Left leg at impact
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Dariusz J.
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Depends of one's individual RoM of lead knee joint. The smaller the RoM the more straight is the lead leg at impact because if the RoM limit has been achieved the leg straightens per se. One would need to use a proper amount of lead foot flare out angle either/or knee joint flexion depending on ones anatomy.
No. The firm lead side means there is no possibility to sway forward more. The only one alternative is to rotate or to lose balance. Watch face on Snead, Hogan and Nelson -- exactly in this order. All of them had firm lead side at impact but all of them differed because of different stances and individual anatomic nuances.
Cheers
Dear Curtisj76,
When joining this site I promised to only respond, not start any 'potentially self serving' questions. As a result, because of my belief of its CRUCIAL importance, I have been waiting, not so patiently, for a chance to discuss the characteristics of the left leg during the golf swing, not just at impact.
So please forgive me if this ends up deflecting others from answering your concerns. I purposely waited until the activity level slowed, and this string was only available by accessing the archive.
From the research/testing I have personally been involved in, I have concluded that without ANY measurement aids, ie video, 3D systems etc., the activity level and movement patterns of the left leg and especially the left foot can portray and predict the quality of the outcome of the shot. Let me provide some basic insights and examples.
Probably, many of us played baseball, and hopefully at some time even had home plate and first base umpires to call the game. In the case of the first base umpire, on close plays, it was important for him/her to stare at the base as the batter sped towards it, and LISTEN for the ball hitting the first baseman's glove to determine whether the batter or the ball got to first base first.
Why in the world would I wast your time bringing this up ??
Well, as a viewer or hopefully a help to a golfing friend, or to have some fun watching golf on TV, try JUST LOOKING AT THE LEFT FOOT AND LISTENING FOR IMPACT. You are in for a real education on no/little movement 'dynamic balance' from the professionals, and a whole lot of movement and 'dynamic imbalance' at the driving range or on the golf course even with the left foot partially off the ground when you hear impact. In addition, after impact, a lot of the time you will see the left foot, and then the right foot move inches, and even feet from their original position at address, an indication of a very serious dynamic balance problem. In fact, so serious that any degree of full swing consistency is IMO statistically impossible, meaning, each shot is simply an independent random event, since very little of the bodys machine-like movements are repeatable..
SO WHAT many of you might be thinking.
Well, the many proprioceptive sensing systems in the body detect the imbalances that are occurring during the down swing, and supply involuntary reflex reactions to support the bodies highest priorities of survival and balance, and yes, in golf IMO result in all that unwanted left leg and left foot movement.
BUT BIG CAUTION HERE, DO NOT just cement your left foot to the ground to attempt to solve this movement, go see your golf teaching pro seeking more lower and upper body dynamic stability (ie Bumpy back,keep it back, or, back to the target etc.), and volla, the left knee, ankle and foot will not only get quiet NATURALLY, but the foot will be planted on the ground at impact letting hundreds of pounds into the ground, and providing the dynamic stability we all need.
And by the way, this foot has most of the the job of arresting 3-5 horsepower (Dr. Steve Nesbitt's work) during the follow thru after impact, so it better be stable. IMO, if it is not prepared to do that, I BELIEVE the body learned that during the downswing, and sent a whole bunch of antagonistic reflex muscles in preparation for impact, significantly and negatively affecting the club head speed, path and even club face attitude/position at impact.
What do you all think ???
Damon Lucas
Super Moderator
Hi Art,
Good stuff!
Can you address the left foot's role from a power standpoint separately from an accuracy standpoint?
Specifically, with power, often the heel comes off the ground during the impact interval, with the balls of the feet bearing the weight and it is typically followed by a 'spin out' of one or both of the feet. Bad? Good? If you changed that player's foot action and related body actions, would you expect a loss of power with a less than 100% possibility that said player will regain or improve on their distance quotient.
With accuracy, most players don't utilize their kinematic sequence effectively anyway. Their release is typically a save from what goes on beforehand. How do you recommend that the implementation of improved left leg mechanics be combined with other 'accuracy and consistency providing' changes? Sequence wise?
Good stuff!
Can you address the left foot's role from a power standpoint separately from an accuracy standpoint?
Specifically, with power, often the heel comes off the ground during the impact interval, with the balls of the feet bearing the weight and it is typically followed by a 'spin out' of one or both of the feet. Bad? Good? If you changed that player's foot action and related body actions, would you expect a loss of power with a less than 100% possibility that said player will regain or improve on their distance quotient.
With accuracy, most players don't utilize their kinematic sequence effectively anyway. Their release is typically a save from what goes on beforehand. How do you recommend that the implementation of improved left leg mechanics be combined with other 'accuracy and consistency providing' changes? Sequence wise?
Having now had acl reconstruction and the medial meniscus removed in both knees due to non golf related injuries, I have come to the same conclusion as you have. I don't restrict any leg/knee/foot action, but I especially don't try to create any extra movements either.
Dear Damon,
This will be a lengthy reply, but I have a passion to be thorough in hopes that the areas we discuss will be of significant interest to warrant and receive additional scientific and research attention as requested by well respected folks like you.
I am both appreciative and flattered that you have read, addressed and asked the questions you have. I will do my best to both answer them AND be sure to define the pedigree of the research that supports my positions.
First the left foot power/accuracy question. ALL of my responses to this area are by personal observation and is anxiously awaiting some dual force plate verification as the left foot gets active during the downswing. My observations as recent as today show without exception that the left foot MUST be on the ground and stable at BEFORE IMPACT, or both the distance and accuracy will be negatively affected.
Now a bit of qualification; I know that Phil N., Bubba W, and several other currently active touring professionals lift their left foot, and many observers then conclude that is OK, and maybe even good for everybody. My interest these last 5 years has emphasized how the majority of the 50 million plus golfers can improve, not the characteristics of the elite few with incredible athletic talent.
So with that said, IMO, the accuracy, but more importantly the REPEATABILITY of full swings are ALWAYS negatively affected by the raising of the left heel AND the timing of replacing it on the ground. If that happens before impact, the errors are far less than if the left foot is back on the ground after impact.
Regarding power, it’s easy to conclude from Phil and Bubba, that more power can be delivered if the lead foot is raised during the back swing. For them, and other professionals I agree, since their next moves into transition, and up to the peaks of the kinematic sequence IMO develop significantly increased lower body dynamic stability, allowing them, to release more upper body, shoulder complex and arm power into the remaining downswing. For the rest of us however, the overall power is less if the lead foot is moving during the transition and downswing. Fortunately, now with Michael’s 3D system, a Trackman or FlightScope, and a camera with a reasonable shutter and frame speed, this area can move from hypothesis to golf truth. If a research or test program is of interest to you folks, I AM VERY WILLING AND ANXIOUS TO HELP AND PARTICIPATE IN ANY WAY I AM ASKED.
As you may already suspect from my many posts on lower body dynamic stability, for the testing already accomplished, it is clear that when the stability margins are increased, both the club head speed AND centeredness of impact improves to result in a higher ‘Smash Factor’, and ball speed AND a left foot, and leg reduced in activity level. Try it, have a student who lifts their left foot swing normally, then have them go thru the appropriate lower body ‘stability enhancing changes, (ie. Bumpy Back, back to the target, and possibly lowering their body by slightly bending their knees), and measure the changes with Trackman or FlightScope, while watching, hopefully video-ing a few swings. CAUTION, please don’t just ask the to keep their left foot on the ground, my experience is that the impact to other aspects of their swing is dramatic, and disruptive.
Regarding Spin Out, IMO, a clear sign of a best executed swing, is to be able to hold the finish WITH NO FOOT MOVEMENT AT ALL. This is obvious with almost all the folks on TV, and when I detect movement of a student when working with local pro’s like you, I suggest they have their students take repetitive swings WITHOUT A BALL at increasing energy levels, noting the build-up and increased difficulty of maintaining dynamic stability (and stability of their feet) at full swing levels. It is then easy to communicate that if the body is ‘thrown around’ by the forces developed during the swing, how can it be possible to make accurate contact with the ball there ??? So in summary Damon, spin out, or any foot relocation are clear signs that more dynamic balance and stability is MANDATORY.
If positive stability MARGIN is provided, as I explained above, my experience, and IMO that of Brian, Jon Hardesty and Billy McKinney, I believe was that their ‘Distance Quotient’ was definitely increased for both 7 irons and their drivers. (What is a distance quotient???)
Finally regarding the kinematic sequence question, I have only one example of how increased dynamic stability enhanced the kinematic sequence of a professional, but the test was conducted at The Golf Academy of America, as Phil Cheetham was Certifying the instructors on the use of the 12 sensor AMM system a few years ago. The Academies director of instruction produced 6 different swing styles and in summary, the dynamically balanced swing as evaluated by Phil and the instructors produced the best shaped kinematic sequence, and a increase in club head speed of 8% as calculated and presented in the 17 page report for each swing on the TPI/AMM system. Much more importantly however, Damon, I have absolutely NO hesitation in statin that 100% of the golfers I have guided in developing increased dynamic balance have demonstrated INCREASED DISTANCE AND REDUCED DISPERSION, and IMO, much of this comes from better organized kinematic sequencing, and sometimes requires attention to the golfers TEMPO consistency before increased dynamic stability can be reliably realized. Certainly more work needs to be done, and again I stand ready to help if asked.
I hope that folks like you push on the scientific communities to get busy researching these fruitful areas, for a huge percentage of the golfing world sincerely want to improve, and IMO the tools are available to help them.
Thanks for your questions, and I hope I helpd.
Regards,
art
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Art
Before learning the going normal / parametric handpath model that has been taught on this forum, I would have tended to agree 100%. For myself the normal force can be applied at various levels and on one extreme, it can be applied to the point of levitation of the whole body. It's been all positive so far for myself. The downwards force elements still applies, but in an earlier stage. So it may be swing-style dependant. Hoping this adds .
John
Before learning the going normal / parametric handpath model that has been taught on this forum, I would have tended to agree 100%. For myself the normal force can be applied at various levels and on one extreme, it can be applied to the point of levitation of the whole body. It's been all positive so far for myself. The downwards force elements still applies, but in an earlier stage. So it may be swing-style dependant. Hoping this adds .
John
Dear John,
Thanks for your comments, they did add, and reminded me that I forgot to mention the difference in potential left foot activity with the driver where there is the option to HIT UP on the ball, creating different ground reaction force timing for both feet.
In this driver situation, I have seen videos where both feet are off the ground at impact (LPGA), obviously providing the potential for significant 'going normal' forces, but also guaranteeing the left foot not on the ground at impact, and spinning out or just relocating the lead foot at 'touch down'. Unfortunately, my limited library of foot and ground reaction forces on dual force plates does not contain this type of swing. My guess is that there is a 'greater than body weight TOTAL FORCE from both feet after the peaks of the kinematic sequence, and a sort of well timed jumping action 'planned' for the down swing, after a descending (less than total body weight) motion during the back swing. TOO HARD FOR ME.
So I prefer, and see the 'going normal' force generation as a NATURAL result of the left shoulder 'trajectory' going almost vertically UP during the last 1/3 of the down swing time, and right after the pelvis, torso and lead arm angular velocity peaks of the kinematic sequence.
MICHAEL JACOBS' NEW AMM 3D TOY with synchronized force plates would be able to turn my hypothesis of these events into facts. In fact, the 'trajectory' of the left shoulder (humerus and glenoid) can be viewed from an infinite number of locations as the golfers 'avatar' representation progresses thru the swing. That system is also capable of retaining the image every '004 seconds producing a collage of movements over time, clearly showing this 'going vertical' of the lead shoulder.
I hope Michael reads this and comments on the incredible capabilities of the 3D system, and the potential of adding and sychronizeing his FlightScope and video for some major advances in understanding the intracies of the golf swing.
magicmarker
New
This is a right leg/foot at impact question but I'll put it here since the topic is still hot.
I sometimes have days where my right foot wants to slide straight behind me similar to a slap shot in hockey. The shots usually come off great, I'm just wondering what causes this potential instability. I've seen Tiger and Anthony Kim also do it on occasion before but not lately.
I'm curious if anything in this youtube video Brian Manzella Video Answer - Flat Right Foot - YouTube would need revision nowadays? My right foot isn't coming up though, it's sliding backwards for balance, if that makes any difference.
Makes me want to seek out a rare pair of metal spiked golf shoes, or sneak into a locker room on tour and take somebody elses.
I sometimes have days where my right foot wants to slide straight behind me similar to a slap shot in hockey. The shots usually come off great, I'm just wondering what causes this potential instability. I've seen Tiger and Anthony Kim also do it on occasion before but not lately.
I'm curious if anything in this youtube video Brian Manzella Video Answer - Flat Right Foot - YouTube would need revision nowadays? My right foot isn't coming up though, it's sliding backwards for balance, if that makes any difference.
Makes me want to seek out a rare pair of metal spiked golf shoes, or sneak into a locker room on tour and take somebody elses.
Damon Lucas
Super Moderator
Art,
Thanks for the replies!
Do you think that there is potential for more power if both feet 'jump' before impact? I am pondering on the direction of the force here - no need to worry about the exact location of the left shoulder. More jump than if the left heel stayed on the ground. Less concern about the proximal body parts in the downswing and hence sharper spikes nearer the bottom. Less interaction with the ground may mean more influence by the stronger upper body parts. Again, pure power, not accuracy.
Thanks for the replies!
Do you think that there is potential for more power if both feet 'jump' before impact? I am pondering on the direction of the force here - no need to worry about the exact location of the left shoulder. More jump than if the left heel stayed on the ground. Less concern about the proximal body parts in the downswing and hence sharper spikes nearer the bottom. Less interaction with the ground may mean more influence by the stronger upper body parts. Again, pure power, not accuracy.
Dear Damon,
Before answering whether or not more power can be generated with the feet off the ground a la a top speed right handed tennis forehand, I need to describe HOW AND WHERE I believe the power generation in a golf swing is developed distributed, and most importantly WHY.
Using the power values defined in Dr. Steve Nesbits 'work, power, energy studies in 2005, I have taken the analytical liberty of working backwards starting with the values at the wrist,elbow's, and Shoulders, assigning 'efficiencies' as I see the quality of the bio-mechanical movements, and comparing the resultant values of 'work; to that required to provide sufficient kinetic energy in the golf club head, to accomplish the recorded club head speed for each of the four subjects of the 80 or so he tested.
The absolute values of this approach are not nearly as important as the general conclusion that these body elements ALONE with believable bio-mechanical efficiencies, are sufficient to develop the club head speeds recorded.
Yes, if correct, or nearly correct, the torque generating capabilities across these body joints are sufficient WITHOUT THE TORSO OR PELVIC CONTRIBUTIONS to hit the ball as far as is NEEDED (but probably not wanted though).
I actually demonstrated this to some of your piers last year, as I hit my wedge as far and accurate with my sternum fixed at set-up and stably thru impact, after which I had a few 'horsepower' to slow down in the follow thru.
Do I propose this as the next fad to Stack and Tilt, H___ NO, but it certainly opened my mind as to the roles and power generation contributions from the torso and pelvis for an OPTIMUM SWING CONSIDERING INJURY POTENTIAL, DISTANCE, AND ACCURACY/DISPERSION.
So Damon, NO, I do not think that leaving the ground is the best way to develop power. I think OPTIMIZING the bodies torque producing elements of the body is my preferred approach. The beauty of this, is that the moments of inertia for the body parts accelerated by these internal torques quickly identify the shoulder complexes as potentially dominant places to concentrate as the torque to inertia ratios are the highest.
Sorry to be so lengthy and basic, but I know I am certainly in the minority, maybe even a radical, but I demonstrated this capability of producing equal distance , full swing to sternum stable swing just today for a skeptical teaching professional. Maybe I can get you and your teaching peers to try this and see if you generate 80, 90, or possibly 100 percent of the distance WITHOUT CONTRIBUTIONS from your torso or pelvis. I truly hope so, so we, TOGETHER can open the scientific studies to include seeking the BEST amount of torso and lower body rotation for each unique individual considering injury potential and performance.
COMMENTS PLEASE FROM EVERYONE READING THIS.
Respectfully and appreciatively,
art
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