Thrusts #1 and #4 are Accelerating (and mutually exclusive) Thrusts. Thrusts #2 and #3 are Non-Accelerating.
The question I answered required differentiation between the use of the Right Triceps in Thrust #1 (Muscle Power) and #2 (Extensor Action). And that essential difference is in Accelerating (the Left Arm moves) versus Non-Accelerating (the Left Arm is stretched but does not move). Hence the need for my broader classification of the four Thrusts into their respective categories.
If hitters can use an extensor action accelerating thrust...
Per 6-C-0 and my post above, Extensor Action is not an Accelerating Thrust. It is a Non-Accelerating Thrust. This is true for both Hitters and Swingers.
Per 6-C-0 and my post above, Extensor Action is not an Accelerating Thrust. It is a Non-Accelerating Thrust. This is true for both Hitters and Swingers.
Yoda,
It would be great to see you do a video short on extensor action.
It would be great to see you do a video short on extensor action.
Good idea, DG. In it I would use this winter-time drill to help students instantly understand the concept:
1. Without a Club and while wearing your long-sleeved shirt, sweater, or windbreaker, pull your Left Arm (only) out of its sleeve.
2. Grasp the end of the sleeve with your Right Hand and stretch it out. That is Extensor Action (Non-Accelerating Thrust #2 / 6-C-0-2)!
3. Now, while keeping your Head still and maintaining the stretched sleeve (Extensor Action), use your Right Arm and its bending Right Elbow to swing the Club to the Top (Right Shoulder High and On Plane). Pause and Feel the Right Triceps continuing its stretch of the lifeless (but now structured!) sleeve.
4. Finally, again while maintaining your Stationary Head and Extensor Action, execute your Downstroke, from the Top to the end of the Follow-Through (sleeve and Right Arm straight). If you use your Pivot and its Right Shoulder (Rotation inducing Body Momentum Transfer) to Accelerate the left sleeve through Impact, you are Swinging using Centrifugal Power (Accelerating Thrust #4 / 6-C-0-4). If you use your Right Arm to Accelerate the left sleeve through, you are Hitting using Muscle Power (Accelerating Thrust #1 / 6-C-0-1). In both cases, the sleeve remains stretched...by the Non-Accelerating Thrust of Extensor Action.
Good idea, DG. In it I would use this winter-time drill to help students instantly understand the concept:
1. Without a Club and while wearing your long-sleeved shirt, sweater, or windbreaker, pull your Left Arm (only) out of its sleeve.
2. Grasp the end of the sleeve with your Right Hand and stretch it out. That is Extensor Action (Non-Accelerating Thrust #2 / 6-C-0-2)!
3. Now, while keeping your Head still and maintaining the stretched sleeve (Extensor Action), use your Right Arm and its bending Right Elbow to swing the Club to the Top (Right Shoulder High and On Plane). Pause and Feel the Right Triceps continuing its stretch of the lifeless (but now structured!) sleeve.
4. Finally, again while maintaining your Stationary Head and Extensor Action, execute your Downstroke, from the Top to the end of the Follow-Through (sleeve and Right Arm straight). If you use your Pivot and its Right Shoulder (Rotation inducing Body Momentum Transfer) to Accelerate the left sleeve through Impact, you are Swinging using Centrifugal Power (Accelerating Thrust #4 / 6-C-0-4). If you use your Right Arm to Accelerate the left sleeve through, you are Hitting using Muscle Power (Accelerating Thrust #1 / 6-C-0-1). In both cases, the sleeve remains stretched...by the Non-Accelerating Thrust of Extensor Action.
so the left arm is just stretched like a sail on a sailboat and hangs on for the ride. correct?
and the extensor action does not power the backstroke, that would be the bending of right elbows job while the right forearm keeps the sail geometrically correct and constant? would that be a good way to view?
i've always kinda tried to stretch out with right forearm going up, you know kinda pushing it out out out, not really seeing this as the right elbows job. interesting.
so the left arm is just stretched like a sail on a sailboat and hangs on for the ride. correct?
and the extensor action does not power the backstroke, that would be the bending of right elbows job while the right forearm keeps the sail geometrically correct and constant? would that be a good way to view?
i've always kinda tried to stretch out with right forearm going up, you know kinda pushing it out out out, not really seeing this as the right elbows job. interesting.
That's the way it works, Powerdraw. You've got it now. Stay with it!
To all concerned: I've been doing a little research on the way muscles work a' la extensor action especially since I was wrong about YodasLuke's example of keeping a leaning man a constant distance from you with your bent right arm. In this example, the triceps muscle fibers would maintain the same length as tension develops. The force of contraction herein takes place within the fibers, but the fibers themselves do not move in relation to each other, so the overall muscle remains the same length. This type of force development by muscles is termed isometric.
If you were to let the man come closer to you but controlled his speed so he didn't crash into you, like my example of bringing a benchpressed barbell slowly back to your chest, then the triceps muscle fibers would be lengthening as they developed tension. This type of force development by a muscle is termed eccentric.
If you pushed the man away from you, your triceps muscle fibers would shorten or contract. This is the most familiar type of force development by a muscle, and it is termed concentric.
Muscles cannot develop a force concentrically, isometrically, or eccentrically at the same time. Muscles can only develop a force one way at a time, so if and when the triceps fibers shorten to move the left arm, extensor action (which supposedly does not move the left arm) can no longer be in effect. The triceps or any other muscle just isn't talented enough to develop dual or treble forces wherein the same fibers would have to independently and simultaneously contract, lengthen, and/or remain the same length.
Muscles cannot develop a force concentrically, isometrically, or eccentrically at the same time. Muscles can only develop a force one way at a time, so if and when the triceps fibers shorten to move the left arm, extensor action (which supposedly does not move the left arm) can no longer be in effect. The triceps or any other muscle just isn't talented enough to develop dual or treble forces wherein the same fibers would have to independently and simultaneously contract, lengthen, and/or remain the same length.
Coophitter
Thanks for your post, Coop. Have you tried my 'Armless Sleeve' drill posted earlier today (#86 in this thread), especially the Hitter's application? If so, I would appreciate your thoughts.
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
Linear Mode
