of the swing into its circular motion on a vertical plane. Any GM defined extensor action in this scenario could only be provided by gravity and the equal opposite outward force that automatically occurs in response to the inward pull of centripetal force. No muscular force is ever applied along the lines of the chains to keep them taut.
What does all this mean relative to golf strokes. I'm not sure, but I believe that all of the direct muscular linear forces applied to most effectively pull or push on the left arm are applied perpendicularly or 90 degrees to its line and not parallell or 180 degrees to its line. Perhaps at address a 180 degree muscular force can be applied to the left arm like in the tetherball case but it isn't necessary and therefore not always applied. I could be dead wrong about all of this or we are all right and just arguing semantics. Linear force is moving the system during acceleration phases and linear force is keeping the system stretched during acceleration phases in good tetherball, swingset, or golf swings. What type of force moves the swing or maintains the swing's stretch during its movement will perhaps always be debatable. Does muscular or resultant force move and/or keep the system stretched?; that is the question and whether tis nobler ... All I'm sure of is that all human motions of bones about axes are angular and all of these angular motions can be linked to initial linear muscular forces. Again I've written too much when I said I wouldn't. Thanks for the reply and I hope I've confused rather than clarified, otherwise there would be little to ponder. Coophitter
Coop,
Love the thoughts but had a couple of questions. First of all, I have never actually played tetherball but I think I saw it on ESPN Ocho about 2am one night.
Seems to me that in example one the tetherball post represents the left shoulder, the tetherball cord represents the primary lever assembly and the ball represents the hands. To me, the question is, what part of the tetherball motion is analogous to a golf stroke. Taking the thetherball from a fully limp position beside the post to the 'top' requires pressure against the primary lever assembly applied against the ball (hands) lets call that pressure point #1 action and it moves the assembly 180 degrees away from the 'target'. The right hand 'hit' is applied while the cord is still taught and the cord remains taught until the right arm is completely straight and the ball is gone. Seems to me that extensor action was evident all the way to a both arms straight condition after the right hand 'hit', ie the Follow-through. Yes, Mr K says that extensor action is evident until the Finish in a golf swing, but in a golf swing we don't let go of the primary lever assembly with our right hand after Finish, so the analogy with the tetherball is not perfect.
As for the swing(#2) seems to me that the actual weight of the child in the swing represents the constant downward pressure of extensor action keeping the chains taught. (Ever pull back a swing with no weight on it? What happens?) Without any weight on the chains they would become limp and unstable both in the backswing (pulling back the swing) and the forward push of the swing. This extensor pressure remains constant all the way through the both arms straight condition when the swing is released. In this case the pressure never disipates, but for practical purposes the 'stroke' is essentialy over once the arms are fully extended.
It seems to me that extensor action is evident throughout the entire stroke in both your examples. It is clearly beneficial (I won't dare to say 'necessary') for providing the structure for an on-plane motion. But then again, I just got out of bed and haven't had my coffee yet, so I may be completely wrong.
Hey Triad, Thanks for the response, my argument is that the extensor action in a swingset example is not muscular and neither is it in the tetherball example. The extensor action in both cases is a resultant force and not a direct muscular force. I think extensor action exists in golfstrokes, but it is not developed and maintained by a constant isometric triceps muscle force. I didn't think about the weight of the child, very good observation!
Actually, Triad, I surmized that the extensor action in the tetherball example was muscular at the start but then a resultant force thereafter.
Coophitter, I understand your point and agree with you. My assertion however was that once the ball has been struck by the right hand and the right arm is fully extended you have reached a Follow-through condition of both arms straight. (I believe I inadvertantly said 'finish condition' in my previous post.
After the Follow-through is where the analogy with a golf stroke ends. The resultant swing of the rope is just a reaction to that 'golf-swing' (hit, actualy). Even if we were to assume that the continued swinging of the rope around the pole is part of the golfswing and driven by centrifigal force or momentum transfer rather than muscular driven extensor action we still should be able to agree that extensor action is evident all the way to the both arms straight condition since the left hand is holding the rope taught while the right arm drives through the tetherball. Not sure if I am being very clear. Am I making any sense here?
should be able to agree that extensor action is evident all the way to the both arms straight condition since the left hand is holding the rope taught while the right arm drives through the tetherball. Not sure if I am being very clear. Am I making any sense here?
this is where i'm at, but doesnt that sound like a hitters procedure? wheres the pivot for the swinger in all this? is the pivot driving the ropey left arm or is the right arm?
Linear Mode
