Power, Equilibrium and the Struggle with Horizontal Gravity

Power, Equilibrium and the Struggle With Horizontal Gravity

Andrew Charniga

Sportivnypress.com

“The majority of weightlifters are usually good at the clean; however, many experience difficulty in jerking the barbell from the chest.” Nechepurenko, V.A., 1971

The most difficult task for the weightlifter is to  jerk the barbell from the chest on the 3rd  attempt in competition. The weightlifter must raise the barbell all the while coping with a rising common center of mass of the athlete – barbell unit until the weight is fixed over head. This is the most difficult skill for the weightlifter to assimilate for those specific conditions of competitions.

To successfully jerk the barbell on the third attempt the weightlifter must cultivate the skill to generate the necessary power to raise the barbell to arms length; while at one and the same time achieve a stable equilibrium. What is so difficult about this?  On the surface jerking the barbell would seem to be a rather simple exercise. 

Conditions defining the complexity of the jerk from the chest on the 3rd attempt:

The lift from the chest is preceded by a fatiguing clean;

The C & J comes at the end of the competition when the lifter is fatigued;

The exercise is performed against a backdrop of heightened psychological tension: the jerk from the chest is final effort of the final motion to decide the final outcome of the competition;

The complexity of the exercise increases with the increasing weight and increasing height of the barbell from the platform, i.e., the final attempt is the heaviest weight the athlete will lift;

The ‘toppling over’ (a horizontal gravitational pull) complicates counterbalancing the barbell;

Figure 1. Most jerks are missed forward. The lifter raises the barbell in curve – linear trajectory far forward enough to prevent him/her from fixing the weight over the base of support. Charniga photo.

Counterbalancing the athlete – barbell system becomes increasingly difficult in the presence of fatigue and heightened psychological tension at the moment of lifting;

Returning the feet in line to complete the exercise exacerbates the problem of equilibrium: the highest general center of mass of the athlete – barbell unit has to be stabilized over a narrow base of support.

Figure 2. Coordinating the expression of equilibrium and power defines the complexity of the jerk. A weightlifter raising in excess of bodyweight,  especially with 200% and more; is subjected to a ‘horizontal gravity’, or toppling force, pulling him/her forward much like sitting on a teeter – totter with someone heavier.
To achieve equilibrium the heavier person has to be shifted closer the fulcrum of the device (figure in upper left). This action is illustrated by the athlete in the figure bending with the vertical projection of the barbell far enough behind the toes to permit a vertical barbell path when the movement is reversed. The figure on the right depicts the narrow corridor within which the barbell’s path must adhere in the half squat and recovery in order to fix it over head. This corridor narrows with increasing weight of the barbell. Charniga photo in middle and from The Training of the Weightlifter, R.A. Roman, 1986.

One can find ample evidence of the extraordinary complexity of the final effort of the final motion. A modest survey of various competitions showed one can anticipate only 30 – 40%  and even fewer, 3rd attempts in the clean and jerk will be successful (table 1). A minimum failure rate of 60% and even higher (jerk misses and clean misses together) is a reasonable tactical consideration for coach and athlete.

Some facts about jerking the barbell associated with third attempt misses in competitions.

1. coordination of strain energy in tendons (especially Achilles) with the elastic recoil of the bar significantly reduce the power of muscular contraction required to lift the weight over head;

2. less power is needed to jerk the weight than to clean it {Kanyevsky, V., };

3. most missed jerks are lost forward (Kanyevsky, V.,);

4. technical problems arise significantly after the barbell reaches 200% of bodyweight, (A.T. Ivanov, 1971); 

5. “lifters in the lighter weight classes have better technique in the jerk, … whereas the heavyweights do not”, A.T. Ivanov, 1971;

6. “.. of greater importance to a successful jerk is the disposition of the barbell, relative to the feet”, (A.T. Ivanov, 1971).

Of the factors listed which characterize the extraordinary complexity of jerking the barbell on the final attempt; solving the psychological problem on the surface, appears to be the simplest solution: cultivate the confidence to jerk whatever weight one can realistically clean. 

The other factors can be divided into two categories: power and equilibrium. The question of power to jerk the barbell need not be an issue; because if the athlete can clean the weight he/she has already expressed more power than is needed to raise it over head (Kanyevsky, 2007). Furthermore, the possibility to sync elastic recoil of the tendons (especially the Achilles) with the elastic properties of the bar, can reduce significantly the requisite power from muscular contraction.  

   

Figure 3. Many coaches and athletes alike, are unaware of the critical role of the calf musculature; especially the Achilles tendons,  to generate power from the the half squat to thrust the barbell overhead. Note bulging calf musculature with feet flat. Charniga photo.  

The power to jerk the barbell is interconnected with the speed of switching directions, the speed of switching from bending to straightening, from yielding to overcoming work. Role of ankle muscles to generate power in the jerk as in the theory of the pull (see Asian pull, www.sportivnypress.com) are at the present time, relegated a subordinate role by coaches and athletes; a big mistake. 

However, that being said, two factors can throw a monkey wrench into the possibility to fully utilize elastic recoil: the inappropriate participation of the arms and excessive fatigue from the clean.  

For instance, various supplementary exercises are employed in training to learn and master technique; designed to develop the power to lift a maximum weight. More often than not, these exercises lessen, or even worsen assimilation of the actual skill of the classic jerk. Frequently, the logic behind a supplementary exercise is based on analysis of segments of the classic jerk; not infrequently, the athlete will practice a motor pattern which contradicts the actual motor skill necessary to correctly perform the exercise as a whole. 

Assimilation of the optimum skill to jerk the very heavy weights from the chest over the long term encapsulates a diametric complexity:

1/ an excessive use of supplementary exercises to perfect jerk technique based on analysis of the exercise as a series of individual interconnected parts and not on the movement as an integrated whole;

The correct technical execution of the weightlifting exercises usually contradicts analysis of each part of the movement separately.” A.N. Vorobeyev, 1988

2/ the correct technique one must learn to jerk maximum weights (beginning with but not exclusively 200% of body weight) can be neglected with beginners and novices because they usually jerk successfully; since weights are less than or not much more than bodyweight. This circumstance fosters a false sense of security their technique is fine (A.T. Ivanov, 1976).

The Mistake of Practicing Power and Neglecting Equilibrium

The practice of integrating a host of supplementary exercises which involve motor patterns essentially different from the classic jerk is all too common. Neglecting the precise skill to lift more 200% of bodyweight in the classic jerk, from the very beginning of weightlifting lessons, is the underlying cause for the commonplace 60 – 70% competition failure rate in the jerk on the 3rd attempt.   

For instance, the half – jerk is a common supplementary exercise where one performs a half squat and recovers to fully extended legs and a rise onto the toes. On the surface it seems like a good exercise. However, a weightlifter should already be pushing away from the barbell while the knees are still flexed; even with a slight rise onto the toes (Zhekov, 1976).

The negative effect of interference from incorrect motor habits like a full extension in the half jerk; becomes manifest when a lifter fails to jerk a heavy weight in competition; especially under the psychological pressure characteristic of 3rd attempt. Making matters worse, the coach may tell the athlete to drive up harder; assuming the missed lift was due to insufficient vertical force.  

The data presented in table 1 shows the success rate for the 3rd attempt clean and jerk is rather dismal; ranging from a low of 23% to a rare high of 46%. Consequently, it is reasonable for a coach or athlete, in the midst of the heat of competition, to assume that at least 60% of the 3rd attempt jerk weights selected will be failures; it is even a fair bet to assume as many as 70% will fail. Consequently, on occasion a very conservative selection of weights of 2 or even a 1 kg increment with a high degree of certainty of success will be in order; because, 1 or 2 kg added to the total is a lot better than 0 after the athlete misses a 4 – 5 kg increment.

Table 1. Success rate of snatch and clean and jerk at various national and international competitions. {data compiled by Clancy Benton and Andrew Charniga}

Yr/event   Snatch     Jerk  
  1st 2nd 3rd 1st 2nd 3rd
2017USN/F 68% 50% 47% 72% 60% 31%
2017USN/M 62% 43% 33% 73% 44% 23%
2017EWC/F 84% 66% 57% 88% 65% 41%
2017EWC/M 75% 62% 44% 81% 55% 37%
2015WWC/F 76% 62% 45% 85% 57% 37%
2015WWC/M 77% 52% 45% 76% 56% 37%
2016OG/F           40%
2016OG/M           30%
2018USN/F           37%
2018USN/M           30%
2019USN/F           30%
2019USN/M           30%
2019AWC/F           31.5%
2019AWC/M           36%
2019EWC/F           41%
2019WC/M           46%

Abbreviations: USN – USA national Chps.; EWC – European chps.; OG – Olympic Games; WWC – World (senior) weightlifting chps.; AWC – Asian weightlifting chps.; M – male; F – female.

Another common practice is to increase muscle mass in the upper extremities to develop jerking power. This is not a good idea: 1/ increased mass in upper extremities raises body center of mass; 2/ increases likelihood arms will be more active; especially to press up on the barbell; 3/ wasted mass for athletes in the light categories, i.e., less relative mass in lower extremities to be able to weigh within weight class limits.

A precise interconnection between strength and/or contribution of the arms relative to the legs in jerking a barbell has not been established. However, Sokolov (1965; 1974) established a negative connection between the strength of the upper extremities and the jerk, i.e., lifters who were good pressers tended to have difficulty jerking the barbell. Therefore, something else to bear in mind in today’s biathlon era is the effect relative strength and accompanying muscle mass of the upper extremities exerts on a weightlifter’s performance in general; and, the jerk from the chest in particular.

Sokolov (1974) indicated a ratio of around 40 – 41% upper extremity strength to lower extremity strength should be considered optimal so that the strength of the arms and shoulder girdle do not hinder performance of the jerk. Assuming those figures are a  reasonable point of reference, the question of how much muscle mass that translates into is not specified.  

From what has been presented effective use of the leg springs and speed of movement will provide ample power to raise the barbell. Keeping the vertical projection of the barbell over the feet in the starting position and during the descent into the half squat and recovery address the critical factor of equilibrium for the ‘thrust’ phase of the jerk. The fact that most missed jerks are lost forward is indicative the vertical projection of the bar in the starting position and or during the half squat results in a forward barbell trajectory. Consequently, more often than not the lifter will lose the lift in front. 

 Practical recommendations to increase chances of success of the 3rd attempt jerk

/ learn the starting position with the “rocking” method of Nechepurenko;

/ warm up in competition jerking an empty bar and light weights with the eyes closed;

/ perform multiple sets with an empty bar without half squat, accentuating moving the feet  and pushing the body down, not the barbell up;

/ perform only the classic jerk with scissoring for all warm ups;

/ accentuate moving the body (scissoring the legs) in the jerk especially with an empty bar and very light weights.

/ re – trace the learning sequence of movements and exercises to find the correct technique if the athlete begins experiencing problems jerking.  

 

References

1/ Charniga, A., “Scaling of body mass in weightlifting”, 2018, www.sportivnypress.com

2/ Vorobeyev, A.N., Weightlifting 1988

3/ Ivanov, A.T., “Jerk exercises for athletes of different qualification”, Tiiazhelaya Atletika, 73-78:1971. Translated by Andrew Charniga.

4/ Sokolov, L.N., “Modern Training of Weightlifters” Tiiazhelaya Atletika, 1974:5-7. Translated by Andrew Charniga

5/ Nechepurenko, V.A., The “Rocking” Mehtod of the Jerk from the Chest” Tiazhelaya Atletika Yezhegodnik, 78-80:1971, FiS, Moscow