posted Jun-24-2007 09:14 AM               

quote:

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Originally posted by tigger:

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Both of these items have "coefficients of elasticity" above 50%.

So will the body, and in the case of the conscious person, he/she will consciously store energy and then release it during the jump phase.

I disagree with the word “release”. The fact that they are conscious or unconscious would not change the physics of their biological system. When they are conscious they re-activate the muscle to relaunch their body upward. They are not releasing stored potential energy, they are converting biochemical energy to kinetic energy thorough conscious effort.

I think you have already agreed there is at least some spring release action in a muscle, so I think we are only talking about the amount or degree of energy available for release in this manner.

I think that the energy return is very small, in the area of single digit percent.

Ted

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posted Jun-24-2007 10:14 AM               

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posted Jun-24-2007 01:11 PM            

quote:

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Originally posted by hopper3011:
Ted,
There is a certain amount of literature on the subject; I've found a few studies for you:
Roberts TJ, Marsh RL, Weyand PG, Taylor CR. Muscular force in running turkeys: the economy of minimizing work. Sci Mag 1997;275:1113–5.
McMahon TA. Spring-like properties of muscles and reflexes in running: multiple muscle systems. Biomech Movement Org
1990;37:578–90.
Ker RF, Bennett MB, Bibby SR, Kester RC, Alexander RM.
The spring in the arch of the human foot. Nature 987;325:147–9.
Farley CT, Gonzalez O. Leg stiffness and stride frequency in
human running. J Biomech 1996;29(2):181–6.
As you can see, the muscles and tendons of the lower limbs do return significant energy to the running stride.

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Thanks Hopper. The book I mentioned to brianfie was written by a materials engineering professor from England. He had an interesting discussion in it about energy stored in tendons used to string English longbows. This extra energy was one of the reasons arrows could be shot farther than any enemy archers could achieve.

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posted Jun-25-2007 12:22 AM               

quote:

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Originally posted by tigger:
The weather will always surprise you here in the coastal mountains. Several days ago we had a snowstorm. The bears must have been pretty confused! Overall though, it's a great place to run....never too hot and always scenic.

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I would love it! I have not made it to your part of the world yet. It remains a goal. Right now I have chosen to live in a Mediterranean climate. Good for sailing.

-b

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posted Jun-25-2007 12:41 AM               

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Originally posted by TedAndresen:

Suppose someone is unconscious and they are placed in an upright position with their knees bent to the same angle that they would be bent during foot-strike in running and their quadriceps were electrically stimulated so they supported the person’s weight.

If you then raised them up to a height similar to the height that someone reached when they were running, or hopping in place and dropped them, would they bounce?

Would the leg of an unconscious person with a leg that was electrically stimulated so it could support their weight, act like a spring?

I don’t think it would? I think that conscious contraction causes the rebound, not that the quadricep behaves as a spring.

Ted

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I think the unconcious person would bounce. Might not be enough of a bounce to leave the ground, but nonetheless, enough of a bounce to be highly significant in runnning. Furthermore the natural frequency of the bounce will be close to the preferred step rate of the person when he or she wakes up and makes their getaway!

-b

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posted Jun-25-2007 01:05 AM               

http://links.jstor.org/sici?sici=0962-8452%2820031022%29270%3A1529%3C2173%3APFFIBG%3E2.0.CO

Another thought....

In runnning, there is a lot of eccentic muscle loading going on. I have a dim memory of reading somewhere that the behaviour of muscles, even the phisiological processes, are different in this mode.

Must try and look it up...

-b

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posted Jun-25-2007 10:56 AM               

quote:

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Originally posted by tigger:
He had an interesting discussion in it about energy stored in tendons used to string English longbows. This extra energy was one of the reasons arrows could be shot farther than any enemy archers could achieve.

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posted Jun-25-2007 02:24 PM               

These are all references to great researchers in the field. But, you have to be careful when you read the papers and the abstracts. In many cases they are writing about the elasticity of the tendons. Tendons return more of the energy of deformation than muscles. Unfortunately, the tendons are in series with muscles, so the benefit of having an elastic tendon in the force chain is masked by the inelastic behavior of the muscle.

None of the articles that you cited actually offer an estimate of the overall elasticity of the total muscle/tendon chain. Most of them are referring to the components of the chain that return a small amount of the input energy.

Here are just a few examples from the abstracts:

In “Muscular Force in Running Turkeys: The Economy of Minimizing Work “ by
Thomas J. Roberts, * Richard L. Marsh, Peter G. Weyand, C. Richard Taylor the abstract begins with:

“During running, muscles and tendons must absorb and release mechanical work to maintain the cyclic movements of the body and limbs, while also providing enough force to support the weight of the body. Direct measurements of force and fiber length in the lateral gastrocnemius muscle of running turkeys revealed that the stretch and recoil of tendon and muscle springs supply mechanical work while active muscle fibers produce high forces.”

The phrase “must absorb and release mechanical work” doesn’t imply what portion of the energy absorbed is stored in the muscles and tendons and then returned during recoil, only that some is absorbed and released as mechanical work (energy). Absorption of energy does not mean that it can all be recovered.

The phrase “the stretch and recoil of tendon and muscle springs supply mechanical work while active muscle fibers produce high forces” does not state how much energy is recovered, only that they supply mechanical work. No one in the peer-reviewed literature has indicated that the amount of returned energy is very large. Most of the work energy required to re-launch the runner into the air at toe-off occurs when the “muscle fibers produce high forces.” These forces are created through biochemical processes, not mechanical energy recovery.

In “The spring in the arch of the human foot” by R. F. Ker*, M. B. Bennett*, S. R. Bibby†, R. C. Kester† & R. McN. Alexander*

“Large mammals, including humans, save much of the energy needed for running by means of elastic structures in their legs and feet. Kinetic and potential energy removed from the body in the first half of the stance phase is stored briefly as elastic strain energy and then returned in the second half by elastic recoil. Thus the animal runs in an analogous fashion to a rubber ball bouncing along. Among the elastic structures involved, the tendons of distal leg muscles have been shown to be important. Here we show that the elastic properties of the arch of the human foot are also important.”

Again that this does state how much of the energy is returned after compression. This is a qualitative statement.

You can actually do a simple calculation of the energy required for leg compression while running a mile. It would be in terms of so many in Joules/mile

By analyzing the leg as a spring you can calculate the amount of energy in Joules that it stored in the leg during compression at each step. Approximately, the energy is:

0.5*LegStifness*CMDisplacement^2.

Last year I got some treadmill data from the University of Jena for my work on the spring-mass model. The 200-lb subject in this study ran at different speeds from 0 to 5.3 m/s. At 3 m/s (~9 min/mile) the subject’s CMDisplacement was 9 cm. Their LegStiffness was ~15,666 N/m so the amount of energy they put into each leg compression was ~150 joules. Their step rate was 2.66 steps/sec (160 steps/minute) so they put about

150 J/step * 160 steps/min * 9 min/mile = 210,000 joules/mile into spring compression while running a mile.

That is assuming that no energy is recovered from the compressed leg. This is just the energy that is used in compressing the leg 160 times per minute while running at 9 min/mile. It assumes that there is no recovery of energy from the compressed leg.

To figure out how much energy the runner is consuming, there is a concept in biomechanics called the “total metabolic cost of transport”. In the US you may know it as the metabolic cost of running or 100 kilocalories/mile. (It is mistakenly referred to as calories/mile.)

It is not truly a constant; it actually depends on the mass or weight of the subject. The 100 kilocalories/mile would apply to a 140-lb (70-kg) person. For a 200-lb runner in the data from Jena, it would be 100 Kcal/mile*200/140 or 140 kilocalories/mile.

If you convert the 140 kilocalories/mile to energy in Joules/mile using the mechanical equivalent of heat (1 Kcal = 4186 Joules) you get 586,000 Joules/mile in metabolic O2 energy consumption. That’s the total energy input to the runner per mile.

If the runner is considered to be roughly 35% efficient in converting metabolic energy to mechanical energy, then the runner is expending ~205,000 Joules/mile in mechanical work while running.

Now, if the runner is expected to generate ~205,000 Joules of energy from metabolic consumption and running requires about the same amount of energy (~210,000 joules/mile), then the amount of energy that is recovered from the spring compression is not a big contributor to balancing the energy budget of the runner. It looks like the energy recovery from spring compression would be a very small if not an insignificant portion of the energy budget.

Because of that and the “thought experiment” with the unconscious runner (above), I believe that recovered energy from leg compression is very small.

Ted

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posted Jun-25-2007 03:21 PM               

Where does the figure for "total metabolic cost of transport" come from? Is this measured, or is it a theoretical value?

-b

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posted Jun-25-2007 03:24 PM            

quote:

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Originally posted by TedAndresen:

Because of that and the “thought experiment” with the unconscious runner (above), I believe that recovered energy from leg compression is very small.

Ted

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TEd,

I find it interesting that, faced with some investigations and reports you prefer to rely on the "data" from a thought experiment. Where is the data in your thought experiment?

Anyway, believe what you will. It seems that nothing will change your opinion so I won't bother with this anymore.

I am not an expert on the differences between muscle and tendon but I remember reading somewhere that tendon is merely muscle a it narrows for attachment to the bone strucure.

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posted Jun-25-2007 03:52 PM               

quote:

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Unfortunately, the tendons are in series with muscles, so the benefit of having an elastic tendon in the force chain is masked by the inelastic behavior of the muscle.

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quote:

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But, you have to be careful when you read the papers and the abstracts.

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posted Jun-26-2007 02:16 AM               

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Originally posted by: Brianfie

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Where does the figure for "total metabolic cost of transport" come from? Is this measured, or is it a theoretical value?

Brian,

First of all, if you are going to do any work where you convert units from one form to another, I you already don’t have a copy, you should get a copy of Converte.exe. It is a wonderful utility.

You can find it at:
http://joshmadison.com/software/convert/

The total metabolic cost that I use comes from a paper by Chad Harris, et al., “The Effects Of Running Speed On The Metabolic And Mechanical Energy Costs Of Running”.

It is on the web at:
http://fig.cox.miami.edu/~cmallery/113/run.speed.energy.pdf

Under DISCUSSION, he refers to it as “metabolic cost per distance (MBTC)” and cites a value in the area of 1 Kcal/(kg-m), which is equivalent to 0.20 ml of O2/(kg-m). They are interchangeable. Most runners are familiar with their O2 consumption in the form of ml of O2/(kg-min), not ml of O2/(kg-m).

One liter of O2 contains 4.83 Kcal, so 0.20 ml of O2/(Kg-m) * 4.83 Kcal/1000 ml * 1000 m/Km gives approximately 1 Kcal/(Kg-Km). That can be converted to Kcal/(lb-mile).

1 Kcal/(Kg-Km) * 1 Kg/2.2 lbs * 10 Km/6.2 miles is the same as ~0.75 Kcal/(lb-mile). If someone weighs 150 lbs, then they will consume about 112 Kcal for every mile they run or walk, no matter how fast.

Interestingly, the body roughly holds about 2000 Kcals, so a runner burning ~100 Kcal/mile will run out of energy at about 20 miles. That’s where “the wall” is. Of course, it varies from one person to another, but 0.75 Kcal/(lb-mile) is a good estimate of the total metabolic cost of transport.

Since a 1 Kcal is equal to 4200 joules, you can see that it takes about 3000 Joules/(lb-mile). The total metabolic consumption for the 200 lb runner I referred to above would be about 600,000 joules/mile.

quote:

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Originally posted by: hopper3011

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Ted, you have this completely arse about face, tendons are inelastic, muscles are elastic.

Hooper,

I think that you are confusing two terms: elasticity and elongation or strain. They are not the same.

There are two references below that will help clarify the issue. The first is from Wikipedia. It might suite your needs. The seconds is from the Sports Injury Bulletin. It is not peer-reviewed but their description of the muscle-tendon complex (MTC) is pretty good. The last paragraph, “How tendons work”, is on point.

From:
http://en.wikipedia.org/wiki/Elasticity_%28physics%29

A material is said to be elastic if it deforms under stress (e.g., external forces), but then returns to its original shape when the stress is removed. The amount of deformation is called the strain.

The elastic regime is characterized by a linear relationship between stress and strain. Because most materials are only elastic under relatively small deformations, several assumptions are used to linearize the theory.

From:
http://www.sportsinjurybulletin.com/archive/muscle-tendon-complex.htm

What is the muscle-tendon complex?

Muscles do not contract in isolation; rather, movement occurs when muscles connected to tendons generate and then transmit contractile forces. Crucially, the muscles and tendons interact, with the elastic properties of the tendons contributing both to the type and quality of movement. In almost all movements, when the muscle contracts, the tendon will lengthen before it shortens, independent of any change in muscle length. This property of ‘recoil’ enables elastic energy to be stored and released, thereby increasing the efficiency of the muscular contraction. So movement is a combination of two factors within the muscle- tendon complex:

muscle forces transmitted through the tendon to the joint;
elastic energy recoil of the tendon.

How tendons work

It is helpful to think of the tendon behaving like an elastic band. The more force applied through the length of the tendon, the longer it will be stretched (until maximum strain is reached, when it snaps). When the stretch is released (the ping of the elastic band), most of the mechanical energy is recoiled, with the rest being lost as heat.

quote:

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Originally posted by: tigger

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I am not an expert on the differences between muscle and tendon

tigger,

You might take a look at the preceding paragraph.

Ted

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posted Jun-26-2007 05:33 AM               

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posted Jun-26-2007 05:59 AM            

You say, and I agree that it it is helpful to think of tendons as elastic bands yet you minimize the idea that they migh contain significant amounts of stored energy. Elastic bands store energy. So do tendons.

Elastic deformation will store enormous amounts of energy, including in metals such as steel. The energy can be calculated by knowing the amount of elastic deformation, or even by knowing the applied stress. This is a simple task for any mechanical engineering student.

Over time I have known you to be what I call a "data freak" or in simple terms, someone who is convinced by data, not by qualitative discussion. Twenty years ago this area of study was my home, and I spent many happy hours analyzing materials in both elastic and plastic behavior. I am too far away from that now to get into the details of a quantitative discussion on stress strain curves and elastic or plastic deformation, so instead I urge you to spend 4 bucks and get the book by Gordon. If nothing else you will be entertained for several hours.

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posted Jun-28-2007 12:24 AM               

I’d rather be a troll (a social position once referred to as the court jester so thank you) instigating a different perspective than throwing articles back and forth. How is knowing or arguing how a tendon alters form going to impact how we run?

We have tendons and they change form, I don’t argue that. I see them more in the role of being shock absorbers for muscles. Since muscles fire with incredible quickness, the role of the tendon would see us as moving in an incredibly jerky and more mechanical or rigid form than we currently do if we didn‘t have them. I could say that we probably couldn’t run as we do if we didn’t have tendons as part of our muscular system.

In my eyes, they’re what bring fluidity to our movement. When muscles fire, that stretching ability of a tendon buffers transferring the intensity of a firing muscle, with the insertion into the bone it controls. I think they smooth out and give us better control and also protect the muscles from tearing if we push their movement envelopes, especially in activities like weight training.

What I question is whether or not we use our tendons in the most complementary methods to our running form. I prefer to see their role as a compliment to the power and strength of a muscle and how to best utilize their ability in running.

Comparing them with springs doesn’t do them justice. And since people hopping in place aren’t running, then I don’t feel such analogies apply to explaining how the human body works.

What I look at is the size of each muscle in the running process compared with the length of tendons connecting them with our skeleton. The longer a tendon is in ratio to attached muscle mass demonstrates the biomechanic opportunity for optimizing their elastic ability to conserve running energy and achieve highest speed possible.

I want to know how best to utilize and load one’s tendons with the greatest stored energy for push off and maximum speed.

And the tendons with the least amount of muscle fibers, and therefore most elastic, is the tendon runners refuse to implement into their running biomechanics at all. So if you won’t use the tendons you have, and rob yourself of improved speed, then tit for tat article tossing like grenades misses the bigger picture of what they are and how to best use them.

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posted Jun-30-2007 12:59 PM            

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posted Jul-01-2007 05:00 AM               

quote:

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Originally posted by laker:
Jester,
your last post was typically useless. You only like science if it supports your wild theories, which surprisingly never seems to happen. Seems to me you would have to understand how the body works in order to use it more efficiently, but not in your world.

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posted Jul-02-2007 10:57 AM               

Considering that running coaches know very little about anatomy, let alone how to run, your comment means little...

And as I stated earlier, I've had multiple conversations, e-mail exchanges with Nike's top biomechanic and sports lab manager, so quality of what I know is only disputed in your mind, and your e-mail address isn't Nike.com...

I was certified as a USATF coach, and NOTHING about anatomy was even discussed, except the fact that humans can't run straight, even though they gave no reasons why, or how to correct it. So you can tell me why can't you...

My conversations of anatomy and use mean little to you as I'm not interested in how humans move, but how they can move.

Which is interesting because you didn't "dispute" the strongest tendon of running biomechanics isn't used by runners anyway. So why not?

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posted Jul-02-2007 02:20 PM            

WAIT!!!!! I know who the Jester really is. He's Tony little. You can dooooo it!!!!!!!

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posted Jul-02-2007 03:57 PM            

quote:

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Originally posted by sport jester:

I was certified as a USATF coach, and NOTHING about anatomy was even discussed, except the fact that humans can't run straight, even though they gave no reasons why, or how to correct it.

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Next you'll be telling us that's the reason tracks are oval...to accommodate the imperfect human running gait.

I guess observations of birds circling in the air should lead one to conclude they have one weak wing and one strong one.

Yes, you're certified for sure! Sheesh!!

[This message has been edited by tigger (edited Jul-02-2007).]

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posted Jul-02-2007 06:07 PM               

quote:

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And as I stated earlier, I've had multiple conversations, e-mail exchanges with Nike's top biomechanic and sports lab manager, so quality of what I know is only disputed in your mind, and your e-mail address isn't Nike.com...

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posted Jul-03-2007 06:04 AM               

In fact, I think it is true that all animals that run on two legs must use elastic recoil to be efficient. Let me see, we have humans, many birds, kangaroos. Can anyone come up with a single efficient two-leg running animal that does not use elastic recoil?

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posted Jul-03-2007 02:35 PM               

quote:

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Originally posted by olderthandirt:[/B]

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Go to http://www.scholar.google.com/ and enter in running and elastic recoil.

Scholar.google,com is a very good research tool. However, you should be careful when looking at the literature that was published before the late 80’s on this important issue

The thinking has evolved considerably since the spring-mass model was introduced ~1988 and developed as an analysis tool. Before that time, most research made reference to the spring-like nature of muscle-tendon-complex (MTC) and energy recovery, but very little experimental evidence was presented to back up the assertion. Many papers before 1990 make reference to the spring-like behavior of the MTC, but they failed to offer any direct measurements of the amount or percentage of recovered energy.

Many important researchers contributed to the development and refinement of the spring-mass model. After it was implemented on computers it was possible to quantitatively represent the runner and compare the model’s output parameters with real-world measurements. The creation of the model made it difficult to speculate about recoil energy recovery. Beyond 2000 you will find fewer authors who are willing to offer quantitative estimates on the recoil energy recovery from MTC compression.

Do not confuse energy recovery from total leg compression with elastic recovery from tendons. Energy stored and released from tendons is a small issue because tendon elongation is only a small portion of the overall system’s elongation.

To a good extent the spring mass model explains the mechanical cost of transport (~1.3 J/(kg-m)) without the need for recoil energy.

If you find any peer-reviewed research after 2000 that quantitatively offers findings in the specific topic of recoil energy from the MTC that are backed-up by real-world measurements, would you bring them to our attention.

Ted

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posted Jul-07-2007 08:42 PM               

Your need to “help others?????” Oh please….

I’ve yet to read anyone begging in print for the “Opinion of Hopper” to validate their perspective of how I teach running…” Do you also offer to cut their dinner meat to keep them from choking?

So get Galloway to join this…

And yeah, you probably could well be a faster runner than myself, but if I can run straighter, I’m in reality running the shorter distance and would beat you anyway… So Hopper, what’s your (Google Forward Drift OK???) Forward Drift rate anyway, since you never mentioned it….

Or you can read:

http://www.swarthmore.edu/SocSci/fdurgin1/publications/DurginFoxKim2003.pdf

In fact your opinions are never accompanied by any math to discredit what I bring to the table. Since I run perfectly straight and you don’t, linear distance ability trumps speed any day. You’ve never posted your abilities in real numbers, so what reference do you offer for me to even begin to think about anything other than laughing at your posts?

Please keep writing because I quote you on a regular basis with running students as to what people think of me (FYI, you’ve stated nothing original by the way…) so you provide me with an archaic perspective that my students also agree with until they tell me that they’ve learned more about running from me in a twenty minute conversation than from any running coach, physician, surgeon, or physical therapist has taught them in months or years.

I see you as the self proclaimed company “expert” on running, and with that need to defend your worthless title. So spare me helping others when it’s your own psyche that needs serious help.

Tigger is getting it, and beginning to think differently. While he jokes about his observation, he’s looking at what he once took for granted and postulating a reason for why birds circle in the directions that they do. That’s intelligence at work, something that you have yet to indicate any measurement of to me.

Oh, and while I reference horses knees instead of their Latin name for the joint, is something important to you, or that Sherpas carry weight on their backs as well as above their heads as I wrote, that to me isn’t mathematical proof that I don’t know what I’m talking about.

I don’t claim to be an expert in Sherpas, or referencing a joint by it’s more common rather than factual name is an error I fully admit, however such factual errors have nothing to do with the biomechanic math I work with.

I make mistakes, and I’ll fully admit that. And if you read the article about me, you would have noticed that I perfected my running technique in 2000 (as the article was published in 2001 and thus before the Kenyan women article was even posted so please explain that time line to me. The only fact following both is that I taught seven out of ten firefighters to carry 60 lbs of gear with no heart rate increase compared to walking without it.

So for the description of being a quack, why can’t your experts explain how the women walk? If I’m not right, then how do women walk carrying 20% of their bodyweight in firewood with no increase in heart rate?

Give me your math of explanation.

Since I use formulas relating to the pendulum arc of torso rise (vertical rise, linear rise, or the more common name of a runner’s “bounce” (to cover the greatest language reference and pre-apologize for missing any) to explain both the women and the cheetah’s mastery of sprinting ability. While I can easily explain both, neither you nor your quoted experts can explain either...

As a runner, you might not appreciate such feats as extraordinary, but for backpackers the ability to carry 20% of their bodyweight with no heart rate increase is quickly recognized. For a 200 lb adult to carry a 50 lb backpack with the physical exertion needed for carrying only 10 lbs is most appreciated and rewarded…

While every biomechanic in the world can’t explain how the women of Kenya walk, I can. And I’m also the only one who can reproduce the walking efficiencies they practice.

So all I did was connect a few dots (you know, the ones that take intelligence to figure out) as to why the best Kenyan distance runners, the most efficient walking women, and the world’s fastest sprinter as a cheetah is, all come from the same place on earth.

Lacking the intelligence to comprehend their relationship isn’t my problem, that‘s yours.

To me, that isn’t a coincidence. My math is solid. What’s fluid is the intelligence required to comprehend it. Tigger has it and you don’t…

So if that’s your definition of BS, then I’ll take that… But even with small mistakes on my part, I have yet to read anything from you which can back itself up with any math whatsoever…

And you still have yet to describe the difference in running biomechanics between a cheetah and their prey, as both have four legs, yet one is clearly the faster runner…

Give me math my friend, or your opinions won’t mean much to me or anyone else.

A pathetic narcissistic self image problem by chance???

Hey Tigger,

I extend my highest compliment to your physical extrapolation. What’s true in that all animals are dominant sided no different than humans and each has to compensate or take advantage of that difference. The rotational direction birds fly is a brilliant observation to be honest. You could easily write a paper on it…

If you’re left handed, then you have something in common with Polar Bears as they’re left handed as well.

And yes, the track direction of running counterclockwise is determined by our “imperfect” gait, not the design as you postulated.

More important is that you’re taking my ideas and stretching them in new directions. I never would have even thought about the bird connection, so I’d say go talk to experts in bird behavior, and see if they can link the strength differential story to their rotational direction. That was incredibly cool to read. I honorably thank you…

Connecting strength differential to birds is fantastic and I extend my gracious humbleness.

So if you’re going to call me certified, then maybe we can get a group discount… Because you’re absolutely right…

In the human athlete we’re most commonly right handed. And with that strength differential, humans naturally push themselves toward their weaker side. If I were to place you at the center of a pitch black gymnasium for example, with no visual references to movement you couldn‘t walk straight across the room. You would find yourself slowly walking in a rotational direction counterclockwise toward your weaker side and eventually in complete circles.

Without a visual reference to guide you, walking (or running) perfectly straight is impossible to do.

I always use the classic phrase from the movies “Hey Ed, we’ve been walking for hours in we’ve been going in circles…” That’s not a cheap movie line, it’s both human and animal biology.

Your ability to steer straight given a natural strength differential between your legs is one of the untold skills runners need, but nobody references for you.

Compensation for your natural drift toward your weaker side is a visual skill. And as all skills, unfortunately they have to be tested, improved, and perfected. Can you name for me one running coach who teaches a visual component to their training?

As I’m tested to run perfectly straight, and no street runner can do so, Hopper has no clue as to how far he’s really running. I’m sure that if I put a GPS marker on him, He’d look more like a drunken sailor staggering down the gangplank instead of his elite level fantasies…

Over the course of a road race, with no lines to guide him as a track runner has, Hopper as well as the vast majority of runners may be faster but have no clue as to how far they truly run for any given distance. If I’m faster at the 100 meter sprint, then building the cardio skills to run a marathon would extrapolate easy to beating him in a race.

Running faster means nothing, if you run further for any race difference than your opponent, speed doesn’t matter as you‘ll still lose.

So in a track environment, the counterclockwise rotation takes advantage of the most common right leg dominance by utilizing the natural circular path to allow a runner their highest speed possible.

And my absolute compliment to your bird observation because I enjoyed it immensely…

Olderthandirt,

You made reference to the elasticity of tendons in animals which I appreciate because biologists are well aware of how lacking of muscle structure most animals such as horses, gazelles, antelope or others similar in biological makeup of their lower limb structures truly are.

They use tendons with a much greater efficiency than humans do and evolved with very little muscle attached to them. For humans, altering and improving our tendon use requires altering our balance to maximize changing the weight loads and balance skills necessary to utilize our tendons as efficiently as horses, deer, elk, or even rabbits do…

Maybe you’ve noticed that very few running quadrupeds have calf muscles as humans do. Even the highest leaping animal in ratio to bodyweight, the grasshopper, doesn’t have a calf muscle…

Hopper should know why…

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posted Jul-07-2007 10:25 PM            

1) Is it farther to Atlanta or by bus?
2) Do you buy your lunch or do you eat it?

Now while you're working on those ones I'll go for a short run and dream up some more.

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