The Release w/Brian Manzella & Michael Jacobs

[GeoffDickson]

The red arrow is a vector representing the direction and amplitude of the total force exerted on the club end.
.

Thanks Mandrin...an image like that is worth a 1000 words. One thing I don't understand...why are the first 4 or 5 arrows 'pointing up'..I would have thought they would be in the direction of the butt of the club (like the other red arrows)??? I suspect it's to do with Brian's 'jacknifing' analogy.

 

[birly-shirly]

I may be wrong but, looking at the pictures, it seems to me that the release is "active". Right or wrong?

Looking just at Miura's diagrams, or also Mandrin's?

Does a torque about the coupling point form a component of the red vectors shown on Mandrin's graphic?

 

[dbl]

Mandrin's diagram offers some great information. Notice the force direction at the very start of the backswing includes some 'away from target". I also see for about half the stroke the golfer could feel like he is pulling on the shaft downwards toward the earth in the direction of the shaft BUT once at the last parallel the force shifts and becomes aligned with the shaft.

 

[Kevin Shields]

Mandrin, thank you for the diagram. Its priceless.

 

[Michael Jacobs]

Mandrin's diagram offers some great information. Notice the force direction at the very start of the backswing includes some 'away from target". I also see for about half the stroke the golfer could feel like he is pulling on the shaft downwards toward the earth in the direction of the shaft BUT once at the last parallel the force shifts and becomes aligned with the shaft.

As stated many times in the thread, looking down at the swing action from a birds eye "right angle" view is extremely important

 

[footwedge]

Mandrin,

Why are there two vectors originating from the fourth from last point?

Drew

Isn't it just the continuation of the red arrow from the 5th last point.

 

[mandrin]

What's the centre in your graphic mandrin?

wulsy,

The figure is derived using a double pendulum math model. The centre can be taken as the mid point of the shoulders. The dashed line as representing the arms.

 

[mandrin]

Great Pic Mandrin... One quick question: FORCE FIRST TANGENTIAL THEN PERPENDICULAR TO THE ARC -- What word would you use to describe Perpendicular to the arc????

Michael,

A quick response for a quick question.

Perpendicular.

However it might just be that you want to know if there is a difference between perpendicular, normal and perhaps orthogonal. All refer basically to 90 degrees but are used somewhat more specifically depending on the context such as orthogonal dimensions, a vector normal to a surface or perpendicular lines. In our 2D case I really have no preference using either normal or perpendicular.

normal -
4. Mathematics
a. Being at right angles; perpendicular.

 

[Robbohank]

Brian - your explanation 'in 60 words or less' made this all really click for me. Illustration by Mandarin is great too.

Prior to this, I would have doubted I've been dragging that handle, but I sure ain't as "pure" as that illustration indicates.

Bertram,

Good point. There's handle-dragging and then there's handle-dragging. A week after my lesson with Brian I think I'm getting a better "handle" on it (sorry, couldn't resist) and I'm sure it's a function of where you're coming from. As different a feeling it is for me I can tell that I'm getting more comfortable with the concept of having more of a normal force at impact.

BUT - it is a VERY different feel and one that my body simply doesn't totally accept yet, but it's getting there in large part b/c of the results.

 

[mandrin]

Thanks Mandrin...an image like that is worth a 1000 words. One thing I don't understand...why are the first 4 or 5 arrows 'pointing up'..I would have thought they would be in the direction of the butt of the club (like the other red arrows)??? I suspect it's to do with Brian's 'jacknifing' analogy.

GeoffDickson,

I can quickly give you a simple intuitive explanation.

For a very short while, from the top, the club and arms form one solid body. For this small time interval one can approximately replace the club and arm in the model by the clubhead mass connected with an arm directly to the inner centre, as illustrated in the figure by dashed green line.

Since the inertial forces of motion can still be neglected one only has an external force, caused by the torque at the centre, acting on the clubhead mass, neglecting gravity. The direction of this force is in the direction of initial motion as shown by the green dashed arrows.

This simplified model is only valid for a short interval as very soon the inertial forces start playing a dominant role and moreover the club and arm are becoming 'separate' bodies, connected by a hinge.

 

[mandrin]

Looking just at Miura's diagrams, or also Mandrin's?

Does a torque about the coupling point form a component of the red vectors shown on Mandrin's graphic?

birly-shirly,

Yes. The hands/wrist torque is an integral part of the forces acting on the club and forms a component of the red vector. In this particular case the wrist torque is only active briefly from the top to prevent back knifing, i.e., making the arms and club behave effectively like one solid body. Have a look at the thread, Release action, Figs 33a and 33b.

 

[GeoffDickson]

Mandrin...given the time span is so short, I would presume that a conscious effort to apply force upwards is inappropriate / misguided?

 

[cmartingolf]

I believe that Ernie Els also has a similar move as DT at the beginning of the DS.

How does all of this info line up with the "wide (BS)" to "narrow (DS) thoughts? Should we all strive for a wider hand path in the DS with no thought as to actually getting the right elbow in close or to touch the right side early in the DS?

Is the feeling more of a smooth continual acceleration from the beginning of the DS instead of a quick burst of acceleration at the bottom (snap release?)?

Have not had a chance to watch the videos from MJ & BM yet as my computer speakers are on the fritz. Hope to solve that today.

Could it be that many "flipping" issues are caused by trying to hold much angle too long and then have to flip in order to try to square the clubface?

Thanks - Bruce

I finally feel redemption for being called a flipper. I always knew every decent player "flicked" it and had the left wrist clearly bent immediately after impact. I guess I couldve prepared my flick a little better however, when I was young.

Sorry for the late post. Just catching up on all this, but this is how I felt too!!! Knudson was a flipper

 

[dschultz6072]

So in accordance with how the new thinking about the golf swing is going here, how would you explain to someone get the normal force at impact but not present the club to the ball with a high handle? It seems to me everything about "lining it up" seems upward, including the handle.

 

[birly-shirly]

birly-shirly,

Yes. The hands/wrist torque is an integral part of the forces acting on the club and forms a component of the red vector. In this particular case the wrist torque is only active briefly from the top to prevent back knifing, i.e., making the arms and club behave effectively like one solid body. Have a look at the thread, Release action, Figs 33a and 33b.

Thanks Mandrin

I think I understand what you're saying - and that it's consistent (at least in the general sense that I understand it) with how Jorgensen analysed the swing.

In the second half of the downswing, you show zero wrist torque (your fig33b) and what Brian and Michael are calling the "line-up" of the club is a result of the combination of the centripetal force shown as red vectors in your diagram above, and the centre of mass of the club not being directly in line with that vector. Is that your view of things?

If so, that seems to contradict what I think Michael and Brian are saying about an active torque about the coupling point - and the idea that every release in a full swing is "active". If I've understood BM/MJ correctly - they stress a conscious, deliberate attempt to rotate the club about the coupling point, whereas in your analysis the rotation about the coupling point is just the reaction to force applied "along the shaft".

Apologies if I have misrepresented anyone's thoughts - but isn't there a contradiction here?

 

[wulsy]

My thoughts were very similar to your last post, birly.

Bear in mind though that this model is 2-D and in addition to this does it not (as far as I can gather) reperesent human motion.

 

[birly-shirly]

Wulsy - the contradiction is the difference between "bending the left wrist" and "the left wrist bending" in your earlier post then?

 

[wulsy]

Yes birls, it's in the same category - which movements/body positions are actively produced by the golfer and which occur as consequences of "external" forces.

24 words, Brian.

 

[drewyallop]

Here is another similar and gorgeous image.. Author is Miura, picture source is cited in picture

Michael,

Thanks for the diagram. I interpret it to mean that "Normal" is the instant that the tangenital component of CP acceleration reaches zero. Also, the radial component (centripetal force) begins increasing at a decreasing rate about half way down. Is it right then to say that the skilled golfer partially (wholly?) offsets the decreasing rate of CP acceleration by reducing the distance of the CP from the centre (of the bottom of the clavicles?). Can it be as simple as that?

Comments?

Drew

 

[Shot Limit]

Thanks for these last few pages guys.