Run Discussion
- altius
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Sorry - cant leave it at that. 1. Go back through my posts and point out where I EVER said that the majority of a vaulters impulse comes from the clawing action. 2. Go back through my posts and point out where I ever said that speed was NOT important on the runway. You guys are good at the red herrings - you use them all the time to divert folk from what you originally said - go back and read your own posts and you will see what I mean.
But dtrack28 - let me know when your book comes out - I will certainly buy a copy. Thanks for the advice on taking a break - I hope that after you have spent forty years coaching the vault, youngsters are as polite to you.
But dtrack28 - let me know when your book comes out - I will certainly buy a copy. Thanks for the advice on taking a break - I hope that after you have spent forty years coaching the vault, youngsters are as polite to you.
Its what you learn after you know it all that counts. John Wooden
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Once again we go back to the point are you referring to the drive phase the first few steps or as you reach top end speed.
During drive or acceleration it is about power because you have to overcome inertia by performing more or a driving action.
ONce you near top end speed it is about conserving energy. There is no driving motion. It is a clawing or pawing action in an attempt to tap your foot on the ground. The less time you speed on the ground with proper cyclical action the faster the speed you can acheive and the longer you can hold such speeds.
Since this is the information our Elite Development Coaches are teaching. I would assume they are on to something, but then again i guess the past 100 years of studying the way people run was worthless.
TO attempt to drive later and step behind your COM will cause a forward lean and you to stumble.
Do the experiment. Grab a 16 foot pole. Get up to speed with lets say 8 total steps. Than start purposely trying to step behind you as the pole tip is lowered. Let me know if if you can support the weight and not slow down.
You are looking at a sprinter with no extenal objects int heir hands and a vaulter.
You must look at the vaulter and pole system. YOU COM is not under your hips. It is slightly in front of your hips during the middle of your approach as you reach top end speed.
PS. man now another quality coach is not going to post. Well back to a boring forum again.
During drive or acceleration it is about power because you have to overcome inertia by performing more or a driving action.
ONce you near top end speed it is about conserving energy. There is no driving motion. It is a clawing or pawing action in an attempt to tap your foot on the ground. The less time you speed on the ground with proper cyclical action the faster the speed you can acheive and the longer you can hold such speeds.
Since this is the information our Elite Development Coaches are teaching. I would assume they are on to something, but then again i guess the past 100 years of studying the way people run was worthless.
TO attempt to drive later and step behind your COM will cause a forward lean and you to stumble.
Do the experiment. Grab a 16 foot pole. Get up to speed with lets say 8 total steps. Than start purposely trying to step behind you as the pole tip is lowered. Let me know if if you can support the weight and not slow down.
You are looking at a sprinter with no extenal objects int heir hands and a vaulter.
You must look at the vaulter and pole system. YOU COM is not under your hips. It is slightly in front of your hips during the middle of your approach as you reach top end speed.
PS. man now another quality coach is not going to post. Well back to a boring forum again.
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dtrack28 wrote:You are right the guy running faster spends less time on the ground. But look at where his foot is striking compared to his center of mass. His foot strike is almost directly underneath his body which accounts for the less time spent on the ground. The slower runner strikes further in front of his body, causing him to "break" (like in a car kind of break), which slows him down and doesn't allow him to push off the ground as efficiently. Here's where it gets interesting...with your foot striking closer to your center of mass and trying to lessen time on the ground like you suggest (an idea that I think I'm begining to like)...YOU DON"T HAVE THE FOOT/LEG POSITION OR THE TIME TO "CLAW" at the ground as your main source of force. "Clawing" would essentially keep your foot on the ground longer as you put it on the ground in order to pull to generate force. Unless I'm missing something, the combination of what I'm saying (focus on pushing off of the ground to generate the most force) and what you are saying (lessen the time your foot is in contact with the ground) almost support each other and there isn't much to argue about. By putting your fot down closer to your center of mass you not only force yourself to rely off of pushing off of the ground rather than clawing, but you also shorten the amount of time your foot is in contact with the ground. Sounds reasonable to me.
Ok I don't think you get what we mean by clawing/pawing action. Maybe i should say tapping. It should be a quick clawing action like a cat caws at something. Quick clawing motion. On the other hand a raking action where by you grap the ground and drag through is not what we are referring to. This would mean you purposely step down way in front of your COM and pull yourself through. This is in by no means what I or I think Altius is referring to. This is the action that causes hamstring proplems.
dtrack28 wrote:ok, first the romanian deadlift isn't a true deadlift! Also called the straight legged deadlift, its main focus is the glute, hams, and lower back as you said. This is a completely different lift than what I have been talking about this entire time. Second, this lift really doesn't stimulate all of the same muscles used when a vaulter moves from the end of the rockback to becoming inverted. When inverting you are fighting the force of gravity, your hams have little to do with it. It is mostly lower back, hips, and glutes.
Hopefully somebody will find a way to put what I and ADTF Academy said into one super theory, because I think some good ideas are being thrown around here.
The romanian deadlift as far as I knew was the origninal deadlift. I think the deadlift your talking about is used to set up the Jerk and Clean. THese are both excellent lifts and idea for speed development. By the way I dont' know how you jump or what you coach but I beleive in a straight trail leg to inversion not a tuck and shoot. HMMM Straight Leg Deadlift Straight leg trail leg. Every athlete that wants to increase speed and power should perform the Olympic lifts over supplemental lifts ie Bench Press. The set up to the Clean and Jerk are exactly what your talking about and do use the quad as well with the ham and glute.
As far as not simulating the same muscles I will agree partly. I think what it does do is teach the concept of keep the hands tight to the body and remaining in a solid position. If you allow your back to arch (which should never happen) then you fall off the pole or you can't lift as much weight. The hips should be fired into the bar almost as if you have a slight backwards lean finish when you perform the lift. Similiar to that of the BUBKA motion. Yes this should not take the place of actually BUBKAS. But if you want the ability to overcome the force the pole is applying on your hands during move to inversion you need to be able to deadlift a decent amount. Or be very proficient in the Clean and Jerk which use a similiar deadlift motion to move the weight.
dtrack28 wrote:I have one more question...if speed is not an important part of the vault, doesn't it seem funny that the fastest guy on the runway has the world record?
LOL watch the vault at Athens on Stabouchsprung on the very bottom of the list. Your telling me that Bubka is not doing what Altius is saying. You can't watch the last step shown but the 3 step out. It plants slightly in front of his body, but right under the Vaulter and Pole Systems COM.
Also if you watch his stride does he push all the way through as you suggest so that he has a straight leg behind him before he starts the recovery of his heel. Or does it paw the ground and then actively drive back up to his glute before he drives all the way behind him.
HMMM I think you answered your own question with Altius was right.
- Carolina21
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ADTF, Altius and DTrack,
If anyone cares to read this I think I can answer some of the problems and concerns and help to reach an agreement at least I would like to try.
ADTF Wrote:
Ok so here we get a better idea of what you are referring to as clawing. But it still seems to me like you are referring to a pull on the ground (you’re actually not but I see where it is getting misinterpreted because a pull is what I imagine). I think possibly a better description would help, claw seems to cause confusion as to the true intention.
The important and key problem people are missing or failing to point out clearly is a vaulters COM is in front of his/her hips. So his/her ideal foot strike would be directly in line with his COM to maximize speed therefore producing a foot stike in front of his/her hips.
About a year ago, I went to a biomechanics presentation by Dr. Mann, you may or may not know him. Let me preface this by saying this is a much dumbed down and abbreviated summary of what I learned. Anyways what I got out of his presentation was that ideally, again ideally, and this is referring to Sprinting, not directly to vaulting, but I make the correlation later. When anyone runs their foot does strike in front of their COM and for a split second their skeletal structure in their legs absorbs the force as their muscles regroup to push off the ground, he called it a vault of the leg because your bones act like a vaulting pole (pretty cool). In his numerous studies the sprinters who could minimize this vault and use more muscle to create force could regroup quicker, spend less time on the ground, and ran faster and more efficiently…. just as everyone on here seems to agree less time on the ground is better. Therefore, in an ideal situation your foot would indeed strike directly beneath your COM and only your muscular system would be involved and only apply a force forward and up and in a sense instantly happen this would equate to nearly zero ground time. This should be what we are going for, most efficient and least time on ground? The reason we as sprinters all must strike our foot in front is because no one has strong enough muscles in their legs to absord and impulse the necessary force to allow this to happen, we all HAVE to rely on our skeletal structure to some extent to run, and the faster more efficient runner relies on it less. Dr. Mann has done much work with Allen Johnson who trains here at USC and the reason Allen has been so successful in the hurdles is for this very reason, as he comes off the hurdle he is able to strike his foot nearly directly below his COM and therefore spends less time on the ground and his energy is directed forward down the track and can get to the next hurdle faster than any one in the world. Allen is able to exert a huge impulse that allows minimal use of his skeletal structure and mainly comes from his muscles. So I ask again shouldn’t we be trying to do this ourselves in the vault to maximize our speed? Yes, at least that what I will do.
Now to the Vault:
The foot strike in the vault will be in front of the hips unlike a sprinter because our COM is in front of our hips unlike a sprinter. But the same principals apply, the less you rely on your skeletal system in sprinting the faster you can run because you spend less time on the ground.
Therefore, since the pole forces our COM’s forward the vaulter will appear to strike his foot in front of his body but this would actually be very close to the vaulter and pole systems COM in an ideal situation. The pole forces vaulters into this position. If we could measure Bubka’s exact COM and see where his foot strikes in relation to that COM, I would be willing to bet his foot strikes closer to his COM than any other vaulter has to date. This is why he consistenly could run near or at 10.0 M/S. Bubka had enough athleticism and pure power to allow for this foot strike. If Bubka had perfect power he would actually maximize his speed by a foot strike directly in line with his and the poles COM.
So I think it is wrong to say that we should try or intend to strike our foot in front of our COM. The COM is sitting in front of the vaulter and an ideal foot strike would be inline with the vaulter and poles COM.
Whewwww.
If anyone cares to read this I think I can answer some of the problems and concerns and help to reach an agreement at least I would like to try.
ADTF Wrote:
Ok I don't think you get what we mean by clawing/pawing action. Maybe i should say tapping. It should be a quick clawing action like a cat caws at something. Quick clawing motion. On the other hand a raking action where by you grap the ground and drag through is not what we are referring to. This would mean you purposely step down way in front of your COM and pull yourself through. This is in by no means what I or I think Altius is referring to. This is the action that causes hamstring problems.
Ok so here we get a better idea of what you are referring to as clawing. But it still seems to me like you are referring to a pull on the ground (you’re actually not but I see where it is getting misinterpreted because a pull is what I imagine). I think possibly a better description would help, claw seems to cause confusion as to the true intention.
The important and key problem people are missing or failing to point out clearly is a vaulters COM is in front of his/her hips. So his/her ideal foot strike would be directly in line with his COM to maximize speed therefore producing a foot stike in front of his/her hips.
About a year ago, I went to a biomechanics presentation by Dr. Mann, you may or may not know him. Let me preface this by saying this is a much dumbed down and abbreviated summary of what I learned. Anyways what I got out of his presentation was that ideally, again ideally, and this is referring to Sprinting, not directly to vaulting, but I make the correlation later. When anyone runs their foot does strike in front of their COM and for a split second their skeletal structure in their legs absorbs the force as their muscles regroup to push off the ground, he called it a vault of the leg because your bones act like a vaulting pole (pretty cool). In his numerous studies the sprinters who could minimize this vault and use more muscle to create force could regroup quicker, spend less time on the ground, and ran faster and more efficiently…. just as everyone on here seems to agree less time on the ground is better. Therefore, in an ideal situation your foot would indeed strike directly beneath your COM and only your muscular system would be involved and only apply a force forward and up and in a sense instantly happen this would equate to nearly zero ground time. This should be what we are going for, most efficient and least time on ground? The reason we as sprinters all must strike our foot in front is because no one has strong enough muscles in their legs to absord and impulse the necessary force to allow this to happen, we all HAVE to rely on our skeletal structure to some extent to run, and the faster more efficient runner relies on it less. Dr. Mann has done much work with Allen Johnson who trains here at USC and the reason Allen has been so successful in the hurdles is for this very reason, as he comes off the hurdle he is able to strike his foot nearly directly below his COM and therefore spends less time on the ground and his energy is directed forward down the track and can get to the next hurdle faster than any one in the world. Allen is able to exert a huge impulse that allows minimal use of his skeletal structure and mainly comes from his muscles. So I ask again shouldn’t we be trying to do this ourselves in the vault to maximize our speed? Yes, at least that what I will do.
Now to the Vault:
The foot strike in the vault will be in front of the hips unlike a sprinter because our COM is in front of our hips unlike a sprinter. But the same principals apply, the less you rely on your skeletal system in sprinting the faster you can run because you spend less time on the ground.
Therefore, since the pole forces our COM’s forward the vaulter will appear to strike his foot in front of his body but this would actually be very close to the vaulter and pole systems COM in an ideal situation. The pole forces vaulters into this position. If we could measure Bubka’s exact COM and see where his foot strikes in relation to that COM, I would be willing to bet his foot strikes closer to his COM than any other vaulter has to date. This is why he consistenly could run near or at 10.0 M/S. Bubka had enough athleticism and pure power to allow for this foot strike. If Bubka had perfect power he would actually maximize his speed by a foot strike directly in line with his and the poles COM.
So I think it is wrong to say that we should try or intend to strike our foot in front of our COM. The COM is sitting in front of the vaulter and an ideal foot strike would be inline with the vaulter and poles COM.
Whewwww.
-Rise to the occasion
PR: 18' 4.0
PR: 18' 4.0
During drive or acceleration it is about power because you have to overcome inertia by performing more or a driving action.
ONce you near top end speed it is about conserving energy. There is no driving motion. It is a clawing or pawing action in an attempt to tap your foot on the ground. The less time you speed on the ground with proper cyclical action the faster the speed you can acheive and the longer you can hold such speeds.
Ok, tried to combine our thoughts to make something that made sense but you are too stubborn to go for it so I'll keep on arguing with you. What don't you get about the term "constant running?" The only thing I have argued is that during constant running (basically any running motion) your power comes from pushing off the ground once your foot is beneath your body and before you cycle back up to your butt. I now understand what you meant by tapping/clawing and it was a little different than what I was saying. But now that I understand it I've started thinking...
if the goal of tapping is to maintain speed once you are at your max, doesn't that mean that each stride much exert as much force as possible? And if tapping (a relatively passive action) doesn't put as much force into the ground as your last stride it took to get to that top speed, then wouldn't your speed steadily decline? Finally who "conserves" energy in a 100, 200, long jump, etc? These are events in which oxygen deprevation during the race/jump wont have much of an effect on your performace as you're body will have enough energy (ATP) so that your body does not begin the production of lactic acid. But then again maybe I don't understand what you mean by "conserve" energy either.
I agree with caroline, we all put our foot down in front of us. But the goal is to get it down as close to our center of mass as possible. I also now agree that spending as little time on the ground is important in imporving speed. But I still believe that in order to do this and still maintain max speed you must apply maximum force in the vertical direction, making real deadlifts (Romanian deadlifts aren't deadlifts) coupled with plyos more important than squats in the weight room.
And for altius...here is a post you made awhile ago.
Is this fact important - of course. It means that vaulters should include long jumping in their training before they focus on trying to improve their 100 times. Since there is an even tighter correlation between LJ and sprinting speed - there should be a pay off both ways.
I agree completely, 100m speed is important to vaulting high, the long jump is more important. My concept with the sprint is the same. More power is put into the pushing part not the clawing, so working on the push (via deadlifts and plyos) is more important than the tap. Both exist and are important to running mechanics but one has a higher correlation with any type of speed (top speed, or accelerating), so that is the one you should focus on in order to increase your maximum controlable speed on the runway. The way I'm looking at this is the same way you looked at the 100m and long jump. I didn't come on the board and start mentioning that bubka was faster than everyone else (only did that in this board to dish back some smart a** comments after you did the same) which is the real reason he jumped higher. All of the photos I put up were just to illustrate the importance of pushing off of the ground. Looking back I realize that the dragilla one was bad in context with the discussion. You were right about egos getting in the way which is why inevitably you will respond one last time...guess its hard once you've written a full of ideas you took from someone else to listen to an 18 year old that may or may not have something right.
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dtrack28 wrote:if the goal of tapping is to maintain speed once you are at your max, doesn't that mean that each stride much exert as much force as possible? And if tapping (a relatively passive action) doesn't put as much force into the ground as your last stride it took to get to that top speed, then wouldn't your speed steadily decline? Finally who "conserves" energy in a 100, 200, long jump, etc? These are events in which oxygen deprevation during the race/jump wont have much of an effect on your performace as you're body will have enough energy (ATP) so that your body does not begin the production of lactic acid. But then again maybe I don't understand what you mean by "conserve" energy either.
Your still missing the point. An impulse determines your speed. Created by a large force over a large period of time. During Accleration. Or by a small force over a short period of time. Top end Speed.
The tapping of the foot is based on the later top end speed. The driving of the foot which your talking about is done during acceleration when the goal is to apply as much force as possible over an extended period of time.
here is a good way to think of it. Run down hill. Do you run faster by trying to push off the ground behind you as hard as you can or by letting momentum carry you down the hill by getting your feet on and off the ground as quickly as you can. The less time you speed on the ground the faster you go down the hill. the same is true when you reach top end speed on a flat surface.
As far as ATP goes. During anything less than 9 seconds in length you use the creatine phosphate system. No oxygen is used.
As a side not lactic acid does not cause what many think it does. Studies have shown that it does not cause the soreness most think. The term lactic acid runs do nothing in the sense of lactic acid. It is actually an energy system not a down side. But that is another story for another date. Sorry your high school coach is wrong. The USATF Doctors have proven it.
dtrack28 wrote:You were right about egos getting in the way which is why inevitably you will respond one last time...guess its hard once you've written a full of ideas you took from someone else to listen to an 18 year old that may or may not have something right.
The issue on this subject is not your age or thoughts. The difference in running and the vault technique is simply how to run correctly and fast is proven. If you talk to any of our Nations top sprint Coaches they will tell you the same things I am. Why do I know this because I was trained by them and hang out with them every year and watch what they do and how they coach. I listen to their conversations and the way they talk to their athletes.
What I am writing is what The USATF (do you know what that is) coaching staff is teaching.
Well this is going no where so I will leave it alone as well. You continue to run with a forward lean for the entire approach and lets see if you reach your maximal potential.
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Carolina21 wrote:So I think it is wrong to say that we should try or intend to strike our foot in front of our COM. The COM is sitting in front of the vaulter and an ideal foot strike would be inline with the vaulter and poles COM.
Whewwww.
I know I never said strike infront of your COM. All I was saying is that your COM of the pole and vaulter system is not under your hips but slightly infront of your hips.
Later
good morning
i have spent a considerable amount of time studying the run.
also tried every technique "innovation" know to man in the 60's to get faster.
went from 11.1 high school to 10.5 (10.72 fat) 5 years later...
personally i don't believe that "pawing" should be taught.... usatf honestly found a "gimic" that actually can hurt the average sprinter... the good ones get their with "pawing' because the repetitions help the equal and opposite reaction...
down hill running and towing doesn't really help a runner learn to apply more force to the track... downhill runners.. because of less gravity and a better strike angle lets you run faster with less effort..
one of the characteristics of speed is the ankle flexibility with faster sprinters having a greater angle letting the foot strike be more of a down and back motion...
has anyone read the harvard study on speed? i thought i posted it??
if you can find it.. jim bush has a speed video... i think he approached it pretty good...
personally i don't put pawing, clawing, leg extension exercises in my training .. and feel it is the wrong focus and leads to leg problems.. hams in particular..
i emphasis keeping the toe behind the knee on every stride......i do "knee drives" not high knees.. where the athlete strikes the track with the ball of the foot under the COM.. butt kicks.. skips .. quick feet...
pull the slide.. uphill runs and rhythmic stride sprints.. with the pole
and have had success getting everyone faster...
later
dj
i have spent a considerable amount of time studying the run.
also tried every technique "innovation" know to man in the 60's to get faster.
went from 11.1 high school to 10.5 (10.72 fat) 5 years later...
personally i don't believe that "pawing" should be taught.... usatf honestly found a "gimic" that actually can hurt the average sprinter... the good ones get their with "pawing' because the repetitions help the equal and opposite reaction...
down hill running and towing doesn't really help a runner learn to apply more force to the track... downhill runners.. because of less gravity and a better strike angle lets you run faster with less effort..
one of the characteristics of speed is the ankle flexibility with faster sprinters having a greater angle letting the foot strike be more of a down and back motion...
has anyone read the harvard study on speed? i thought i posted it??
if you can find it.. jim bush has a speed video... i think he approached it pretty good...
personally i don't put pawing, clawing, leg extension exercises in my training .. and feel it is the wrong focus and leads to leg problems.. hams in particular..
i emphasis keeping the toe behind the knee on every stride......i do "knee drives" not high knees.. where the athlete strikes the track with the ball of the foot under the COM.. butt kicks.. skips .. quick feet...
pull the slide.. uphill runs and rhythmic stride sprints.. with the pole
and have had success getting everyone faster...
later
dj
Come out of the back... Get your feet down... Plant big
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The downhill point was not a suggestion of how to train but to make the point if you only focus on driving your foot behind you once you hit top end speed you will have to much forward lean and stumble.
Yes if you really want to get into it the more important factor is the dorsiflexed ankle. So that your achillis tendon is loaded. the original topic was not based on this fact but the driving motion behind you once you reach top end speed.
I also agree the toe should never move out infront of the knee.
hence the step over the opposite knee than tap the foot to the ground.
The object of the pawing action in normal running is to land directly under your COM with a dorsiflexed ankle. The toe should never drop below the heel. If it does it creates the raking action that causes stress on the hamstring. Otherwise if performed correctly which should be the goal it puts little stress on a developed athletes bodies.
I think a problem we should be more concerned with is the constant Remark RUN ON YOUR TOES. Problems in your Knee, Shins, Hips, Hamstrings etc. Don't let your toe drop below heel (keep shin flexed) and don't let the foot drift in front of the knee and which ever style you use you will run faster.
As DJ remarked the dropping of the toe is causing more damage to speed and injuries than the pawing action.
Yes if you really want to get into it the more important factor is the dorsiflexed ankle. So that your achillis tendon is loaded. the original topic was not based on this fact but the driving motion behind you once you reach top end speed.
I also agree the toe should never move out infront of the knee.
hence the step over the opposite knee than tap the foot to the ground.
The object of the pawing action in normal running is to land directly under your COM with a dorsiflexed ankle. The toe should never drop below the heel. If it does it creates the raking action that causes stress on the hamstring. Otherwise if performed correctly which should be the goal it puts little stress on a developed athletes bodies.
I think a problem we should be more concerned with is the constant Remark RUN ON YOUR TOES. Problems in your Knee, Shins, Hips, Hamstrings etc. Don't let your toe drop below heel (keep shin flexed) and don't let the foot drift in front of the knee and which ever style you use you will run faster.
As DJ remarked the dropping of the toe is causing more damage to speed and injuries than the pawing action.
- Carolina21
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Speaking with a friend of mine who is a doctor and has studied the human body fairly intensely here is some info I found interesting: an average person's center of mass (COM) is actually located directly in front of your second back vertebrae above your hip (pretty close to the back of your body), so as we discussed this we thought that even with a pole vaulters' COM being shifted forward due to the weight and torque of the pole, it would most likely still be located "in" their body and not in front of it. Just food for thought. This would still lead to a foot strike under the body.
-Rise to the occasion
PR: 18' 4.0
PR: 18' 4.0
Sprinting whilst the arms support a vaulting pole is not at all the same problem as arms -free (unloaded) sprinting. In free sprinting the arms perform a reciprocating action and play a role in counter -balancing the tendency for the athlete's COM(centre of mass) to be slightly displaced laterally in the frontal plane at each footstrike. Not is this imbalance under arm control but arm swing timing and the direction of their displacement in the fore-aft (sagital) plane contribute directly to propulsive impetus during foot contact. They also help control the tendency for the trunk to to undergo some rotatory up / down motion in the sagital plane about their transverse and also the trunk rotation about the sprinter's longitudinal body axis.
The plethora of biomechanics analyses of "free" sprinting show that even world class sprinter's make footstrike contact with the the initial contact point slightly in front of a vertical line projected downwards from their body COM. Consult PubMed and Sports Discus databases. There are many reasons why this is regarded as normative sprinting action behavior.
Sprinting with the body loaded with a long lever, gripped in both hands and supported via the shoulder joints and shoulder girdle by the trunk and legs of the vaulter, poses even more demand on the athlete in terms of effective propulsive impulse (force x time) during alternating foot contact of very short duration contact (contact times in top male and female vaulters of 0.08sec to 0.12sec).
Also to be considered is the fact that the pole during the run and plant undergoes a rotation in the plane in which the vaulter and pole are being translated forwards in the direction towards the plane of the cross bar and the vaulting box. The pole rotation from a 70 degree angle to the horizontal to about 30 degrees at the time of the initial contact of the final step on to the take-off foot creates a moment (torque) that will cause the vaulters trunk to flex and incline forwards from the hips in the direction of the run.
A footstrike directly below the pole and vaulter total COM causes a vertically upward reaction opposite in direction to the athletes body weight. Because of the linear speed of forward translation of the total system COM immediately following initial foot contact made in this way, the resultant ground reaction force will contribute a high vertical force component at some distance rearward from the vertical line from the vaulter and pole system centre of mass. This vertical component contributes to increasing the torque applied about the transverse axis through the COM in the directional sense towards the runway to the front of the vaulter. This exacerbates the tendency for the pole to rotate the vaulter's trunk, upper apendages and pole to rotate.
To cut a long story short when carrying a long pole held in the hands the initial footstrike contact point should be made slighty in advance of the vertical line projected downwards from the total system COM. This is required in order to facilitate balance and dynamic stability throuhout the braking and propulsive phases of the foot contact.
Sprinting with a pole requires controlled maximum speed and precision at
the final take-off step to effectively transfer the kinetic energy of the run into stored potential energy in the pole.
because it is rearward to the location of the COM will
The plethora of biomechanics analyses of "free" sprinting show that even world class sprinter's make footstrike contact with the the initial contact point slightly in front of a vertical line projected downwards from their body COM. Consult PubMed and Sports Discus databases. There are many reasons why this is regarded as normative sprinting action behavior.
Sprinting with the body loaded with a long lever, gripped in both hands and supported via the shoulder joints and shoulder girdle by the trunk and legs of the vaulter, poses even more demand on the athlete in terms of effective propulsive impulse (force x time) during alternating foot contact of very short duration contact (contact times in top male and female vaulters of 0.08sec to 0.12sec).
Also to be considered is the fact that the pole during the run and plant undergoes a rotation in the plane in which the vaulter and pole are being translated forwards in the direction towards the plane of the cross bar and the vaulting box. The pole rotation from a 70 degree angle to the horizontal to about 30 degrees at the time of the initial contact of the final step on to the take-off foot creates a moment (torque) that will cause the vaulters trunk to flex and incline forwards from the hips in the direction of the run.
A footstrike directly below the pole and vaulter total COM causes a vertically upward reaction opposite in direction to the athletes body weight. Because of the linear speed of forward translation of the total system COM immediately following initial foot contact made in this way, the resultant ground reaction force will contribute a high vertical force component at some distance rearward from the vertical line from the vaulter and pole system centre of mass. This vertical component contributes to increasing the torque applied about the transverse axis through the COM in the directional sense towards the runway to the front of the vaulter. This exacerbates the tendency for the pole to rotate the vaulter's trunk, upper apendages and pole to rotate.
To cut a long story short when carrying a long pole held in the hands the initial footstrike contact point should be made slighty in advance of the vertical line projected downwards from the total system COM. This is required in order to facilitate balance and dynamic stability throuhout the braking and propulsive phases of the foot contact.
Sprinting with a pole requires controlled maximum speed and precision at
the final take-off step to effectively transfer the kinetic energy of the run into stored potential energy in the pole.
because it is rearward to the location of the COM will
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