Jim McLean's 6 degree-of-freedom 3D report and other pevis/hips commentary
- Thread starter Brian Manzella
- Start date
- Status
Why do you disagree? Do you think the graphs are wrong? If so, how are they wrong? You honestly believe the body is more efficient without a certain sequence?
natep
New
Deceleration is being taught here? I don't think I have ever heard that being taught here.
Proximal to distal...the hip turn is what, about 2-3 mph, shoulders/torso a little more. Clubhead is what?
What are you proposing to be taught? Keep the body as still as possible and swing the arms and club only? What sequence do you see as optimal?
Last edited:
What is your theory/explanation of the use of the body to generate maximum speed. Each sequence is personal to the golfer? Nothing is efficient? We can't know anything with 3D graphs? Shoulders should fire first? Hands?
Last edited:
Who is teaching this? Certainly not Brian when I had two lessons with him this year. He noticed correctly that my pelvis was not being used efficiently.
lia41985
New member
Last edited:
So, just because deceleration of the hips happens in high quality swings, you are saying that is what is being taught? and by Brian too? Ever hear of feel versus real?
According to Michael Jacobs, good players will have their hips closed approximately 40 deg. at the end of the back swing. They then have their hips approximately 40 degrees open at impact. That means the hips have rotated approximately 80 degrees from the top of the back swing to impact. It would be very difficult to achieve those numbers while trying to decelerate the hips.
Next you're going to be saying that a player can open the club face while the ball is in contact with it to keep from hooking.
Last edited:
birly-shirly
New
I agree with this. I still would like to understand why the McLean graphs represent an "elephant in the room".
I have faith that this can be explained to me in conventional prose...
mgranato
New
Analyzing the Golf Swing in 6 Degrees of Freedom with AMM 6DOF Systems
by PHILCHEETHAM on JUNE 6, 2012
What is 6DOF?
Six-degrees-of-freedom (6DOF) means you can move six ways; forward/backward, left/right, up/down; these movements are linear, determine your position and are measured in feet, inches, meters etc. You can also turn, plus bend forward/backward or side to side; these movements are angular, determine your orientation and are measured in degrees.
When you measure something you first need to measure it from something else; that “something else” is called the reference point or reference frame and is considered the (0, 0, 0) point. You can measure any other point from that point by going forward, sideways and up; or, of course backwards, sideways and down and in any order. As I said earlier, these movements are measured in feet, inches, meters, etc. These three-dimensions account for three of the 6DOF we are discussing.
Once you have moved to that position by moving in three-dimensions, you can change your orientation and bend forward, sideways or turn; orientation is measured in degrees. These are another three degrees of freedom. So the three position movements and the three angle movements make up the 6DOF.
How is this important to the golf swing? Every part of your body can be considered to move with 6DOF, for example, your pelvis (hips) at the address position will have a certain position and orientation and that will be a different position/orientation to the top of backswing and again different to impact and finish. So at the top of your backswing your hips will have turned, tipped sideways and tilted backwards. They may also have swayed sideways, thrust forward and lifted up compared to where you were at address. So to get all the motions we need to measure all six of these values; we need to measure in 6DOF.
By the way, your spine is not stiff during the golf swing; it is flexible and so your pelvis and thorax can move independently of each other; yes, in 6DOF. (Note; we use the term “thorax” to mean upper body or ribcage. Please see the explanation at the end of this article). You don’t only turn your spine during a swing; you bend and side-bend as well. In fact this is where you get a huge amount of your power from, but unfortunately if strength is not maintained it is also how back injuries occur. So, measuring these two prime movers (pelvis and thorax) in 6DOF during the swing is very important. Several systems out there today only measure angles (3DOF); they are missing half of the picture!
AMM 6DOF Systems
Advanced Motion Measurement, Inc., (AMM) has several systems that can measure 6DOF during the golf swing. They all include the TPI 3D biomechanics methodology. They range from the comprehensive full body AMM3D motion capture system using 12 electromagnetic sensors attached to your limbs, head and body; to the new three sensor Walkabout 6D Golf system that measures the club, pelvis and thorax.
Surprisingly with only three sensors the Walkabout system measures many important aspects of the swing in 6DOF. I’ll discuss these systems subsequently but first I want to explain the Kinematic Sequence.
The Kinematic Sequence
All of the AMM systems measure the Kinematic Sequence of the body during the swing. This gives us a measure of the dynamic efficiency of the swing. It tells us how we are generating energy and whether we are doing it in the best possible way. The Kinematic Sequence is a measure of the turning speed of the pelvis and thorax, plus the swing speed of the arms and club shaft. It is a graph of these curves, (sometimes others may be added). An example is shown below.
There is a huge amount of information in just these four curves. We can tell the sequence of motion in your takeaway. We can tell the sequence of motion in you transition from backswing to downswing. The transition sequence is very important in power generation because of the way that muscles work. If a muscle is stretched before it contracts then it can contract stronger. This is called the stretch-shorten cycle of muscle. So if we see your pelvis transition before your upper body then we know that there is an extra stretch going on in your mid-section, helping those muscles to provide more power. The same extra stretch can occur at the shoulder joints and the wrist joints, and we can measure that too.
Surprisingly to some, during the downswing your body doesn’t accelerate all the way in to impact, only the club does. Actually each part of your body first accelerates in the downswing, and then decelerates just before impact. This happens naturally and is similar to “cracking a whip”. First the handle of the whip speeds up then it sharply slows down in order to transmit the energy to the tip of the whip so that it cracks. The analogy of the golf swing to this is not perfect but it is instructive. So in the golf swing all parts of your body and the club speed up during the early part of the downswing (as indicated by the up-slope of all four curves) but after a few fractions of a second the pelvis slows down and speed is transferred and increased across the core by the mid-section muscles. This allows the upper body to be “sling-shot” faster into the downswing. This sequence then repeats, with the upper body slowing down as the arms continue to speed up; energy is created and transmitted across the shoulder joint to speed up the arms. Next the arms slow down as the club is released into the ball with maximum possible speed. The characteristics of this downswing sequence are:
first acceleration then deceleration,
each segment’s speed peaks and decelerates after the previous one in a sequential manner,
each segment’s speed peaks higher than the previous one, with speed being gained across each joint, caused by the timely action of the muscles across that joint.
In the picture below you can see all the kinematic sequence parameters that were measured and compared between novice and elite golfers in our research that was published in the World Scientific Congress of Golf proceedings (Cheetham, et. al., 2008), they include; accelerations, decelerations, timing of peak velocities, values of peak velocities, speed gain from segment to segment, and calculated club head linear speed.
by PHILCHEETHAM on JUNE 6, 2012
What is 6DOF?
Six-degrees-of-freedom (6DOF) means you can move six ways; forward/backward, left/right, up/down; these movements are linear, determine your position and are measured in feet, inches, meters etc. You can also turn, plus bend forward/backward or side to side; these movements are angular, determine your orientation and are measured in degrees.
When you measure something you first need to measure it from something else; that “something else” is called the reference point or reference frame and is considered the (0, 0, 0) point. You can measure any other point from that point by going forward, sideways and up; or, of course backwards, sideways and down and in any order. As I said earlier, these movements are measured in feet, inches, meters, etc. These three-dimensions account for three of the 6DOF we are discussing.
Once you have moved to that position by moving in three-dimensions, you can change your orientation and bend forward, sideways or turn; orientation is measured in degrees. These are another three degrees of freedom. So the three position movements and the three angle movements make up the 6DOF.
How is this important to the golf swing? Every part of your body can be considered to move with 6DOF, for example, your pelvis (hips) at the address position will have a certain position and orientation and that will be a different position/orientation to the top of backswing and again different to impact and finish. So at the top of your backswing your hips will have turned, tipped sideways and tilted backwards. They may also have swayed sideways, thrust forward and lifted up compared to where you were at address. So to get all the motions we need to measure all six of these values; we need to measure in 6DOF.
By the way, your spine is not stiff during the golf swing; it is flexible and so your pelvis and thorax can move independently of each other; yes, in 6DOF. (Note; we use the term “thorax” to mean upper body or ribcage. Please see the explanation at the end of this article). You don’t only turn your spine during a swing; you bend and side-bend as well. In fact this is where you get a huge amount of your power from, but unfortunately if strength is not maintained it is also how back injuries occur. So, measuring these two prime movers (pelvis and thorax) in 6DOF during the swing is very important. Several systems out there today only measure angles (3DOF); they are missing half of the picture!
AMM 6DOF Systems
Advanced Motion Measurement, Inc., (AMM) has several systems that can measure 6DOF during the golf swing. They all include the TPI 3D biomechanics methodology. They range from the comprehensive full body AMM3D motion capture system using 12 electromagnetic sensors attached to your limbs, head and body; to the new three sensor Walkabout 6D Golf system that measures the club, pelvis and thorax.
Surprisingly with only three sensors the Walkabout system measures many important aspects of the swing in 6DOF. I’ll discuss these systems subsequently but first I want to explain the Kinematic Sequence.
The Kinematic Sequence
All of the AMM systems measure the Kinematic Sequence of the body during the swing. This gives us a measure of the dynamic efficiency of the swing. It tells us how we are generating energy and whether we are doing it in the best possible way. The Kinematic Sequence is a measure of the turning speed of the pelvis and thorax, plus the swing speed of the arms and club shaft. It is a graph of these curves, (sometimes others may be added). An example is shown below.
There is a huge amount of information in just these four curves. We can tell the sequence of motion in your takeaway. We can tell the sequence of motion in you transition from backswing to downswing. The transition sequence is very important in power generation because of the way that muscles work. If a muscle is stretched before it contracts then it can contract stronger. This is called the stretch-shorten cycle of muscle. So if we see your pelvis transition before your upper body then we know that there is an extra stretch going on in your mid-section, helping those muscles to provide more power. The same extra stretch can occur at the shoulder joints and the wrist joints, and we can measure that too.
Surprisingly to some, during the downswing your body doesn’t accelerate all the way in to impact, only the club does. Actually each part of your body first accelerates in the downswing, and then decelerates just before impact. This happens naturally and is similar to “cracking a whip”. First the handle of the whip speeds up then it sharply slows down in order to transmit the energy to the tip of the whip so that it cracks. The analogy of the golf swing to this is not perfect but it is instructive. So in the golf swing all parts of your body and the club speed up during the early part of the downswing (as indicated by the up-slope of all four curves) but after a few fractions of a second the pelvis slows down and speed is transferred and increased across the core by the mid-section muscles. This allows the upper body to be “sling-shot” faster into the downswing. This sequence then repeats, with the upper body slowing down as the arms continue to speed up; energy is created and transmitted across the shoulder joint to speed up the arms. Next the arms slow down as the club is released into the ball with maximum possible speed. The characteristics of this downswing sequence are:
first acceleration then deceleration,
each segment’s speed peaks and decelerates after the previous one in a sequential manner,
each segment’s speed peaks higher than the previous one, with speed being gained across each joint, caused by the timely action of the muscles across that joint.
In the picture below you can see all the kinematic sequence parameters that were measured and compared between novice and elite golfers in our research that was published in the World Scientific Congress of Golf proceedings (Cheetham, et. al., 2008), they include; accelerations, decelerations, timing of peak velocities, values of peak velocities, speed gain from segment to segment, and calculated club head linear speed.
Lia -
Have you been drinking too much egg nog? Next you'll infer that Brian is teaching a hip stall from his obvious comment about the kinematic sequence reference WHERE THE HIPS DECELERATE FROM THEIR PRIOR PEAK SPEED IN HIGH QUALITY SWINGS. Are you from Findland? I know only one other person on golfing forums who can butcher our language so bad to come up with such whacky ideas and claim he's right.
Have you been drinking too much egg nog? Next you'll infer that Brian is teaching a hip stall from his obvious comment about the kinematic sequence reference WHERE THE HIPS DECELERATE FROM THEIR PRIOR PEAK SPEED IN HIGH QUALITY SWINGS. Are you from Findland? I know only one other person on golfing forums who can butcher our language so bad to come up with such whacky ideas and claim he's right.
You need a high caliber swing first before decel would even be on anyone's radar.(Or ones hips just fire with no timing whatsoever). You can't seem to even figure that out as a condition precedent. The decel is for more speed. Brian teaches his students individually. Did someone hack your account? Next you'll conduct a research a thon without a control group.
Last edited:
lia41985
New member
To paraphrase Hebron, we play to learn. We don't learn to play.
Robbierob99
New
Shouldn't the take home of BRIAN's original post be something along the lines of when you give a decent golfer more precise instruction they can make meaningful improvements on the spot.
Video = Hacksaw (we can disagree on the usefulness of video or not, but we should all agree that its not exactly the most precise tool out there)
Trackman = Surgical Scalpel
Force Plates = another Surgical Scalpel
6DoF machine = Surgical Laser
Video (optional), Trackman, Force Plates, 6DoF Machine running at same time = as close to a magic bullet as we can get right now.
Video = Hacksaw (we can disagree on the usefulness of video or not, but we should all agree that its not exactly the most precise tool out there)
Trackman = Surgical Scalpel
Force Plates = another Surgical Scalpel
6DoF machine = Surgical Laser
Video (optional), Trackman, Force Plates, 6DoF Machine running at same time = as close to a magic bullet as we can get right now.
Lindsey Newman
New
Me personally?.....
Never witnessed one player get better solely focusing on hips and how they rotate. Not one.
Never witnessed one player get better solely focusing on hips and how they rotate. Not one.
mgranato
New
Two weeks ago I would have completely agreed with this.
- Status