Hi PVstudent
nice preparation and thanks for those definitions. Also thanks for such clear argumentation.
PVstudent wrote:I am not theorizing it is just that the use of carefully defined and used words will simplify the connecting of "experiential and theoretical knowledge". In a sense, since one cannot be privy to what is actually a thought in another person's mind, all written or spoken discourse is theoretical.
before i get into the tech stuff this paragraph is filled with good things but i have to argue, this is theorising and we are theorising. Also whilst true we can't be as privy to another persons thoughts as they are, we can get pretty close. When we share an idea we are getting pretty close. A concept sharing even closer. Sharing an experience closer again, although always differing perspectives of course. Empathy is about discovering what another person is thinking or feeling and i think a coach would do well to have empathy for these things in their athletes.
Back on topic and in agreement with you, some words like
weight and weight can't be compared because they are describing things from a different frame of reference.
Weight is referring to what an object feels like. It is subjective as you said and one persons feel of a particular weight will differ from anothers. Weight is a theoretical objective measurement and can be used for such discussions but not for describing to a 13 year old boy. When i use that word they immediately assume
weight and for this reason i use it. It is a word accessible to all. An example is let your
weight fall with each stride when you run. Or feel the
weight of the pole as it lowers.
It is feeling the
weight of the pole as it lowers that is the key to this way of looking at pole vault. You could call it The Way of the Pole. But i do steal from history.
The pole begins at vertical - weightless; and it ends vertical - weightless, from one end of the runup to landing on the pit. Those jumps we sometimes do - where the pole is left balancing in the box, would be the ideal end of this 'model'. I put the word model in italics because it's not a model but more of a way of looking at the vault. I will explain the view.
Facing the runup from sideways about 50m away watching the pole as the vaulter goes from the runup's first stride to landing in the pit. (landing in the pit is the end of the energy process).
The perfect view of this would be a smoothly rolling pole with no jerks nor accelerated periods breaking it from it's natural rolling action. The rolling action will progressively accelerate until the slowdown as we start to bend the pole with our bodyweight's momentum. During the pole bending phase the cord line takes over as the straight pole line until the pole is straight again.
So what this means is that the plant 'must' begin at a certain point that is determined by the natural rolling of the pole. The timing is determined by the pole.
Any interference with this natural rolling of the pole is taking potential energy away from the vault. Any energy left in the pole at the end of the jump is also lost potential energy. This is why a perfect still and balanced pole at the completion of the jump is the ideal. Never something to focus on, it is the remainer of a perfectly executed jump. Anyway moving on.
I cannot accept your use of the term relative weight as the equivalent of torque induced load because weight is merely a force, or a mass accelerated downward vertically (towards the center of the earth) whereas the torque (due to the weight force) causes the mass to be accelerated in a circular path about an axis. Whilst the two effects may feel the same at any instant for the vaulter they produce entirely different motion consequences. There is nothing theoretical about this need to differentiate between weight / relative weight force and torque because the motion descriptions of the vaulter and the observer of the actions of the vaulter will confuse rotation and linear translation.
I agree with your non-acceptance, i also don't accept but we could get detailed. Anyway as explained above there is the universal idea of weight (heaviness) and the theoretical or scientific meaning of the word weight. Also explained above is the ability for empathy between the observer(coach) and the observed(athlete) and this potential in anyone. But more importantly i don't think there would be any confusion because i don't use biomechanics as a language when i coach. The really interesting bit though is the last part of the last sentence - rotation and linear translation during the plant. How to get this bit correct can be determined by the natural rolling of the pole but this part of it gets tricky for me, however i will have a crack.
As the pole finally pivots over the fulcrum (ie the left hand for most of us) the fulcrum needs to rise and move forward to allow the pole to follow its continuous rolling action. If the pole doesn't move like this it will pivot too quickly. If the left hand doesn't move forward enough as it rises it will cause this pivoting too quickly. If the vaulter does this and is used to the pole pivoting at a speed which is too quick, then naturally they will start the plant later.
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*doesn't work for me
could you reply to this post and add it and Isi's and Bubka's? Please.
In this sequence Lojo suffers from the above ailment. However, even though this plant is late there is still minimal movement from the right hand as he leaves the ground on the 4th last step. From photo one to two the right shoulder has lifted and the right hand has moved from below the hip bone (greater trochanater) to above it. The planting motion has begun.
Looking at when the plant begins mechanically the right hand will rise with the up-momentum provided by the entire body most easily. As in a clean we get the bar moving with the body and then as the body slows the bar continues it's motion upwards. Same with the pole on a smaller scale. So as we leave the ground the pole is coming with us. All we need to do then is allow it to continue to rise as we descend for the next step. This is why more motion appears to occur during the descent into the 3rd last than from the rise off the 4th last.
Anyway moving onto Isi but i use the side on jump. From first photo (4th last step) to second photo (just after mid stride) her right hand moves substantially and the right elbow angle decreases markedly. I see Petrov all over this. For one she is new to Petrov (compared to Bubka) and so she is overemphasising Petrov's bits, such as bringing the right hand all the way up the right side before pivoting at the shoulder. In Bubka his elbow angle doesn't close as much as this would be more correct mechanically than what Isi is doing here.
Ending with the Bubka black and white sequence things get pretty clear. His right hand rises from pic 1 to pic 2 and his left hand lowers. The fulcrum at this point is midway between his two hands or where the pole intersects where his right ASIS is (front top of hip- the bony protuberance). Now i agree his elbow angle hasn't changed much at all and i see this as correct. What is changing moreso is his shoulder position. If you look fairly quickly through pics 1,2 and 3, you can see how his shoulder is rolling back and over. This is what is lifting the pole. It isn't much movement but then at this stage of the plant there isn't much movement. It is after the pole tips over the fulcrum that the right hand has to accelerate a lot.
So all in all from 4th last to 3rd last the pole is still coming to the horizontal, thus the right hand isn't lifting much, it is mainly guiding the pole to the horizontal. The left hand is also lowering to assist the changing angle or rolling of the pole to the horizontal. From 3rd last to 2nd last the pole comes to the horizontal by the time of 2nd last takeoff. During this stage the right hand simply continues the motion initiated upon leaving the ground from the 4th last step. After the horizontal the right hand moves much more quickly of course.
Continuous lowering of the pole and progressive accelerations in run up and takeoff remain to be sorted out. Precisely what is meant by continuous lowering and progressive acceleration in the pole drop (declination) and the run remains to be explored and clarified.
yes they do but hopefully some of the above words have added to their description.
To finish i would like to look at the definition you provided
The functional objective of the "pole plant action" I define as:
The function of the pole plant is to enable the vaulter to arrive at the takeoff with a body configuration and pole orientation angle placement in the planting box that optimizes the transfer of the final momentum and energy of the approach run into a takeoff that can minimize total system energy loss whilst maximizing the potential and kinetic energy imparted to the vaulter pole system at take - off. Efficiency in directing the vaulter - pole system towards achievement of the ultimate goal namely maximum bar height clearance by the vaulter must also be achieved as a consequence of the plant action used.
Nice, so the plant is merely a function enabling maximum bar clearance and not an end in it self. It achieves this specifically by minimising any total system energy losses during the action of putting the pole in the box. You have the result or goal - the bar clearance, the factors involved - body configuration (position?) and pole orientation, and the objective - minimise energy loss during this action, nice! I would prefer less words but i'm a little like Agapit in this way .
cheers
Pete