Biomechanics used in the design process

Hey guys long time reader first time poster.


Basically my background is working for the largest Sports retailer in Australia as the technical footwear trainer.

I teach all staff about the biomechnics of the human lower body and overall technology’s of all brands and suppliers.

I am an kind of like an EKIN for all brands.


The question I have is what influence to the biomechanists have on the design process? I know there are a few guys here who work for the big suppliers.

So basically do you design based on existing technologies and biomechanic principles or do you work directly with biomechanists to design the new technology?

I have seen alot of feedback coments to newer designers about thinking about where the company is headed and thinking outside of the box.

How much of that is done in the true brand designs that make it to the shelf?

I have been exposed to some of the Asics design process as one of the head designers is based in Australia along with the podiatrist who consults for them and from what I understand it is kind of a 2 part process.

Just wanted to hear your thoughts on this.

cheers

Steve

work with the NSRL all the time to develop better ways to improve the foot/shoe/ground dynamic relationship:

http://www.nike.com/nikebiz/nikebiz.jhtml?page=6&item=research

Yo, thanks for the response.

in your case is it a matter of the deign process working around the research or is the research imputed after a rough asthetic design?
or is it a case by case basis for each model?

It’s a bit more collaborative. The designs we work on together are focused on concept and function. Ideas will be generated, samples then tested. The testing provides data that leads to totally different ideas. After a bunch of go rounds, the design evolves.

Hi jugglie

I can answer your question from the perspective of a doctor and running shoe researcher independent of the big manufacturers.

As far as published literature goes, I am not aware of any trials which have actually tested the impact of a running shoes on either injury rates or running perfromance was actually tested.

Even the biomechanical studies really don’t support the standard running shoe design of an elevated cushioned heel with motion control features tailored to an individuals foot type.

Current running shoe design is based on theories proposed in the late 70s and early 80s which made sense but didn’t stand up when systematically tested.

If you would like a great introduction to the topic, read this article written by an orthopaedic surgeon http://www.quickswood.com/my_weblog/2006/08/athletic_footwe.html

I am also based in Australia (Newcastle) and would be happy to talk to you in more detail if you would like.

Hi Craig,

There have been no real studies (public) on the effect of footwear on injuries as it is so hard to control, injuries are typically multi factorial + subject size you would need + controlled environment (there is a lifetime research project for someone.

There have been tests on running performance such as high gear vs low gear. If you can push the foot into high gear then you can get quicker running times, I have seen this theory proven but with only a one subject!

It is not true that current shoe designs are based on 70-80 theories only although most of these, ie Cavanagh are true to today, relevant and apply.


Biomechanics in design is hugely relevant although you need to know what you want to achieve apposed to just reading a paper and using that theory in design. You need to understand the mechanics of the individual sport first.

what needs to be remembered is that in any foot size there a 9 variants of foot type. This is the first issue and the second is then how does this translate to a level where the consumer gets it without podiatrists and the product costing $400.00

With customisation becoming a key part of the consumer experience and people purchasing for the logic of utility apposed to only desire you will begin to see products evolve more biomech influenced.

The big problem is that what could be correct for you might be wrong for me.

I would like to pose two questions to the forum:

  1. how many designers feel they have a solid grounding in the science behind running shoe design?

and

  1. do you consider that the features you currently use in your distance running shoe are evidence based ie have they a)been shown to achieve the desired change in biomechanics in lab studies and then b) been shown to decrease injury rates or performance in clinical trials?

Hi Craig

I’m also more a reader that poster.

I have to say I discovered this forum searching more information on athletic shoes investigation and design, soon discovered the process nowadays has large influence from marketing departments and little from real investigation.

I’m a little disappointed, but like to read most of wat is discussed here annyway.

I will finish by telling you a little episode:

Last year I attended a lecture by the investigation lab director from one of the big athletic brands, and after a few questions I returned home disappointed, thinking to myself:

“They are always speaking about professional athletes and how they work with them to develop products, what about the average Joe that really spends his money in their products?”

“They are so focused in technologies and materials that forget about Fit or foot function, looks like they never had to fit a pair of shoes in their life”

From my perspective I feel I have an excellent grounding in biomechanics and work in partnership with Trevor Prior, one of this countries leading podiatrists and an expert on sports biomechanics.

With regards to our designs, they are purely born out of clinical evaluation (i deal with soccer footwear) and focus on things such as heel height, control (orthotics) degree of flex, direction of flex, stud placement dependent on loading and foot structure and so on.

With regards to injuries, as stated before, how can this ever be evaluated?

On another note, the reason I focus on elite athletes and then take to the mass market is due to the fact that these guys and girls use the product day in and day out. They have a clear idea on what they want BUT not what they need. It is my job to create the perfect balance of want and need = form and function

A very confident answer bespoke, which is undertsandable given the expert input you receive.

As a general point to readers, I would point out that the majority of training podiatrists receive is not evidence based, so unless you are working with an academic podiatrist actively engaged in research, the advice you are being given may not in fact be correct.

That said, you have raised a number of issues which perhaps we could explore.

Firstly, what is the biomechanical effect you are trying to achieve by altering heel height? How do you expect this to impact on performance or injury risk?

Secondly, are you aware that orthotics can have the opposite effect on alignment to that which is intended?

Thirdly, if no attempt is made to measure the impact of footwear design on injury rates, how will we ever know if our designs are in fact making things worse?

Craig, firstly these written documents come across very 2-dimensional and I read what you say below as more of an open discussion.

  1. Trevor Prior is chair of the podiatry association, works with Chelsea, Arsenal, Tottenham, West Ham, Manchester City just to mention a few clubs as well as UK Athletics, Formula 1 etc. He has carries out lots of research which you will find if you have access to publications.

Readers should note podiatrists are like any other profession, you get good and bad ones, ones who are interested and enthused by their job others less so.

Heel height has two effects, 1 leg length issues…2 brings contact to the ground quicker as soccer outsoles are typically flat…I am sure you aware of the effects of flat footwear in soccer, Achilles etc…

An orthotic is only as good as the person prescribing, we test our orthotics in a number of ways including using in-shoe pressure analysis within an inhouse protocol.

I agree with your third point but someone needs to develop the protocol, how would you measure this is a sport like soccer full of multi factorials? If you have the answers I would like to know. I could do this but how do you get 92 professional clubs to take part in a controlled analysis when training and athletes are so uncontrollable?

The best way to test the impact of a new shoe design on injury rates is as you say with a large cohort of athletes who are randomly assigned to two groups. This doesn’t mean that the athletes in a test group necessarily wear identical shoes, for example one group might wear shoes with heel raises and inserts individualised to foot type (whilst the other group wears standard shoes without these additional features).

What has to be measured in these studies is the impact on both overall injury rate and performance. Heel raises may in fact decrease achilles injury rates but for example at the cost of decreased top end speed and increased ankle sprains or knee injuries.

Please look in http://www.footwearbiomechanics.org/ the

2009 Nike Award Guidelines

The topic for the competition will be the role of athletic footwear in the prevention of sport injuries

Craig,

I am still struggling with the notion of how we pick out the injury. The FA audit all injuries and the boots are a factor but how do we determine if it was condition, boot, contact etc. I want to understand how we pull that picture apart and assess where and if the boot is to blame vs the way they knit pitches together as an example.


On the comment about heel raises, everything you do with footwear has an impact on something else, what is right for one person is wrong for another. This is where the footwear designer gets a bit of an unfair bashing, whatever they try to innovate can be spun as something bad for the athlete. Yes there are some terrible products out but there are also some which are not all bad.

To test the theory maybe we should run a pilot project together, it would be the only way to answer the questions!

Sounds interesting- what elements define your protocol for boot prescription? What is an alternate approach that is commonly used that you would test yourself against? A simple and interesting comparator would be boot choice based on players perception of comfort rather than biomechanical analysis. There is certainly some data to suggest that for orthotics comfort is an effective predictor of the effectiveness of an orthotic’s effect on allignment.

Controlling for other variables is not of great concern as long as the randomisatioon process is effective. Sports shoes are just another therapeutic intervention and as such their impact can be assessed in spite of the presence of large number of other factors which effect the end outcome. Randomisation results in equal numbers of players in each trial group being exposed to these other factors eg number playing on dodgy pitches,being exposed to illegal tackles etc. As such, their effect is equal in each group, cancelling out their capacity to alter the result. This is how drug companies assess the effectiveness of drugs such as cholesterol medications- clearly there are a large number of factors which can cause heart attack and they want to know if their drug does in fact have a beneficial effect on the rates of heart attack. Of course these trials need to be large and can be expensive to run. This cost restricts the rate at which new medications enter the market and in the same way the need to properly assess the safety of footwear will slow the rate at which new designs can enter the market. This will be a drag for designers because their creativity will exceed the capacity of the industry to dedicate resources to testing the safety of new designs. However, it will mean a safer product and clear guidelines for designers to work within.

Thanks for the tip re the Nike award Paulo- looks like a good one to work towards.

I would rather keep my protocol under wraps for obvious reasons. The problem I have with the comfort test is that it depends upon verbal feedback. Asking the question of how does that feel. I prefer to test for fit, which is a big part of comfort and use methods such as 3D data capture not relying on the athlete to tell me. He/she knows what they want but not what they need. For me, I really want to understand what is good fit for the athlete then mass population. Foot types etc all considered

The study issue also comes down to ethics and the current set up deters most designers away. The document for ethical clearance in the UK is enormous and uses language and terminology that is tricky to understand if not from the medical world.

It is all very well the study variables being constant enough, but how do you define at the point of injury the cause of that injury. e.g. cleat looks into turf as player brakes and knee injury occurs, is it the stud, the turf because he was on the part of pitch that was knitted together or the way the turf grows, the fact he was pushed whilst planting his foot.

Yep good point. Randomised controlled trials are still the first step. These are used to define the total effect of the design/design approach on the rates and pattern of injury compared to the established gold standard. Once this is known, it will be clear where the strengths and weaknesses of the design are. Once this is known you can then use specific biomechanical analysis to define the source of the problem eg excessive ACL injury rates and test solutions. However, once you think you have improved the design, you then have to go back to randomised controlled trials to ensure not only that have you decreased the rates of ACL injury, but you have also not inadvertently increased the rates of other serious injuries.

Ethics is not a great problem, you just need to approach a local university department to find out who might be interested in testing your theories. Another approach would be to find who is authoring papers in your area of interest and contact them directly.

If anyone has running shoe designs they are interested in testing they are welcome to contact me for further advice.

One very big word of caution when using universities, get a water tight agreement that they will not seek further DTI or Government funding to take your concept further without you working with them. This has happened to me with two separate Uni’s-admittedly I was a little younger then and less experienced in the business sense. Many lecturers have spin out companies and can use university resource to plug back into those companies at 50% less commercial rates. Secondly they survive on telling a story to receive more funding so your concept (even sometimes with an NDA) will be talked about. This again happened to me seeing my work turn up in a published paper in Japan just to mention one instant.

On the flip side, the problem with using test houses geared for footwear is that they try to be neutral as they want to work for all footwear brands. It does not look good for them if you publish research that shows Adi shoe vs a New Balance shoe if the results clearly indicate one shoe as a better performa.

I have found individuals with a keen interest and high level understanding is the way forwards. Craig, you seem to potentially be one of those! Are you independent or affiliated to a larger company?

I remain untainted :slight_smile: