Sort out your flat feet

I thought this was interesting: First Step Toward Treatment for Painful Flat Feet


It reports on a study which looks how flat feet in an adult occur:

Adult-acquired flat foot is most common in women over 40 and often goes undiagnosed. The condition results from the gradual 'stretching out' over time of a tendon near the ankle bone -- the tibialis posterior tendon -- which is the main stabiliser of the foot arch.

The researchers looked at the very structure of this tendon:

Working with surgeons and scientists at Addenbrooke's Hospital, Cambridge and the University of Bristol, the team showed that the structure and composition of tendon specimens had changed and found evidence of increased activity of some proteolytic enzymes. These enzymes can break down the constituents of the tibialis posterior tendon and weaken it -- causing the foot arch to fall.

The study itself is available here.  

What I found interesting though was the way the report skims over something important - the environmental factors......like footwear.  It mentions high heels as a risk, but I wonder if shoes in general also have an impact.  We dive into research into the structure of tendons that collapse.  Perhaps we just need more people barefoot or in simpler shoes. 

Free Your Feet: Why Running Shoes Do More Harm Than Good

Created by: X Ray Technician Schools

Fancy shoes injure you

Here is another one to support the barefoot guys.

An interesting piece on how basketball players who wear shoes with air filled cells building up the heels are more likely to get injured.

Basketball Sneakers, Ankle Sprains and Ankle Pains

Testing the Invisible Shoes (A Review)

I mentioned the other day that I'd been sent some Invisible Shoes to try.  Here is my review


Barefoot is best

Over the past few years on this blog I've often linked to pieces about the benefits of being barefoot.  Our feet are precisely engineered to support our motion, with an elegant arch to provide a great foundation for whatever we do.  Depending on your personal cosmology they have been designed - by God or evolution - to be the optimal solution, the best things that a biped could stand, walk and run on. 

It is not just the engineering either - our feet are full of receptors that feed information to the brain about our body's position in space giving data for your head to work with to keep you balanced and moving efficiently, an idea developed in Becoming Bulletproof.

Shoes interfere with all of this - they mess up the mechanics clamping the complex structures of the foot into a rigid brace and damp out all of the sensory information that should be flowing to your brain.  They ruin gait and lead to injuries.  Incidentally I'd say this goes double for stiff soled walking boots, but that is another argument.



Minimal shoes

I've been reading about this stuff for years now.  I remember reading Barefoot Ken Bob's site about 10 years ago and also reading Gordon Pirie's (free) book which while not explicitly barefoot promoted a style based on barefoot gait.

It has been interesting watching barefoot go mainstream recently prompted I suppose by Born to Run, but also by the recent scientific studies.  Of course as I've said before on this as on lots of other stuff, Phil Maffetone was way ahead of the crowd promoting barefoot or minimal shoes a long time ago in the Maffetone Method and Fix Your Feet.

Vibram Five Fingers also appeared - although for long enough I couldn't find any in my city.  More and more companies are now producing shoes that they claim are minimal or barefoot.  It has become a market....

Interestingly there is also the trend of writers out there saying that barefoot should mean barefoot, that even minimal shoes blunt the sensory data flowing from the feet.  mc covered this in her recent interviews with Mick Wilkinson.

Invisible Shoes

 Anyway enough of a preamble.  What about me?  Over the last few years I've moved more and more towards more minimal shoes - Chuck Taylors for most things, Inov8's for my hillwalking.  I even got a pair of Vibrams which I've been sprinting in.

Then a few weeks ago I was contacted by Gina from  Invisible  Shoes, offering me a pair of their running sandals to try out.  Never one to turn down a free sample (check out my other blog where I am testing stoves, tents and waterproof jackets!) I happily agreed.

After checking that there was no problem in them supplying to the UK, I had to tell them what I wanted:

• the 4mm “Connect”  thickness
• black laces

Then I had to give them the length of my foot so that they could supply the right size.

Within a week they arrived - two soles, two laces and a hair grip for threading the lace.   (The photo is in black and white - my feet looked too scary in colour.)

There area couple of things that you need to do for yourself with these shoes.

Create a toe hole - you need to mark a position on the shoe between your first two toes and make a small hole for the lace.  This really needs a leather punch, which I didn't have so I went to a local tailor and they made me the holes for free using the tool for punching holes in belts.

Lace them - then you need to lace the things.  It looks complex but is pretty simple - toe/ankle inside/ankle outside.  In any case there is a superb little video on the Invisible Shoes site which explains what to do.

I actually enjoyed the constructing of the shoes - it feels like you are really making them yourself.

Trying them out 


So that was it!  I've had them on all day today.  Walking about outside, driving to a country pub for lunch, playing in the garden.

It took a few tries to get a comfortable lacing but I am there now.  Also despite thinking that my gait was pretty good, being in things this minimal - they make the Vibrams feel excessive - really forces you to adopt an efficient gait with less heel strike.  Walking about on hard Edinburgh pavements you cannot let your feet get ahead of you, POSE style walking is needed and I was reverting to the ideas of Lee Saxby in his excellent book - Proprioception.  His key principles are:

•    Your weight should move from heel to big toe, but think of it more as a smooth heel stroke than a jolting heel strike;
•    Keep your strides shorter than normal – this will help keep your body in its optimum alignment for efficient locomotion;
•    Try not to look down; in fact, keep your gaze somewhere above the horizon and ‘lead’ with your chest;
•    Keep your stride relaxed, balanced and symmetrical.

Invisible Shoes in action

OK, this is me in the garden.  The video is only via the iPhone, but it gives an idea of me in the shoes walking and running (and please don't criticise my running gait too much!)



What do I think?

These are true minimal shoes.  If you have become interested in barefoot running or minimal shoes via Born to Run and the Tarahumara, these are as close to their footwear as you will get.  As I said, they make Vibram FiveFingers feel heavy and clumpy!  This is as Zero Drop as possible.

Invisible shoes are fun to make!  The construction of the shoes was part of the enjoyment - getting the hoel right, treading them and playing with the lacing.

Invisible shoes are cheap.  OK I got mine for nothing to review, but a kit for under $30 is great value.  Especially when I recently paid over £80 for my Vibrams.

Highly recommended if you want to get closer to truly being barefoot.


For info, here is their Press Release:

New Minimalist Running Sandal Corrects Stride and Heals Injuries : Invisible Shoes® Provide Healthy Option for Athletic and Casual Barefoot Footwear


Invisible Shoes® provide a true barefoot experience but with a layer of sole protection, allowing for complete natural movement, a lighter stride, foot strengthening and much more. Inspired by Christopher McDougall’s NYT bestseller, Born To Run, Steven Sashen created Invisible Shoes as a high-tech upgrade of the huarache running sandals that the Tarahumara Indians fashion out of used tires. Once he started wearing them, his chronic calf, knee and hamstring injuries quickly disappeared. Sashen then launched www.InvisibleShoe.com in November 2009, began selling Invisible Shoes online, and has since sold over 5,000 pairs in 35 different countries. On July 9th, 2011, Invisible Shoes launched the first and only outsoles specifically designed for barefoot running sandals -- the 4mm thick Connect and 6mm Contact. Both products were co-developed with two former lead designers from Nike and Reebok, and feature the exclusive FeelTrue™ rubber for a great barefoot feel with added style and protection.


Why Barefoot Running?


Empirical and anecdotal evidence shows that barefoot running improves running form, prevents and heals injuries, increases  balance and proprioception, improves posture, strengthens feet and ankles and can develop arches in previously flat feet. Research from Harvard’s Dr. Daniel Lieberman and orthopedic surgeon Dr. Joseph Froncioni shows that when wearing a typical padded motion control running shoe with a raised heel, runners land heel-first and with a relatively straight leg. This heel-strike landing sends a shock wave up to six times the body’s weight through the knees, legs, hips, back, shoulders and neck. Conversely, when running barefoot or in a minimalist shoe, runners land on the ball of the foot with a shorter, lighter, faster, easier stride which is cushioned by the body’s natural shock absorbers – muscles, ligaments and tendons. In short, research suggests running shoes are the very cause of the injuries they are supposed to prevent. With over 85 barefoot or minimalist footwear options on the market from over 20 different companies, minimalist running is being embraced by health and fitness-minded people around the globe. Industry analysts project that minimalist footwear will make up 10 percent of running shoe sales in 2011, $500 million of a $5 billion market.


The Invisible Shoes Story


Now injury-free and with arches in his life-long flat feet, at 49-year-old Invisible Shoes CEO Steven Sashen consistently sprints past runners half his age and has secured a spot as a USA Track & Field Masters All-American sprinter. The constant muscle pulls and tears in his calves and hamstrings, relentless burning pain in his posterior tibialis and throbbing knee pain that plagued him are distant memories.


Amazed that such a simple product could have such a dramatic effect, Sashen muses “I shouldn’t be surprised that mankind’s oldest footwear was the answer for running pain and injury-free.”


Invisible Shoes are perfect for running, walking, hiking, yoga, gym-going, or a casual stroll through town. While the average cost of other “natural movement” footwear is $99.82, built with up to a 12mm heel lift and weights of up to 12 ounces per shoe, Invisible Shoes start at $20, have a "zero drop" (no height difference between the front and rear of the shoe) and weigh in at 3.8 ounces per shoe. Comprised of high-performance, flexible FeelTrue™ rubber sole trimmed to perfectly fit your foot and durable, non-stretch nylon laces, Invisible Shoes let you enjoy a barefoot feel in any environment and on any surface. Customers can also feel good about their purchase because Invisible Shoes are made of partially recycled materials. Invisible Shoes also let you express yourself through your footwear, with colored lace options, numerous tying styles, and dozens of decorative add-ons, a la Crocs’ Jibbitz™.


Invisible Shoes Gives Back to the Tarahumara


To bring its Feel The World™ motto to life, Invisible Shoes donates 10 percent of the profits from its custom-made Invisible Shoes to the Tarahumara Children’s Hospital Fund.

Barefoot Training For Injury Prevention and Performance Enhancement

I have been browsing through the excellent website of the Boston Sports Medicine and Performance Group and there are some good resources there.

 This is a good presentation (pdf) on barefoot training

It is a good overview of the science and research.

Conclusions:

• Safety First : Evaluate and Educate
• It’s not for everyone
• Protect your feet : Minimal Shoes to start
• Slow and Steady wins the race (10% rule)
• Get Fit To Run, Don’ t Run To Get Fit
• Eliminate the high heels
• Be nice to your kids : wide toe boxes
• If you’re not injured, don’t change

I've mentioned a lot of this - like Lieberman's research - on this blog before

Focus on the Feet - barefoot is best

Steven Low has posted a great and exhaustive article on the feet.

A Firm Foundation: Focusing on the Feet


After some detailed analysis I like his conclusion:

Barefoot is the best solution we can do to help counteract atrophy of the feet. While if you have pain or worse symptoms then specific work may be needed, barefoot helps rebuild the feet especially if agility and balance work are incorporated effectively.

Blogging benefits - reviewing boots

I've probably said before that I have another blog which mainly chronicles my adventures on the hills - usually in the Scottish mountains.  It is just my record of days out really and a place for my photos.  Anyway I got my first real material benefit of being a blogger recently when I was sent a pair of walking boots to review.  Now I am really a minimalist footwear guy as you will have picked up from this blog but I was happy to get a free pair of boots to try on the hill.

Boots I was sent to review!

The review is here if you are interested. 

Barefoot is best for kids

Interesting article here in the Guardian: Some experts now believe that all shoes are best avoided in childhood

From a functional perspective, shoes shouldn't be necessary," says O'Neill. "In fact, there are more likely to be disadvantages and problems from wearing shoes than not wearing them - among them, deformation caused by a poor fit, ingrown toenails, and athlete's foot. But you have to consider the environment the child is in. Let's be honest. Do you want your child walking on the streets or in the park barefoot, where there might be dog poo, dirt and possible hazards like glass?"

Barefoot research

I spotted this on Drew Baye's Facebook:
THE WONDER OF THE BARE FOOT ON NATURALLY DEPOSITED GROUND and BETTER SHOES FOR MAN MADE CONDITIONS

A fascinating overview of research about the benefits of barefoot training.

Incidentally, the barefoot / minimalist shoe movement that the doctor complains about:

Running in both minimalist shoes and racing flats does not resemble barefoot running. If used on naturally deposited ground, the ideal condition for barefoot locomotion, these shoes essentially eliminate plantar surface (bottom of foot) localized deformations and shear stress, mechanical forces applied to the plantar surface which produce sensory feedback. These sensations are responsible for the mechanics of barefoot running. If used on outdoor man made surfaces, such as concrete and asphalt,, that allow minimal localized plantar deformation, these shoes will minimize shear stress thereby reducing sensory feedback to levels seen in any shoe.

....continues. I saw today that Merrell are bringing out a new line to cash in:

Merrell Goes Barefoot For 2011

We've saved the most interesting development till last, Merrell is launching a range of minimalist outdoor shoes called 'Barefoot' which they've developed in partnership with Vibram.

There are six models in the range – priced between £80 and £90 – all of which use the same Vibram sole unit with minimal support and cushioning. The theory, based on bare-foot running, is that removing cushioning and stiffening allows the foot to move more naturally and encourages forefoot striking rather than heel landing, which is only possible because of mid-sole cushioning.

Merrell says that the result is lower impact and a more efficient and aligned gait plus stimulated muscles increasing core strength, improving ability and building 'the body's ability to burn more calories'.

It's interesting stuff and the first barefoot shoes we've seen designed for general outdoors walking rather running. Intriguingly, the other advocate of minimal, barefoot footwear at the show was inov-8, arguably about as far away from Merrell as you can get.

Maybe I'm being cynical about cashing in. I like inov8 shoes though - a really nice fit that I use for the hills.

Barefoot Running - A Guide

Matt has pulled together a good page on barefoot running. Definitely worth a careful read.

The Evolutionary Correct Guide to Running

I am totally in agreement about some of these points, especially posture and walk breaks which are linked. I often see joggers run past with awful posture, bent over, shuffling along. To me one thing that stands out from them is that they do not look fit....they look by their very posture and stance to be damaged. Body language would mark them out as weak, and lacking in "pride" and confidence. They do not look like they could defend themselves. They look like prey....not hunters!

I want fitness to by accompanied by a stance that expresses health and confidence. The bent over shuffle doesn't do that. I'd rather people walked with confidence and pride than shuffled along looking tired and broken down.

If yo are too tired to run with decent posture and style then walk for a while!

Fancy shoes - don't bother

If you have ever bought running shoes from a specialist shop the assistants will likely have examined your foot and your gait and prescribed a particular style of shoe - motion control, cushioned or whatever....

Maybe it is all a waste of time and money! Chalk up another one for barefoot running.

Injury Reduction Effectiveness of Assigning Running Shoes Based on Plantar Shape in Marine Corps Basic Training

Abstract
BACKGROUND: Shoe manufacturers market motion control, stability, and cushioned shoes for plantar shapes defined as low, normal, and high, respectively. This assignment procedure is presumed to reduce injuries by compensating for differences in running mechanics. HYPOTHESIS: Assigning running shoes based on plantar shape will not reduce injury risk in Marine Corps basic training.
STUDY DESIGN: Randomized controlled clinical trial; Level of evidence, 1.
METHODS: After foot examinations, Marine Corps recruits in an experimental group (E: 408 men, 314 women) were provided motion control, stability, or cushioned shoes for plantar shapes indicative of low, medium, or high arches, respectively. A control group (C: 432 men, 257 women) received a stability shoe regardless of plantar shape. Injuries during the 12 weeks of training were determined from outpatient visits obtained from the Defense Medical Surveillance System. Other known injury risk factors (eg, fitness, smoking, prior physical activity) were obtained from a questionnaire, existing databases, or the training units.
RESULTS: Cox regression indicated little difference in injury risk between the E and C groups among men (hazard ratio [E/C] = 1.01; 95% confidence interval, 0.82-1.24) or women (hazard ratio [E/C] = 0.88; 95% confidence interval, 0.70-1.10).
CONCLUSION: This prospective study demonstrated that assigning shoes based on the shape of the plantar foot surface had little influence on injuries even after considering other injury risk factors.

barefoot is best for dodgy knees

So if you have osteoarthritis in your knees, you would be well advised to go barefoot or in minimal shoes... keep away from supportive, stable shoes with stiff soles.

Shoes: A treatment for osteoarthritis in the knees?

"Traditionally, footwear has been engineered to provide maximum support and comfort for the foot, with little attention paid to the biomechanical effects on the rest of the leg," said Dr. Najia Shakoor, a rheumatologist at Rush and the primary author of the study. "But the shoes we wear have a substantial impact on the load on the knee joints, particularly when we walk."

"Our study demonstrated that flat, flexible footwear significantly reduces the load on the knee joints compared with supportive, stable shoes with less flexible soles."

Osteoarthritis is the most common form of arthritis and a significant source of disability and impaired quality of life. A higher-than-normal load on the knees during walking is a hallmark of the disease, associated with both the severity of osteoarthritis and its progression.

barefoot is best again.....

The loads on the knee joints differed significantly depending on the footwear. For the clogs and stability shoes, the loads on the knee joints were up to 15 percent greater than with the flat walking shoes, flip-flops or barefoot walking. Knee loading was roughly the same whether the subject wore flips-flops or walked barefoot.

Barefoot Ted

I've previously pointed to the excellent book Born to Run, which looked at barefoot running within a narrative of a marathon in Mexico involving the Tarahumara Indians.

The book also features "Barefoot Ted" here he is talking to the Google Staff:

Barefoot professor

I referred to this study a few days ago (also here). Here is an interview with the professor.



From Nature:

Harvard professor Daniel Lieberman has ditched his trainers and started running barefoot. His research shows that barefoot runners, who tend to land on their forefoot, generate less impact shock than runners in sports shoes who land heel first. This makes barefoot running comfortable and could minimize running-related injuries. Read more here ... and find the original research here.

Snell on barefoot running

It is worth reading his blog about this

More on Barefoot Running

Further to the post from a couple of days ago on the latest research - How did we manage to run with no shoes ? - I was reading the excellent Science of Sport blog and they pointed to the page that the researches have set up to promote and give training tips for Running Barefoot or In Minimal Footwear

It is definitely worth reading - go here.

There are a couple of videos there that are worth looking at:

Forefoot Striking Barefoot: Produces Minimal Impact Force with No Impact Transient-



as compared to Heel Strike in Shoes: Produces Significant Impact Transient



There are some good tips for making the shift:

Tips on Transitioning to Forefoot or Midfoot Striking

Forefoot striking barefoot or in minimal footwear requires you to use muscles in your feet (mostly in the arch) that are probably very weak. Running this way also requires much more strength in your calf muscles than heel striking because these muscles must contract eccentrically (while lengthening) to ease the heel onto the ground following the landing. Novice forefoot and midfoot strikers typically experience tired feet, and very stiff, sore calf muscles. In addition, the Achilles tendon often gets very stiff. This is normal and eventually goes away, but you can do several things to make the transition successfully:

• Build up slowly! If you vigorously work out any weak muscles in your body, they will be sore and stiff. Your foot and calf muscles will be no exception. So please, don’t overdo it because you will probably injure yourself if you do too much too soon.
• Start by walking around barefoot frequently.
• First week: no more than a quarter mile to one mile every other day.
• Increase your distance by no more than 10% per week. This is not a hard and fast rule, but a general guide. If your muscles remain sore, do not increase your training. Take an extra day off or maintain your distance for another week.
• Stop and let your body heal if you experience pain. Sore, tired muscles are normal, but bone, joint, or soft-tissue pain is a signal of injury.
• Be patient and build gradually. It takes months to make the transition.
• If you are currently running a lot, you don’t need to drastically reduce your mileage. Instead, supplement forefoot or midfoot striking with running the way that you normally ran before beginning the transition. Over the course of several months, gradually increase the proportion of forefoot or midfoot striking and reduce the proportion of running in your old style. Use the same 10% per week guideline in increasing the amount of running you do forefoot striking.
• It is essential to stretch your calves and hamstrings carefully and regularly as you make the transition. Massage your calf muscles and arches frequently to break down scar tissue. This will help your muscles to heal and get stronger.
• Listen to your feet. Stop if your arches are hurting, if the top of your foot is hurting, or if anything else hurts! Sometimes arch and foot pain occurs from landing with your feet too far forward relative to your hips and having to point your toes too much. It can also occur from landing with too rigid a foot and not letting your heel drop gently.
• Many people who run very slowly find that forefoot striking actually makes them run a little faster.

Recap

• Land gently on your forefoot and gradually let the heel come down
• Transition slowly
• Stretch your calves and Achilles tendon
• Don’t do anything that causes pain
• Listen to your body and run totally barefoot to learn good form
• Buy minimal shoes that lack high heels and stiff soles
• Consult a doctor

How did we manage to run with no shoes?

Here is another one to think about in the "barefoot is best" category.

Scientists have found that those who run barefoot, or in minimal footwear, tend to avoid "heel-striking," and instead land on the ball of the foot or the middle of the foot. In so doing, these runners use the architecture of the foot and leg and some clever Newtonian physics to avoid hurtful and potentially damaging impacts, equivalent to two to three times body weight, that shod heel-strikers repeatedly experience.

Read more here (or in the LA Times here)

"Our hope is that an evolutionary medicine approach to running and sports injury can help people run better for longer and feel better while they do it," says Lieberman, who has created a web site, www.barefootrunning.fas.harvard.edu, to educate runners about the respective merits of shod and barefoot running."

Here is the summary in Nature:

Humans have engaged in endurance running for millions of years1, but the modern running shoe was not invented until the 1970s. For most of human evolutionary history, runners were either barefoot or wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning relative to modern running shoes. We wondered how runners coped with the impact caused by the foot colliding with the ground before the invention of the modern shoe. Here we show that habitually barefoot endurance runners often land on the fore-foot (fore-foot strike) before bringing down the heel, but they sometimes land with a flat foot (mid-foot strike) or, less often, on the heel (rear-foot strike). In contrast, habitually shod runners mostly rear-foot strike, facilitated by the elevated and cushioned heel of the modern running shoe. Kinematic and kinetic analyses show that even on hard surfaces, barefoot runners who fore-foot strike generate smaller collision forces than shod rear-foot strikers. This difference results primarily from a more plantarflexed foot at landing and more ankle compliance during impact, decreasing the effective mass of the body that collides with the ground. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.

Interestingly, the Open Water Chicago blog - a great read - commented on the story too and while agreeing with the barefoot bit, thinks that the case is not made for endurance running. Interesting in the light of this morning's post.

Be barefoot

I've often pointed to stuff in the past about the benefits of being barefoot (although I never write as well as mc on this or any topic)

Here is an extract of a good piece from the co-author of the Paleo Diet for Athlete's, Joe Friel:

I wish it was so easy as to say that we should all just run barefoot. Had we grown up like Kenyan kids - barefoot and running to school every day - we wouldn't need heavy-duty shoes at all. Our feet and legs would be strong and our technique would be excellent. Unfortunately, that simply isn't the case. We grow up wearing shoes as soon as the parents can dress the baby. I'm afraid the feet of most of us are not well-conditioned. But we can do something about that.

I think it might help if you got out of your shoes during the day whenever you can. I'm not talking about running shoes here, but rather your 'street' shoes. Taking them off around the house is a minimal but first step in strengthening your feet. Athletes who do this can progress to doing what I call 'barefoot strides' a couple of times a week. I start them off with doing 5-6 x 20 second sprints on a clean, grassy surface (with walk-back recoveries). If not ready for barefoot running try using a lightweight racing flat, Nike Frees, beach water shoes or Vibrams. The idea is to gradually do more walking and running with little or no footwear.

more on those shoes

further to the post from earlier this week on the evils of running shoes, two of my favourite bloggers have picked up on the story....with a lot more incisive comment and analysis than I managed to muster:


first of all mc: Running Shoes as Single Factor Thinking

This is a post about Shoes not as evil, but as it seems a Great Feat of Misdirection. It's a wee bit about our biases towards single factor solutions for complex problems, and the arguments we will have around the Chosen Factor rather than pulling up and back to consider the wider view.

Then Steven Low has updated his fascinating post: Shoes, Sitting and Lower Body Dysfunctions

It is a thorough analysis of how many of the common orthopedic problems today arise from shoes and sitting, how to evaluate their development, and finally a look at how to implement prehabilitation or rehabilitative protocol to improve their condition. I sincerely wish that you will read through the whole thing even though it is a monster. I promise you will come out with a new outlook on this topic.

Running Shoes are still bad!

I've had stuff up before on the damaging effects of running shoes and the benefits of being barefoot or at least in minimal shoes that let your feet function freely as they were designed to do.

Here is another interesting one to consider:

The Effect of Running Shoes on Lower Extremity Joint Torques (the full text is available)

Results

Increased joint torques at the hip, knee, and ankle were observed with running shoes compared with running barefoot. Disproportionately large increases were observed in the hip internal rotation torque and in the knee flexion and knee varus torques. An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.

There is a good commentary on this here: Running shoes may cause damage to knees, hips and ankles

These findings confirm that while the typical construction of modern-day running shoes provides good support and protection of the foot itself, one negative effect is the increased stress on each of the 3 lower extremity joints. These increases are likely caused in large part by an elevated heel and increased material under the medial arch, both characteristic of today's running shoes.

Writing in the article, lead author D. Casey Kerrigan, MD, JKM Technologies LLC, Charlottesville, VA, and co-investigators state, "Remarkably, the effect of running shoes on knee joint torques during running (36%-38% increase) that the authors observed here is even greater than the effect that was reported earlier of high-heeled shoes during walking (20%-26% increase). Considering that lower extremity joint loading is of a significantly greater magnitude during running than is experienced during walking, the current findings indeed represent substantial biomechanical changes." Dr. Kerrigan concludes, "Reducing joint torques with footwear completely to that of barefoot running, while providing meaningful footwear functions, especially compliance, should be the goal of new footwear designs."

Amazing that running shoes are worse than high heels. Also it sounds like he needs to look at some Vibram Five fingers!


Hat tip to Mark Sisson for the video who was nice enough to give me some link love today.