Five major points - barefoot vs shod

Sorry Eric, I edited while you were writing. I asked about differences in coefficient of friction at each interface too.

But if the reaction forces on the foot side of an interface material are the same as the reaction forces + the weight of the material at the force plate side of the interface, then to answer Leo's question- a force plate should give a reasonable approximation of the in-shoe forces-right? Or, does the surface angulation at the foot-shoe interface and the variation in frictional co-efficients influence the situation too much? Thanks for your thoughts.

 

His original question was about vertical forces and yes a force platform should give a very good aproximation of dropping a cadaver limb in a shoe from a height and measuring the vertical forces. The frictional charachteristics of the material could very easily induce behavioral changes that could change the value produced from a force platform in walking. There would be a huge number of variables to control for, as well as some technical problems to be able actually test the assertion that it is a close aproximation of the forces in walking.

I'll have to think about horizontal forces a bit. Behavioral changes will probably be greater relative to the magnitudes of the forces.

Eric

 

Hi Eric,
Like I said previously there is no direct evidence on running shoes versus injuries that tell us presently what to prescribe to our patients, except :
* the 3 of Knapik -type of shoes vs type of foot-;
* the 3 of Ryan (The effect of three different levels of footwear stability on pain outcomes in women runners: a randomised control trial/Examining the degree of pain reduction using a multi element exercise model with a conventional training shoe versus an ultraflexible training shoe for treating plantar fasciitis) -the third one will be publish soon on minimalist vs traditional- ;
* and some other on the way (not publish yet, like here at Quebec)

But there is indirect evidence showing that depending on the type of shoes you wear (or not) you will have different type or 'biomechanics' (the tendency is clear)... and that this type of biomechanics will increase or decrease the stress on some tissues. (ex : barefoot-minimalistic running increase the forefoot loading, decrease the work of the tib anterior and decrease the tissue stress of the anterior compartment syndrome... it's just ONE example of the integration of that... I will therefore recommend to a patient with a anterior compartment syndrome to avoid a heel lift and promote for them a very minimalist shoes. It's presently the only way we have to recommend / prescribe shoes based on science... even it's correlation and flimsy evidence.

EKAM : External Knee Abduction Moment

I think my question are VERY clear and simple... (see my answers). One of the thing I observe on this blog it that people critic everything, say always 'there is no evidence' and never take position... I feel that most of people stop to be clinician and stat to be just critics ... maybe I'm wrong

Do you think that moving to a minimalist shoe from a maximalist shoe have no risk to develop the type of injuries Craig named, like a MT stress fracture? (NO, it's risky if it's done too quickly)
Do you think that maximalist shoes doesn't decrease the stress on the foot -generally-? (NO, it decrease the stress/load)
Do you think that traditional shoes doesn't increase EKAM? (NO it's increase EKAM for most of shoes and runners)
Do you think that maximalist shoes lowering the risk of injuries on long term?(No I think it increase)

 

Blaise, I'm trying to tap into some knowledge here and your the heckler at the back of the class. Cut it out!!!!

 

And if you decrease the external knee abduction moment, you increase the external knee... something... can you guess? External knee "something" moment... what is that "something"? Anyone? Anyone? External knee something moment? Anyone? External knee something a,d,d, moment? Anyone? Anyone? External knee adduction moment... "
"Bueller? Bueller? Anyone? Anyone?" http://www.youtube.com/watch?v=uhiCFdWeQfA&feature=related

And if you increase the external knee abduction moment, you decrease the external knee... something... moment? Can you guess?

Fill in the blanks, Blaise. Then you might realise why you cannot make statements like the ones you made previously.

"But you didn't answer my questions" ... because I knew you didn't understand the claims you were making. So, to answer some of your questions: to say that one type of shoe increases or decreases the risk of injury at the knee joint (or foot) as a whole, is just nonsense; the potential risk of injury at the knee joint is merely shifted twixt tissues at that joint. It's a classic example which Eric described beautifully in a chapter that might get published one day- draw it out as a free body analysis, Blaise.

Passion is no replacement for knowledge and understanding, and if you don't understand what the evidence tells you, you cannot possibly employ an evidence based approach within your teaching nor clinical practice. And if your "passion" has nothing to do with money, then put your courses on for free.

 

May I ask another question?
As far as I know, research shows that when you put a cushioned shoe on, impact forces go up. Of course researchers always state that it is a counter intuitive finding. I do understand that strike pattern and "shock moderating behaviors" change, but I also recall a concept purposed that the foot is "searching for an input signal" and thus purposefully hits harder in this "search". I've never been able to get it out of my head that perhaps perception is reality and the CNS is not searching but rather responding to the fact that landing on a cushioned material with no rocks, glass, or whatever, has less potential to create immediate harm to the foot. Thus the pattern employed by the CNS is perfect for the nature of the external environment in which it is landing, ie- cushioned.
So, I guess the question is - Is the foot "searching" for input or is perception reality.

 

That's the Robbins-Gouw hypothesis. Show me the evidence that supports this, other than that reported by Robbins and Gouw? In my view, it responds to the input as noted by Farley and all. The only challenge to that might be observed from studies of sensory neuropathy.

 

We have had a number of threads on the Robbins-Gouw hypothesis, but essentially they did some good experiments and I agree that they are probably right that with something soft under the foot, there probably is some changes impact moderately behavior.

However, what Robbin and Gouw and those that blindly tout their work have had an epic fail on is that no one has actually demonstrated that there is anything wrong with the change in impact moderating behavior that the shoes induce! Just because you editorialize some research and state that the change in impact moderating behavior induced by shoes is bad, does not mean it actually is. No one has done any research to show that there is actually anything wrong with it!

 

The heel lift will be important if the touchdown angle remains the same between the shoe with the lift and without the heel lift. (Touchdown angle, in this case, is the angle, in the sagittal plane of the plantar surface of the sole of the shoe and the ground at heel contact). The theory is that if the anterior compartment muscles, (most likely anterior tibial muscle) has to work longer with a heel lift shoe then there will be more stress on the anterior compartment. However, if in the shoe with the lift the sole of the shoe has the same touch down angle as the shoe without the lift then there will be no difference caused by the lift. Another way to reduce stress on the anterior compartment is to shift the contact point more anteriorly with the shoe design. A flare that goes from dorsal posterior to anterior inferior could acomplish this. A SACH heel probably will do this. A shoe with a posterior flare would make the anterior compartment worse. The point is you can design the shoe for the pathology. Always saying that you should get into minimalist shoes will hurt some people.

The reason that you think that your questions are clear an simple is that you think you know what a minimalist and a maximalist shoe are. I don't know what you mean by that.

Blaise, I have some strongly held beliefs that I have no evidence for. I can clearly explain the logic for those beliefs. I can describe the experiment that could be designed to test those beliefs and I'm perfectly happy saying that yes this is what I believe even though there is no evidence. I'm not quite following your logic between the studies you discuss and your conclusions. Are you saying that a maximalist shoe, whatever that is, is bad for everyone?

Yes, anything that shifts the center of pressure laterally will tend to increase external knee abduction moment (EKAM). A lateral flare on the shoe will make this worse. A dual density midsole (firm medially) will decrease EKAM.

Increasing EKAM will be good for genu varum and bad for genu valgum.

The wrong shoe can increase risk, the right shoe will decrease risk. It will depend on the anatomy of the wearer. No one shoe will be right for everyone.

Eric

 

Simon and Eric,
What do you think of the Gross study : http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=80278

Just to explain just a little more
My thought about injury risk :
- higher if you change not enough gradually (both side)
No strong data on that but ask to Kevin, Craig, and clinicians that treat runners doing this transition to quickly : Giuliani 2011, Leong-2010, Salzler 2011... but safe if integrate gradually : Allison 2012(P)

- lower on your foot on short term with maximalist
Generally, running shoes cushioning decreases the stress / peak pressure on the foot (Rethnam 2011, Tessutti 2010, Wiegering 2009, Wegener 2008, House 2002, Windle 1999, Nyska 1995)

- lower on your knee on short term with minimalist
Running shoes cushioning increases the mechanical stress on the skeleton (except the foot)... (Rethnam 2011, Hamill 2011, Lieberman 2010, Bergmann 2010, Braunstein 2010, Kerrigan 2009, Shakoor 2006, Divert 2004, Shorten 2002, 1996 Hennig, Bergmann 1995) … or doesn’t decrase it (Hardin 2002, Cole 1995, McNaire 1994, Nigg 1987)

- lower on long term with minimalist... ... ... ...
to complexe to explain... follow my course

 

Aloha,

How about 5 really small reasons?

Bacterial infections are typically caused by normal flora bacteria, such as species of Staphylococcus (staph) and Streptococcus (strep). They may also be caused by colonizing bacteria and antibiotic resistant bacteria, such as MRSA (Methicillin Resistant Staphylococcus aureus). Brackish water wound infections may be due to waterborne Vibrio or Aeromonas species. Hot tub-associated infections may be caused by Pseudomonas aeruginosa. When wounds are deeper, the possible pathogens include anaerobes such as Bacteroides and Clostridium species.

A Hui Hou,
Steve

Kingetics- We Got Your Six...TM

 

Is that chapter or parts of it about online? here?

thank you

regards

ANdy

 

I've said in posts, here on the arena, much of what's in the chapter, however, it is not online.


Eric

 

Aloha,

This thread topic is barefoot vs. shod.

Who gets to decide what min and max shoes really are and what shoes belong to which group?

If we are making that decision on the basis of puncture protection where do dual density foam shoe systems belong? Where do hardened advanced composite shoes belong?

If we are making that decision on the basis biomechanical influence where does deforming EVA and PU foam shoes belong? Where do mechanical spring lever orthotics and advanced composite ankle foot orthoses belong?

If we are making that decision on the basis of energy efficiency where do collapsing foams belong? Where do high tensile strength advanced composite orthotic and shoe systems belong?

Mahalo,
Steve

[I]To be one, to be united is a great thing. But to respect the right to be different is maybe even greater.
[/I]Bono

 

Does anyone one know of any studies on the relation of thin soled shoes to metatarsal stress fractures. I recall finding a study/report of 11 or 12 subjects with injuries related to minimal shoes. Might have been the VFF's (Vibram Five Finger's). I think the report showed eight 2nd met stress fractures, 1 calcaneus stress fracture? Is this familiar to anyone? I don't remember where I saw this.

Also, is this a reliable or good study? http://www.acefitness.org/certifiednewsarticle/1641/

And finally, I went out and got myself a VFF and a Merrel trail glove. I couldn't help but note the extreme differences between the "minimal" products. Even between one VFF and the next VFF. One thing to note with these shoes is the "nobbie" pattern that makes up the out soles was transferred as significant mini hills and valleys within the shoe. Midsole cushion likely averages those little hills and valleys a bit. I know I make a habit in practice to stick my hand shoes and feel the area under where a person is complaining of pain. Especially if it is a met head. I would have to assume hills and valley's are not considered good features for met heads.

 

There is no good data except for the extreme number being seen by those who treat a lot of running injuries. Check these threads:
Injuries Observed in Minimalist Runners
Vibram FiveFingers Cause Metatarsal Stress Fractures?
Papers on Minimalist Shoe/Barefoot Running Injuries
Vibram Five Fingers and Plantar Plate Dysfunction
Vibram Five Fingers facing class action over health claims
Barefoot Running Injuries
Vibram Five Fingers study by American Council on Exercise
Another Metatarsal Stress Fracture from Vibram FiveFingers???
The Barefoot Running Injury Epidemic
Impact frequency data suggest unique risks for forefoot strikers
Impact parameters were significantly greater in the barefoot running
Increased Tibial Strain in Forefoot Striking

 

Does anyone one know of any studies on the relation of thin soled shoes to metatarsal stress fractures. I recall finding a study/report of 11 or 12 subjects with injuries related to minimal shoes. Might have been the VFF's (Vibram Five Finger's). I think the report showed eight 2nd met stress fractures, 1 calcaneus stress fracture? Is this familiar to anyone? I don't remember where I saw this.

Also, is this a reliable or good study? http://www.acefitness.org/certifiednewsarticle/1641/

And finally, I went out and got myself a VFF and a Merrel trail glove. I couldn't help but note the extreme differences between the "minimal" products. Even between one VFF and the next VFF. One thing to note with these shoes is the "nobbie" pattern that makes up the out soles was transferred as significant mini hills and valleys within the shoe. Midsole cushion likely averages those little hills and valleys a bit. I know I make a habit in practice to stick my hand shoes and feel the area under where a person is complaining of pain. Especially if it is a met head. I would have to assume hills and valley's are not considered good features for met heads.

 

Giuliani 2011, Leong-2010, Salzler 2011...
Juste receive the paper of Salzler and it's a retrospective case series ... not a very good study to bring conclusion that minimalist shoes are not good. Bias of selection, retrospective, people was doing transition between 0-2 month (half of people were doing a immediate switch)
The transition cane be safe if integrate gradually even barefoot!: Allison 2012(P)