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Wednesday, July 30, 2014

When Should You Initiate Weight Shift? - Dr. Michael Yessis







The Need To Clear the Hips by Dr. Michael Yessis is President of Sports Training

With the start of the U.S. Open today many golfers and golf fans will be watching their favorite pros. Most of them will be watching to see how far the ball goes, where it lands in the fairway, rough or on the green. Few however, will be looking closely, with an analytical mind, to how they execute the swing. For those of you who do I recommend that you look closely at how well they clear the hips. This is an action (really two actions) that they all execute — some much better than others well. The key elements to watch for are explained in the following article that I wrote for Senior Golfer.

To have an effective swing it is necessary to clear the hips. This is a recommendation that has little dispute among teaching pros. However, what constitutes clearing the hips, the roles that the hips play and the need for hip action in the total sequence of joint actions that occur in the swing are often misunderstood.

Clearing the hips consists of two major actions. First is weight shift (weight transference) followed by forward hip rotation. For a right handed golfer to execute weight transference, it is necessary to contract the muscles on the right side of the hips to push the hips forward while they remain level to the ground. This action is known as hip joint abduction. The more forcefully you drive the hips forward, the greater is the weight shift and the ensuing power that can be generated for eventual transfer into the hit.

Too much weight shift, however, can be a detriment as it may interfere with the following trunk rotation and arm actions or with balance. But it is generally agreed that weight should be shifted forward and that most of your weight should be on the forward leg during the downswing. This is needed for several very important reasons.

When you shift the weight onto the forward left leg, it then becomes the axis for hip rotation which begins as weight shift ends. When you then rotate the hips with the axis in the left leg, you will get maximum force generated in this action. If you only shift the weight partially so that it is equally distributed between both feet, the axis of rotation becomes your spine (middle of the hips) and the amount of power generated by the hip rotation is halved.

When your weight is over the forward leg, the medial rotator muscles of the left hip joint contract to rotate the entire pelvis forward. As a result, you produce a long hip lever which, in turn, creates more force. This is analogous to using a long club versus a short club. The longer the club (which acts as a lever), the more the force that you can generate.

When your weight is shifted half-way so that the spine is the axis of rotation, the medial rotators of the left and the lateral rotators of the right hip joint contract to rotate the hips. In this case, your right hip rotates forward while the left hip rotates backward. Thus you have a shorter effective lever which is not capable of generating maximum force. In this case, it is half of what can be generated with a full lever hip turn. When your weight is shifted half-way so that the spine is the axis of rotation, the medial rotators of the left and the lateral rotators of the right hip joint contract to rotate the hips. In this case, your right hip rotates forward while the left hip rotates backward. Thus you have a shorter effective lever which is not capable of generating maximum force. In this case, it is half of what can be generated with a full lever hip turn.

Thus, when you have full weight shift (a strong, full hip slide) prior to hip rotation you can create more power. This in turn equals greater distance. If you look at most long ball hitters you will see that they have full weight shift before rotating the hips.

Dr. Michael Yessis is President of Sports Training, Inc. a multi-faceted company specializing in biomechanical/kinesiological analyses, and specialized training and specialized equipment for explosive speed and quickness. Dr. Yessis is Professor Emeritus at California State University, Fullerton. He is a clinical advisor and a member of the editorial board for the American Running Association.

Dr. Yessis received his Ph.D. from the University of Southern California. He was the first to show the relationships between muscular strength and endurance in his research. He taught on the university level for over 35 years in the areas of biomechanics (technique analysis), kinesiology (muscle and joint movements) and exercise science. In addition he was Editor-in-Chief of the Fitness and Sports Review International.

Dr. Yessis is the foremost U.S. expert on Russian training methods He has been to Russia multiple times, worked with their coaches such as Yuri Verkhoshansky, and has translated and publis
hed Russian training articles in the Fitness and Sports Review International for over 29 years.


Note: There are timing and location adjustments on almost all pitches in the baseball swing that won't allow for early weight shift. Since the ball is on the ground and stationary, the timing adjustment is very small so the weight shift and location of contact is consistent in a golf swing. The loft on the club makes it neccessary to swing down to get the ball to go up, it is not the case with a baseball swing. ( difference between weight shift before rotation relative to golf versus baseball) 


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XLAthlete Articles:
When you should drive off the rear leg to produce power in the swing is often debated.
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Here is a post from Dr. Michael Yessis on weight shift.

When Should You Initiate Weight Shift?

When you should drive off the rear leg to produce power in the swing is often debated. This applies to not only to the swing in golf but also to baseball, tennis and other sports in which you swing an implement to hit a ball or other object. According to some professional instructors you should drive off your rear leg late in the swing to produce more forward weight shift.

This 'springboard effect' as they call it, supplies extra clubhead, bat or racket speed and ultimately more power and/or distance. Is this, however, a sound recommendation? Does driving off the rear leg to shift weight forward late in the swing really add more power or distance or does it interfere with accuracy and force? For example, this recommendation is contrary to what occurs in executing an effective swing or hit as determined by physics (biomechanics) and swing technique analyses. It has been well substantiated that the drive off the rear leg occurs at the beginning of the power phase of the swing (when you generate the force needed in execution of the skill).

This force, produced by shifting the hips forward, is usually directed toward the target and initiated after completion of the backswing. The drive off the rear leg is partially responsible for this force but mostly it comes from hip abduction in order to shift the hips forward to initiate the downswing in golf or forward swing in baseball and tennis. In this action weight from the rear leg is transferred to the front leg as the hips are driven forward.

For the rest of the post, visit the xlathlete.com website.

Sincerely,
Cal Dietz of Xlathlete.com
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When Should You Initiate Weight Shift?

When you should drive off the rear leg to produce power in the swing is often debated. This applies to not only to the swing in golf but also to baseball, tennis and other sports in which you swing an implement to hit a ball or other object. According to some professional instructors you should drive off your rear leg late in the swing to produce more forward weight shift.
This 'springboard effect' as they call it, supplies extra clubhead, bat or racket speed and ultimately more power and/or distance. Is this, however, a sound recommendation? Does driving off the rear leg to shift weight forward late in the swing really add more power or distance or does it interfere with accuracy and force? For example, this recommendation is contrary to what occurs in executing an effective swing or hit as determined by physics (biomechanics) and swing technique analyses. It has been well substantiated that the drive off the rear leg occurs at the beginning of the power phase of the swing (when you generate the force needed in execution of the skill).
This force, produced by shifting the hips forward, is usually directed toward the target and initiated after completion of the backswing. The drive off the rear leg is partially responsible for this force but mostly it comes from hip abduction in order to shift the hips forward to initiate the downswing in golf or forward swing in baseball and tennis. In this action weight from the rear leg is transferred to the front leg as the hips are driven forward.
This action is commonly known as weight shift and is the first action to generate force in the power phase.  In other words, the hips come through early in the swing to set up the kinetic chain actions that follow in sequence.  If you drive the hips forward after you are well into the power phase it will contribute very little, if any, force to the hit.
Keep in mind that at this time (late in the swing) you have already turned the shoulders and the arms are bringing the hitting implement into the contact area.
By having a late drive off the legs, you do not start the swing with the generation of force that can be transferred into each sequential joint action. Force that can be transferred must be initiated early in the swing.

Driving the hips forward at the beginning of the power phase can be a substantial force especially when combined with a hip turn as the forward hip drive is diminishing. This is known as clearing the hips or getting the hips into the hit or swing. It sets you up for maximum production of force in the following torso and upper limb actions.
Some of the best golfers, baseball hitters and tennis groundstroke players are classic examples of getting the hips cleared early in the swing before the arms begin their action.  However, keep in mind that the arms may be in motion because the shoulders bring them around.  This does not mean that they initiate the arm action since it happens later when the shoulders are concluding their power phase actions.
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Should the Hips Shift Before They Turn? | Steve Pratt's ...
Learn the Mike Austin golf swing from home and hit longer straighter drives!
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I have written before on this subject.  The shift and turn of the hips makes up the downswing portion of the compound pivot in the Mike Austin swing.  Just like a baseball pitcher, the hips should shift laterally before turning.  Dr. Michael Yessis agrees, writing:
'Do you initiate the down - forward - swing with weight shift? Do you rotate the hips before you shift your weight forward? Do you rotate and shift weight simultaneously?
Most golfers and baseball players answer these questions without looking at their swing. One reason for this comes from the articles written in many magazines that tell them what to do. As a result, they may be missing out on creating the most favorable swing, one that will give them the greatest distance and placement.
Although golfers and baseball players debate which action should come first in the forward swing - weight shift or hip rotation - it is really a non-debatable question if you trust science. From biomechanics, which is mostly physics in nature, we know that weight shift should precede hip rotation.
This is needed for several very important reasons. First, it is a way of getting the body into motion. This action is used in almost all sports that require the production of force. In general, the greater or more forceful the weight shift, the greater will be the production of force.
Thus, the hips should start the forward swing by shifting laterally to the left. As the lateral shift ends, hip rotation to the left (right-handed player) should begin. This is seen in all great players and especially those who hit the long ball well consistently.
When your weight is shifted on to the front leg it creates a more favorable axis for hip rotation. With the weight on the front leg you can generate the greatest amount of force from the hip rotation. If the hip rotation takes place simultaneously with the lateral shifting of the hips, the total force is greatly diminished.'
The conventional swing relies on turning the hips either simultaneously with the shift, or turning without shifting at all.  Not only will these players hit with less power, but they will not be as accurate either.

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Physical Preparation of a Quarterback: Dr. Yessis Projec...
I was fortunate enough to call upon the efforts of Dr. Yessis to help find out the root mechanical cause in Troy's throwing and come up with a program to i...
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"It is in the transfer of training that the learning and improvement of technique and likewise the development of the related or other physical qualities (abilities) take place." —Dr. Anatoly Bondarchuk, Transfer of Training, Vol.1
Background
In September 2010, during the second game of the season, junior quarterback, Troy Green, suffered an avulsion fracture of the medial epicondyle of his right elbow while throwing a pass in the second half of a football game. He had been experiencing pain in his throwing elbow on and off since the eighth grade. Initially, his coaches thought he had a "problem with his mechanics," but they were never able to diagnose and/or fix the mechanical root cause of the pain. Then during the summer of 2010, in the process of learning a new offense that utilized much more passing than Troy was used to, he overused his arm. This, coupled with poor mechanics, caused him to sustain a stress fracture of the medial epicondyle of his throwing arm diagnosed by sports orthopedist Marc Pietropaoli, MD. After extensive consultation, including world renowned sports orthopedist, Dr. James Andrews, it was elected to allow Troy to continue throwing. However, Dr. Andrews warned that if Troy continued to throw through the pain, he could suffer an avulsion fracture. Dr. Andrews stated that he had seen medial epicondyle avulsion fractures in baseball pitchers but never in a football quarterback. Unfortunately, Troy did indeed eventually avulse his medial epicondyle. On September 13, 2010, Troy underwent surgery by Dr. Pietropaoli of Victory Sports Medicine & Orthopedics to place a screw in his epicondyle to line it back up and allow it to heal properly.
This January Troy had the screw removed from his elbow and was allowed to start training his upper body gradually. He wasn't able to throw until March. That is when I (his physical preparation coach) was fortunate enough to call upon the efforts of Dr. Yessis to help find out the root mechanical cause in Troy's throwing and come up with a program to improve him.
Programming and organization
Dr. Yessis places the biodynamic structure of the athlete for their sport in the forefront and then from a biomechanical perspective is able to analyze the athlete to find out what has to be improved to make his skill of execution more effective. He then programs the training. Dr. Yessis is able to break down the total technique into its smallest components and develops special exercises that improve and strengthen those particular actions.
I have found this to be truly amazing because it has cut down the total volume of Troy's training. He has improved in his speed, agility, and throwing thus far without spending any time fully sprinting, performing any agility drills, and throwing.
Dr. Yessis's biggest teaching point is the importance of coupling strength and technique together. Improving technique alone can enhance performance. An increase in strength doesn't necessarily equate to better performance. Strengthening specific joint actions of the technique used in the sporting act (dynamic correspondence) will then make the athlete stronger and also improve his technique. In no way am I undermining the importance of general strength, but that can only take you so far. Unfortunately, strength gain and athletic performance improvement aren't linear.
"The specific motor potential of an athlete depends on the total quantity of mechanical work that can be produced by his motor system, transforming the force of muscular contractions into the specific movements, which compose the competition exercises. Thus, to increase the athlete's motor potential, it is necessary to increase the force generating capacity of the muscles involved in the execution of competition exercise." —Dr. Yuri Verkhoshanksky, Special Strength Training Manual for Coaches
Project continued
Since our visit with Dr. Yessis, he has torn down Troy's throwing motion, and Troy has been working really hard building it up from scratch. Within the first five minutes of working with Dr. Yessis, he was able to point out the key mechanical flaw as well as many related flaws that Dr. Yessis said contributed to Troy's elbow injury. I have to admit that we were amazed at how accurate Dr. Yessis's diagnosis was. Dr. Yessis was able to not only point out the flaws, but he was able to show us technical movements and special exercises to fix each particular joint action of Troy's throwing motion (weight shift, hip rotation, shoulder rotation, arm cocking, medial rotation, and follow through).
For example, one particular mechanical flaw of Troy's throwing was that he never separated his hips from his shoulders during the throwing, so he was unable to generate much power from his lower body. Dr. Yessis stresses the importance of this separation in order to create a summation of forces. By rotating the hips while keeping the shoulders back, the obliques are placed on an eccentric stretch. Thus, when the hips decelerate, the shoulder girdle begins to rotate, creating a whipping action. The axis of rotation for the shoulder girdle is through the left shoulder, which produces a long force arm.
"The hip rotation is a key action in throwing. It should occur as weight shift ends and before shoulder rotation begins. Keep these movements separate and combine them sequentially so that as one action ends the next action begins." —Dr. Michael Yessis, Build a Better Athlete.
In order to help Troy unconsciously learn this separation, Dr. Yessis had Troy perform this technique using the part/whole method (working on the part and then incorporating it into the whole). To improve the strength and the speed of the separation/rotation of the hips from the shoulders, Troy is performing special exercises (special preparatory and special developmental) with the active cords. This has improved Troy's throwing tremendously in a short period of time.
Dr. Yessis also created the T-bench medial rotation exercise to duplicate the arm action as it occurs in the throw and a specialized exercise that forced Troy to get the hips around before the shoulders. The latter exercise was performed with active cords as was the exercise for weight shift. There are quite a few other exercises that Dr. Yessis created that work the muscles as they are used in the throwing action.
For Troy's running and acceleration mechanics, Dr. Yessis observed that Troy lacked sufficient knee drive strength. The knee drive is the joint action of the hips after the ankle joint extension during the push off to drive the thigh forward by the hip flexors. The greater the strength and speed of the knee drive, the greater the stride frequency as well as greater force for whipping out the shin for the pawback action (greater stride length).
In order for Troy to improve the knee drive, special exercises are used to duplicate this using active cords with the leg (knee and hip) starting behind the body. In Dr. Verkhoshansky's books, particularly in his new book (Special Strength Training Manual for Coaches) on page 53, he shows an illustration of "swing leg flexion with the take off leg extension from the hip joint."
Dr. Verkhoshansky explains how the principle of dynamic correspondence is applied in "selecting local special strength training means finalized at increasing the working effect of key movements of competition exercise." This illustration is an example of how to increase the knee drive action for running. Yet, for some reason, coaches who view Dr. Verkhoshansky as one of the top minds ever in the sports science field disregard this and other particular dynamic correspondence exercises for whatever particular reason.
For many years now, Dr. Yessis has preached the significance of this exercise for improving running speed with active cords, which allow you to safely and gradually apply an appropriate level of external resistance. For whatever reason, very few have ever listened. I think one reason could be that the exercises are very cumbersome to perform. It was probably good in the 1970s, but Dr. Yessis, with his expertise in biomechanics and kinesiology, has modernized these exercises with the use of active cords. These exercises can be seen in his second edition of Explosive Running.
I have used these with my other athletes, particularly the ones who ran like Fred Flintstone, and have found that they've improved their running mechanics and speed significantly, taking tenths off their 40 times.
With the season quickly approaching, Dr. Yessis is ramping up Troy's training. Some of the special exercises will then serve a different role as the program intensifies and readies Troy. The knowledge that I have learned from Dr. Yessis in this short period of time has helped me to develop better programs for my other athletes. Head coach Tim Green, Troy, and I have been blown away with the results thus far.



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