Commensurate Effort
Jerking the barbell successfully on the 3rd attempt in competition is the most difficult and complex skill in weightlifting sport. Typically, the success rate of the 3rd attempt in the clean and jerk at international, continental and national competitions is under 40%; sometimes even less than 30% (Charniga, A., “Power, Equilibrium and the Struggle with Horizontal Gravity”). This is rather dismal figure given that the weightlifter has only three attempts; and, the 3rd, the most crucial attempt; can decide the entire outcome of the competition.
Jerking a big weight from the chest efficiently is contingent on two basic prerequisites:
/ to generate the necessary power to raise the barbell high enough to fix it according to the technical rules;
/ balance the athlete – barbell system.
It should not come a surprise balance/equilibrium is the most difficult sine qua non.
A weightlifter who is able to clean a heavy weight essentially has the power to jerk it; because more power to jerk the weight has already been expressed in cleaning the weight (Kanyevsky, 2007). Consequently, how one allots the power of lifting with the requisite balance/equilibrium is crucial to a positive outcome.
Balance is very complex task for the weightlifter. The classic exercises involve rapid switching of direction from multiple postures. The a lifter has to establish equilibrium in the most difficult posture for balance; the starting position for the jerk; after cleaning the barbell. A struggle to stand with a big weight makes this all the more a challenge.
It is generally agreed, a basic rule of thumb for assuming the correct starting posture after rising from the squat is to place the feet about hip width apart; toes turned out slightly (Roman, Vorobeyev, Zhekov, Ivanov). However, the lifter’s stance can vary from feet almost touching to considerably wider than hip width.
The human body has radial symmetry; think DaVinci’s drawing of Vitruvian man. That is to say, right and left sides of the body are of equivalent dimension; each half a mirror of the other; equidistant from the midline. Consequently, one can assume the forces of the muscles exerted on the barbell will be symmetrical by placing the hands on the bar equidistant from the center and likewise the feet equidistant from the center of the bar.
This of course sounds good on paper. However, the dynamics of the real world are not on paper. For instance, it is not uncommon for a lifter to unconsciously place the feet in the starting position of the jerk with one foot slightly in front of the other; an asymmetric stance. On the surface it appears to be an error. In theory, for the weightlifter’s radially symmetrical body to apply force uniformly to the barbell, i.e., so the forces from the lifter’s muscles are balanced; the and hands and feet should be equidistant from the middle of the bar. Likewise the mid-line of the body should intersect roughly through the middle of the barbell.
Coach and athlete should bear in mind, regardless how careful one places the hands, the feet and the general disposition of the mid-line of the body relative to the middle of the barbell:
- the lifter still has to ‘find balance’;
- forces from the athlete’s muscles are not necessarily symmetrical, or, the signals from the central nervous system to upper and lower extremities are automatically in sync:
“The majority of coaches and sportsmen are unaware a lifter does not utilize the strength of the muscles of the right and left side of the body uniformly.” A.N. Vorobeyev, 1988
Furthermore, for reasons unknown, no such thing as perfect symmetry exists; uniformity of efferent signals to muscles, relative strength of the major muscle groups and so forth. Furthermore, the weightlifter still has to find balance/equilibrium with barbells of varying weight.
The single most critical factor to reliability in the jerk; especially on the crucial 3rd attempt in competition; is finding one’s balance/equilibrium. This means one has to learn the correct skills by means of:
/ a learning sequence for the athlete develop the skill to focus on fixing the weight: find the balance; establish equilibrium.
The second factor on the path to reliability is to learn to commensurate effort suitable to both ‘find balance’ and generate the power of lifting needed to raise the barbell. To this end one has to find:
/ a simplified method of producing the power to jerk the barbell: commensurate effort to moving the body to the end, i.e, fixation of the barbell.
Building Blocks: An irrational application of an old ‘Soviet sequence’
Sometimes it is useful to know what not to do; in order to better understand what one should do in order to learn the most effective skills.
The following video consists of a coach teaching a young female lifter how to perform the split style (scissoring the feet) jerk. There are a number of good examples in the video of how not to ‘find your balance’ {establish equilibrium}; how not to integrate balance with a commensurate effort of lifting.
{Chinese video courtesy Hookgrip}
In the video, the lifter stands astride a cross drawn on the floor with two boxes; one in front of the lifter, the other behind; on either side of the vertical intersecting line. This chalk outline is meant to be a guide for the starting point as well as a guide for the lifter to move her feet from start to finish. In the starting position, the athlete’s places her feet on each side of the vertical line; aligned with the mid-line of the body; toes are just behind the horizontal line. This ‘line – guide’ technique illustrated in the video reveals a number of false assumptions of how to learn correct technique.
The 1st false assumption. Presumably moving from and to pre – determined lines on the floor will teach the athlete the commensurate effort to raise the barbell and ‘find balance’ to lift it.
/ the lifter is forced to start from behind a horizontal line; such that her feet are strictly parallel just behind the line:
The assumption presented here is that placing feet behind a straight line is appropriate for this or any athlete; and, one need not allow for individual variations. A ‘man made’ arrangement of feet can inhibit a lifter from developing the complex skill of ‘finding balance’; through kinesthetic sensation. An individually selected disposition of the feet at the start is crucial for a successful jerk (Ivanov, 1971).
The 2nd false assumption. Learn the exercise through a step – by – step sequence of mechanical movements to accelerate the barbell.
/ the coach tells the lifter to fully straighten legs; rise onto her toes and raise her hands (as if they were holding a barbell); then jump up to scissors; in a mechanical step – by – step fashion;
Following the coach’s instructions, with feet disposed in a horizontal line; the lifter mechanically bends knees, straightens knees; raises her heels and elevates the hands above the chest to perform the drive phase of the jerk.
The athlete’s mechanized movements are incorrect because they are not a true representation of what actually happens; or, should happen for that matter. For instance, the switch from straightening to scissoring the legs should begin with the knees slightly bent (Zhekov, 1976). Trying to fully straighten the knees is incorrect. Despite what one can observe from still pictures; fully straightening knees should result from the inertia of a powerful leg drive (Zhekov, 1976); the lifter should already be switching to scissoring before the knees have straightened.
An intentional full extension of the legs in excess of a knee angle of 165⁰ involves extra, unproductive effort (Zatsiorsky, Bobbert) and delays the switch to dropping under the barbell (Zhekov, 1976). Furthermore, the calf muscles are relegated the role of raising the heels after fully straightening the knees and trunk. This limited role neglects the significant potential of the these muscles and especially the Achilles tendon to enhance the effectiveness of the leg drive. Heel raise can not only occur before full extension; but, with heels raised slightly; more power is produced pushing off the toe – to – hip ‘leg spring’.
The 3rd false assumption. Scissoring the legs, or splitting, under the barbell is a lowering/receiving motion and the action does not impart an upward acceleration on the barbell.
/ the coach instructs the lifter to perform the scissoring as a lowering /receiving motion to fix the barbell overhead.
Figure 1. Olympic champion jerking a heavy weight with left foot leaves the platform before the right. The left foot has further to move before it is fixed to the floor; meanwhile the right foot remains in contact with the platform briefly before shifting forward. Charniga photo.
Scissoring the legs to drop under the barbell effectively should impart additional acceleration to the barbell; while at one and the same time; it is a preparation to receive the barbell at arms – length. The coach instructs the athlete in the video to “jump up” to scissors the legs. Presumably both feet are to leave the floor simultaneously. This is not what happens in performing the exercise. The foot to be shifted backwards in the split (generally the left leg of right handed people) usually leaves the floor first; it has further to move (Roman, Vorobeyev, Zhekov). (See figure 1)
The switch from driving up to scissoring the legs is not a jump up (which means this lifter has to first come back down to get to where she started) as shown in the video. A weightlifter should ‘tear’ the feet from the floor in the act of scissoring the legs to receive the full effect of the power generated by the legs.
This should be an unconscious ‘tearing’ (‘ripping’), first one foot from the floor to shift the rear leg backwards; followed by ‘tearing’ the other foot to shift the other leg forward. This powerful asynchronous ‘ripping’ the feet from the floor is anything but a jump upward. The one – foot – leaves – the – support – first action of splitting under the barbell is essentially a reaction on the lifter’s part to move the leg to placed backwards first, i.e., it has further to move before it returns to the floor.
The 4th false assumption. Placement of the feet in the fore aft position to a fixed alignment (inside the boxes in video) will automatically secure the lifter’s balance/equilibrium.
/ a predetermined shifting to place feet to boxes drawn on the floor assumes the athlete will be able to balance the barbell overhead with that disposition of feet;
This is another idea that sounds good on paper and even looks authentic on video. Just try doing it after a difficult clean instead of with hands empty. A shifting of the legs to a fixed distance doesn’t teach the athlete to match his/her movements with the requisite power to lift various weights – varying weights should vary in effort.
/ teaching a lifter to shift feet to pre – determined spots in the jerk falsely assumes a pre – determined the effort to move a specific distance is the right amount of effort to lift various weights;
It is common knowledge that the tension of the weightlifter’s muscles varies with lifting of weights of 55, 65, 75, 85, 90%; as does the trajectory of the barbell, speed and inter-muscular coordination (Roman, Vorobeyev, Zhekov, et al). The lifter’s movements vary with different weights; the forces applied to the barbell, its trajectory and the height of lifting all vary. Consequently, the weightlifter has to constantly adjust the effort of lifting appropriate to each weight increment. That is to say the weightlifter has to develop what L.N. Sokolov (1974) called ‘weight sense’; so that one’s movements and forces from the muscles are commensurate with the weight lifted.
The development of ‘weight sense’ is an intricate process because lifting weights in pyramiding increments is complex. The difficulty of performing the skill of the jerk rises with the pyramiding weight of the barbell; especially as the lifter has to perform such a complex skill in the presence fatigue from prolonged straining.
Commensurate effort, in effect, a ‘weight sense’ for varying weights; means among other things, less distance the feet need to move into the scissors position. The heaviest weights need the most effort and typically require a wider scissoring of the legs to both fix and balance the athlete – barbell system.
The 5th false assumption. The lifter accentuates pressing up with “jumping up” to scissors the legs.
Coupling/coordinating pressing up on the barbell in the jerk with driving up with the legs is a mistake which has been advised against since the 1940s (N. I. Luchikin). The arms should push the athlete away from the weight (Luchikin, Zhekov) to accentuate the power of the legs and speed of dropping under the barbell. Not only do proportionally stronger arms and shoulders inhibit the performance of the jerk; pressing with the arms inhibits the full force of the legs; the weaker muscles are situated between a rock and a hard place: between the barbell and the legs. The stronger muscles of the legs end up working against the weaker of the arms and shoulders.
So, it can be said to press up with the arms in the jerk dampens the output from the legs:
“…those who are good pressers try to accentuate the muscles of the arms and shoulder girdle in the thrust phase of the jerk. This causes a sharp reduction of force from the legs, which is the principal reason the weightlifters who are good pressers, perform the jerk poorly.” L.N. Sokolov, 1971
The 6th false assumption. Teaching the athlete to scissors the feet to pre – determined boxes on the floor falsely assumes this arrangement will suffice to balance and fix various weights.
When a weightlifter learns to ‘find’ balance; there is some variance with the distance and alignment of the feet appropriate with varying weights; this gives the athlete greater leeway to ‘stretch’ under the weight in order to fix the barbell overhead within the area of balance. An accommodating width and depth of the entry into the split position enables the weightlifter to adjust to a barbell raised slightly forward and out of position by pushing off the back foot and flexing the right leg to drive the trunk forward and down. (figure 2)
Figure 2. The rear foot of Olympic champion is placed on the platform before the front foot returns. This arrangement enables the lifter to ‘stretch’ the body under the weight to lower body center of mass as well as to adjust the area of balance in the fore aft direction and compensate for a slightly forward barbell trajectory. Charniga photo.
The 7th false assumption. Teaching an athlete mechanical step by step movements to instill the correct habits for moving the body.
/ the coach’s method in the video teaches the weightlifter to switch direction after completing each step: fully straighten the legs, then rise onto toes, push up, jump up to scissors and so forth;
Soviet era sport scientists (Frolov, Levshunov) combined the phases of the “braking” or the phase of slowing down in the half squat for the jerk before switching to straighten the legs into one period. They revealed a weightlifter should not wait until the legs have fully flexed in the half squat before violently straightening the knees.
“the “braking” and the “thrust” phases should be combined into one period so that the athlete is already jerking the bar upward at the beginning of the 3rd phase.” Frolov, V. Levshunov, N., 1978.
In fact, analysis of the elite lifters who performed the jerk with high reliability found that this switching from bending to rising from the half squat was so fast; the best lifters were already straightening the legs as the bar was still bending i.e., the discs were still moving down.
An appropriate name for this idea is to: ‘switch before switching’. However, it needs to be expanded to the following: weightlifters should always be ‘switching before switching’ in either pull or jerking phases of the classic exercises. Always – to – be – switching -before – switching foresees the limitations of the human nerve – muscle system.
Choreographed, step by step motions per the video are too slow and inefficient to lift the biggest weights. The weightlifter’s muscles cannot relax and contract fast enough on commands from the central nervous system if the athlete has learned such a complex exercise with the step – by – step approach. The weightlifter needs to endeavor to be several steps ahead of the next step i.e., to be straightening the legs while still bending.
From what has been discussed of what not to do; it should be obvious the crucial skills are ‘find balance’; develop ‘weight sense’ and always be ‘switching before switching’; skills that involve special methods. The methods depicted in the video are good examples of what not to do.
Integration of the three concepts into the learning and performance of the jerk:
/ the weightlifter has to learn to find and feel balance;
/ commensurate efforts to switch from one action before actually switching (begin to straighten the legs before they have stopped bending);
/ be switching from straightening the legs from the half squat directly to scissoring the legs and so forth.
The coach’s instruction style is unprofessional; fairly common of Chinese techniques. He is an angry, authoritarian; even kicking the woman’s foot repeatedly to make sure it is turned inside the box the way he wants it. Overall the video demos an unproductive nitpicking of each detail; the efficacy of which is highly questionable. Although, some of this behavior is understandable; in the social context of China’s centuries old female problem. All in all, the video represents a good learning experience of what not to do; what not to teach an athlete; how not to proceed to teach weightlifting technique; especially with a female lifter.
A method of learning the jerk:
Learning to manage variance
A reasonable alternative to the method presented in the video integrates and reinforces the specificity of jerking a barbell in competition: ‘find balance’, ‘feel balance’, commensurate effort (‘weight sense’) and ‘switch before switching’. This method is a reverse order of learning sequence.
To implement this method effectively the athlete should have no significant issues with flexibility in elbows, shoulders, knees, hips, ankles, wrists and so forth. If there are issues with mobility they should be addressed first and/or incorporated into the lessons.
Exercises and techniques to learn the jerk in a reverse order sequence.
Key points of emphasis in learning the jerk: – ‘Find’ Balance – ‘Feel’ Balance – ‘Commensurate Effort’ – ‘Switch Before Switching’.
‘Find Balance’:
/ Practice the jerk following a clean as much as possible; even if it is a power clean. This is called specificity; one has to ‘find balance’ after lifting a barbell to the chest in competitions before beginning the exercise; then ‘find balance’ again to fix it on outstretched arms. It is not the same exercise when one takes a barbell from a squat stand or from jerk tables. Specificity is lacking; there are no jerk tables or squat racks on a competition platform.
Individualize Stance:
/ Individualize the kinesthetic sensation of a balanced stance by having the athlete do a vertical jump or a standing long jump. The starting stance for either jump can be a good starting point; either option is dynamic, individually determined; a lot better than chalk lines on floor. Here, the athlete feels how best to use the legs to generate power; arrived at instinctively.
‘Find Balance’ with the Nechepurenko’s (1971) rocking method:
/ Begin without a barbell. Place feet in the start position according to the jumping stance suggested. Have the lifter lean forward until the balance is almost lost. Then rock backwards until almost losing balance backwards. Perform this pendulum movement a few times until the athlete feels balance is centered between the extreme edges of the toes and heels. This is how to find balance in the starting position after standing from the squat.
Figure 3. The rocking method of learning the jerk according to Nechepurenko (1971). The lifter leans forward then backward a few times; in both cases until almost losing balance. The lifter then bends to jerk with balance ‘found’ from pendulum movements; such that the vertical path of the bar is over the feet; far back enough to permit a vertical trajectory as the athlete straightens the legs.
‘Find Balance’/’Feel Balance’:
/ Perform the same Nechepurenko balancing act with an empty bar; or stick first on the shoulders then on the chest as in the actual jerk exercise; the same with eyes closed – first with stick on shoulders, then with stick or empty bar on chest;
‘Find Balance’ {scissoring the legs into the split position}:
/ Scissors legs into split position from starting position with legs straight – without knee bend, arms at sides; then move feet as fast as possible.
/ Scissors legs same as previous, eyes closed; then move feet as fast as possible.
/ Scissors legs same as previous with arms outstretched overhead; then with eyes closed; then move feet as fast as possible.
/ Scissors legs same as previous with stick or empty bar held on outstretched arms overhead; then with eyes closed; then move feet fast as possible.
/ Jerk a stick or empty bar from the chest with legs straight preceded by Nechepurenko rocking to ‘feel balance’ in start then ‘find balance’ in split.
/ Jerk a stick or empty bar from behind the head from straight leg start; then with eyes closed.
Learn to half squat with commensurate effort.
‘Bend to Scissors’
/ as weight is added perform the half squat by unlocking knees to scissors;
Initially, endeavor to jerk from a straight leg start. From straight leg start try to go directly to scissoring. The idea is to develop the sensation of moving to the receiving position to fix the weight overhead; sans the laborious step by step procedure illustrated in the video. The lifter is to be instructed to ‘go to the end’.
As weight is added the method of teaching the half squat:
/ from the start, unlock the knees and scissors. Heavier weights will force ever larger bend in the knees to enable one to reach the end point – in a split position with the weight fixed; start with the weight on the shoulders for this unlock the knees technique; then do the same with the weight on the chest.
References:
/ Charniga, A., “How is it Possible Weightlifters are Stronger”?, www.sportivnypress.com
/ Charniga, A., “Unbalanced Equilibrium in Weightlifting”, www.sportivnypress.com /
/ Charniga, A., “Power, Equilibrium and the Struggle with Horizontal Gravity”, www.sportivnypress.com
/ Bobbert, M., Huijing, P., Van Ingen Schenau, G., “A model of the human triceps surae muscle- tendon complex applied to jumping; ” J. Biomechnaics vol. 19: 11: 887-898:1986
/ Vorobeyev, A.N., Weightlifting, Textbook for the Institute of Sport, FIS, Moscow, 1988, Translated by Andrew Charniga
/ Vorobeyev, A.N., Weightlifting, FIS, Moscow, 1977, Translated by Andrew Charniga
/ Zhekov, I.P., Biomechanics of the weightlifting exercises, FIS, Moscow, 1976. Sportivnypress, Livonia, Michigan
/ Roman, R.A., The Training of the Weightlifter FIS, Moscow, 1968;1974; 1986. English translation (1986 version) Sportivnypress, Livonia, Michigan
/ Ivanov, A.T., “Jerk exercises for athletes of different qualification”, Tiiazhelaya Atletika, 73-78:1971. Translated by Andrew Charniga.
/ Ivanov, A.T., Roman, R.A., “Components of the Jerk from the Chest”, Tiiazhelaya Atletika 1975:23 – 26. Translated by Andrew Charniga.
/ Sokolov, L.N., “Modern Training of Weightlifters” Tiiazhelaya Atletika, 1974:5-7. Translated by Andrew Charniga
/ Nechepurenko, V.A., The “Rocking” Mehtod of the Jerk from the Chest” Tiiazhelaya Atletika Yezhegodnik, 78-80:1971, FiS, Moscow
/ Frolov, V. I., Levshunov, N.P., “The Phasic Structure of The Jerk”, Tiiazhelaya Atletika, 1979:25 – 28. Translated by Andrew Charniga, Jr.
/ Tatishvilli, R.A., “Parameters of the Split Style of the Classic Triathlon Exercises Tyazhelaya Atletika. Sbornik Statei. Fizkultura i Sport, Moscow, Publishers, 1971: 91 – 94, Translated by Andrew Charniga, Jr.