The Continuous Chain Model in the Pole Vault by Roman Botcharnikov INTRODUCTIONThe core of the continuous chain theory in the pole vault is the continuous input of energy by a vaulter into the vaulter-pole system during the event.
Time periods in the event when the vaulter increases the level of energy in the vaulter-pole system are "active" phases. Periods when the vaulter does not increase the level of energy in the system are "passive" phases.
At the world record level the energy in the system is the most important factor that defines the height that the vaulter can clear. Therefore, the higher the energy, the higher the potential height the vaulter can clear. The vaulter should maximize the input of energy when he performs the event.
Time is energy in the pole vault. In analogy with a car engine a vaulter's body has defined power (force per time unit) at any given time of the vaulter's career. In other words, any vaulter's body can produce a finite amount of energy per given time unit, let's say per second. Therefore, any time that a vaulter does not input energy into the vaulter-pole system is lost time and leads to lesser input during the event. (In our terms this lost time is defined as the sum of passive phases in the event.)
GOALIn the ideal case, using the continuous input of energy concept, we eliminate or substitute all "passive" phases during the event and identify the event as one continuous chain of "active" phases. We recognize that passive phases in the event occur due to the impossibility of a vaulter performing ideally and, because of this, there may be passive phases used in the event to redistribute energy in order to complete the event.
As a consequence, a vaulter should not train to use passive phases, but should instead try to eliminate them. some passive phases in the event can be simply substituted for by active phases; other passive phases can be eliminated by increasing input of energy in the active phases. In the actual performance, passive phases can not be completely eliminated, but they can be minimized.
Returning to the analogy with a car, if one drives a car with manual transmission, passive phases occur during periods of the gear shifting, and in order to improve performance one should minimize these passive phases, trying to eliminate them.
PASSIVE PHASESSome of the common passive phases are: chest penetration, pushing the pole by the left arm, and waiting for the pole to recoil. These actions do not increase the input of energy into the vaulter-pole system.
ENERGY SOURCEOnly a vaulter can put energy into the vaulter-pole system. The pole vault is significantly different from other jumping events in track & field. A pole vaulter can input energy constantly until the release of the pole, to improve the result.
There are two major groups of muscles of the vaulter's body that put energy into the system. the first group we can code as a "leg group." This includes all muscles that participate in the run-up/jump phase of the event. The second group we code as an "arm group." This group includes all muscles used in the planting of the pole and the "off-the-ground" phase of the event.
Here are the phases and groups of muscles that input energy into the vaulter-pole system:
1. Leg group in the run-up/jump phase.
2. Arm group in the "plant action."
3. Arm group in the "rock-back"(inversion) phase.
4. Arm group in the "pull-push" phase.
Only input of these groups of muscles contribute to the final energy of the vaulter-pole system; there is no other factor, except maybe a tail wind, that positively contributes to the level of energy.
The best technique for the event will concentrate on the increase of inputs by these muscle groups over the duration of the event, while minimizing energy losses that can occur in the friction losses.
RUN-UP CONTINUOUS INPUTA simple lapse in the run-up, such as looking to the side, will diminish the athlete's speed noticeably. When a vaulter has a mid-mark in his run-up and he is paying attention to the mark with the purpose of checking the accuracy of the run-up, he interrupts the energy input some time before and after the mark.
In other words, the vaulter in the best-case scenario keeps the same level of energy for two or three strides at the most important time in the run-up phase. All this checking is done to have control in the run-up to avoid being "under" in the takeoff.
In his early career, Sergei Bubka and his coach Vitaly Petrov did not use a mid-mark, but now Bubka does use one and we can see that the percentage of the jumps in which Bubka is "under" at the takeoff has not decreased. There is a different explanation of being "under" than just an inconsistent run-up, but it is not in the scope of this article.
According to the continuous chain model, checking the mid-mark during the run-up by the athlete breaks continuous energy inflow and should be eliminated. This lapse not only breaks energy inflow, but also distracts the concentration of the vaulter from the actions he is about to perform in 6-8 strides, a most critical phase of the event. The vaulter and coach should find different, less distracting methods for the athlete to monitor his run-up and maybe use the mid-mark for the coach's checking only.
The angle of takeoff of the center of gravity of the vaulter's body is an individual one for each vaulter. There is one certain thing about this angle- the takeoff angle relative to the ground should be as large as possible.
In other words, the vaulter should not overload the pole in the takeoff if he can avoid it. Overloading the pole puts more energy into the pole and increases the loss of energy in pole friction because a pole never gives back 100% of energy.
There is another reason against a horizontal or low-angle takeoff. The vaulter using a horizontal takeoff will have a longer hang on the pole. This is a passive phase that does not contribute energy into the system.
There have not been any scientific experiments that define that exact formula of the takeoff angle, but practice shows that with a horizontal takeoff, the vaulter loses balance in the second part of the vault as well as loses energy into the system in the second part of the vault. This is because the time lost on pushing the pole trying to delay rock-back means the vaulter has less total energy than if he had jumped more vertically and did not have to spend extra time for the pole penetration.
The vaulter should not receive any resistance from the pole while on the ground; otherwise he will resist using his leg, back, shoulder, etc. muscles and lose energy in muscle friction and increase the chance of injury.
Ideally the vaulter should complete his jump off the ground before the pole bends, as Bubka did in his first 6 meter jump. In this jump, pole resistance was eliminated while the vaulter was on the ground. This will eventually produce the jump before the pole bends.
PLANT INPUTOriginally the plant phase had one main purpose in the event: to prepare the pole for the most efficient energy transfer from the "run-up/jump" phase into the vault. Besides this preparation, the vaulter should not overlook the importance of the plant phase as an additional input of energy into the vaulter-pole system.
The moving mass during the plant phase is equal to the sum of masses the pole and both arms of the vaulter, which can add up to at least 15-20kg (33-44 lbs.).
From the energy point of view, the arm action in the plant phase should be similar to the arm action in any jump. From an energy point of view, the arms' vertical movement, relative to the vaulter's body, should continue through takeoff and end after the vaulter is off the ground. In other words, if the right arm stops moving up relative to the vaulter's body when the vaulter is still completing his jump off the ground, his takeoff leg will receive an additional 15-20kg (33-44 lbs.).
INVERSION INPUT (TIMING)The vaulter should begin the rockback (inversion) immediately after completion of the jump and post-jump leg extension. The quality of post-jump leg extension should only depend on quality and completion of the jump. In other words, the vaulter, in an ideal performance of the event, should not delay the rock-back by these actions.
Means by which vaulters delay rock-back is via the action of the left arm, blocking against the pole in the takeoff phase and by further chest penetration. These actions divert the body from its natural swing and redistribute the natural swing energy from the mass lifting action into the pole bend.
The blocking left arm or the chest penetration are not contributing any additional energy to the vaulter-pole system. These actions only redistribute energy that is created in the run-up The vaulter should keep his body as straight as possible during inversion (rock-back) phase. This will keep the center of mass lower for a longer time, which will contribute to the pole penetration.
INVERSION INPUT (CONTINUATION)The pull-push phase in the event is almost identical to the similar phase in the vault with a rigid pole. In vaulting with a rigid pole the vaulter will not wait for the pole to recoil, but he will continue his actions on the pole without delay from the beginning of the inversion phase until he is off the pole.
There is no reason why the vaulter cannot perform in the same way on the fiberglass pole. Delay with the pull-push action and waiting for the pole to recoil brakes the energy flow input into the system; so, according to the continuous chain model, the waiting phase should be eliminated.
MODEL AS A STIMULATORThe training system in which a vaulter improves the active phases of the event will stimulate the vaulter to concentrate and improve muscle strength and the positions of the body in the active phases of the event. This is the first thing the vaulter should improve in order to achieve a high result. Passive phases happen as a result of mistakes and unfavorable conditions and the body makes automatic adjustments in order to successfully complete the event.
One cannot predict how deep the chest penetration will be or how strong the push of the pole with the bottom arm in a particular performance, but in the best performances, one certainly will penetrate with the chest less and/or push the pole less with the bottom arm.
"UNDER"The vaulter who is "under" will usually compensate for energy lost in the takeoff by pushing the pole with the left arm during the off-the-ground phase and penetrate further with his chest. Both actions delay the beginning of the rock-back, which helps with pole penetration, but these actions will also prevent the vaulter from inputting the energy into the system at that time and considerably lowers the effectiveness of the rock-back and pull-push phases of the vault. So, the vaulter's actions enable him to complete the event, but with a considerable reduction in total energy which limits the height the vaulter can clear.
"OVERGRIPPING"A similar situation occurs when the vaulter uses a higher than necessary grip on the pole in a competition.
The vaulter redistributes more energy into the pole. This energy was created during earlier phases of the vault. The vaulter puts himself in a disadvantageous position for further action on the pole as well as losing time and possible energy input; therefore he ends up with lower total energy at the end of the vault.
The higher the grip on the pole the longer the left arm push and chest penetration is. In this case, the more time lost and the less energy put into the system, the less total energy the vaulter's body has at the end, and the lower the height the vaulter will clear. That's why when the vaulter raises the grip unrealistically for particular conditions, he will jump lower than with a lower grip. Therefore, in competition a vaulter should use his experience and best judgment when choosing his grip in order to maximize the result.
Sometimes lowering the grip two inches can improve the push off the pole by six inches. With the lower grip a vaulter can minimize passive phases because he does not need to worry that much about penetration into the pit. By minimizing the time spent on passive phases the vaulter has more time left to increase energy input into the system (more energetic actions on the pole) and, therefore, to increase his push from the pole.
ON COMPENSATING These examples are very simplified, but they correctly describe causes and effects in vaulting. In the cases described above the vaulter is forced to compensate for his mistakes (being under or having an excessive grip). Some vaulters will deliberately perform these compensatory actions on any grip and with the correct takeoff, just because they think that these actions benefit them. These vaulters end up with many unnecessary energy losses and as a consequence have a lower bar clearance.
THE BIGGER BENEFIT OF THE MODELThis article was written to create an understanding of the event as continuous energy input and that this concept is a way of constant stimulation of improvement of physical input by a vaulter. The concept is so simple that it can be taught easily and create in an athlete's mind a definite correlation between physical input and his result. Furthermore, it can create a drive for personal energy input increase instead of improvement in the usage of the pole.
DESCRIPTION OF IDEAL CONTINUOUS ENERGY INPUT IN THE VAULT• Concentrate on the event as a whole.
• Begin the run-up with calm consistent strides, building up the cadence and the stride length toward the takeoff point. (Increase efforts toward the pole release).
• Begin lowering the pole approximately four lefts before the takeoff point, while increasing the cadence of the run. (From this moment on, the arms move continuously.)
• In the last two strides create additional vertical momentum of the arms with pole that will continue through and after takeoff from the ground (towards the bar).
• Explode! Jump off the ground vertically towards the bar, completing fully the takeoff leg cycle with complete vertical stretch of the body as a result of the jump. Do not block with the bottom arm to the pole.
• Invert (rock-back) immediately after completing the jump off the ground.
• Continue to invert as on the gymnastic rings into the handstand, catching up with the pull-push action and accelerating to the moment of the pole release.
• Use appropriate movements to avoid the bar and to land into the soft pit.
Note: Do not confuse "ideal continuous energy input" with perfect technique. Perfect technique is different for every jump, but the idea of continuous input stays the same all the time.
It is possible to perform almost exactly as described above, using a grip on the pole that bends only slightly. For a 5.80m (19' 1/4") vaulter it would be possible to perform this using a grip of 4.40-4.50m (14'5"-14'9"). Then, as the vaulter increases his grip, he will automatically have longer and longer passive phases such as chest penetration or pole pushing with the bottom arm.
The key here is trying to minimize passive phases as the grip rises by increasing energy input and directing the energy flow (speed vector) correctly, towards the bar. The same approach is true for any grip from 4.50 to 5.30m (14'9"-17'4"). At some point overgripping occurs. The problem with overgripping is that passive phases become so large that a vaulter cannot increase them anymore to ensure penetration and he loses all the time available to him to create a quality inversion (rock-back). As a result, there is a point where a vaulter is just penetrating enough to complete the event, but is unable to create a quality inversion, so the only significant energy input achieved was run-up and jump. Little energy is left for the "off-the-ground" phase. As a result of overgripping, the total amount of energy of the vaulter-pole system will be smaller, so only lesser heights can be cleared.
How to fight overgripping?
1. Improve plant action. That will save energy. (A correct plant leads to a resistance-free takeoff).
2. Decrease time spent in passive phases by increasing input in active phases.
3. Minimize passive phases.
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