Can Minimalist Shoes Be Beneficial For Osteoarthritis-Related Knee Pain?

Nicholas A Campitelli DPM FACFAS

A new study accepted for publication in Arthritis & Rheumatism says patients walking barefoot or wearing minimalist shoes have reported a reduction in knee adduction as well as reduced pain.1 This article is greatly needed in the world of orthopedics where the majority of orthopedists are still prescribing foot orthotics to treat many of the lower extremity injuries that do not warrant surgery.

Despite the fact that literature does not support the use of foot orthotics for conditions such as plantar fasciitis, shin splints, knee pain, iliotibial band syndrome, piriformis syndrome and many other running injuries, an overwhelming number of physicians and healthcare providers implement orthoses in their practice.

For years, physicians prescribed orthotics to prevent excessive pronation, which they thought to be a biomechanical fault in individuals leading to injuries. This continues to be an indication for use although excessive pronation is not as detrimental as we once thought. Many times it becomes nothing more than convenience for a physician to prescribe an orthotic for a patient with unexplained foot pain. In my practice, these patients tend to show up with bags of shoes and orthotics with continued pain.

The Arthritis & Rheumatism article acknowledges that current studies have demonstrated that both barefoot walking and walking in a minimalist shoe is associated with reductions in knee loading in comparison to conventional footwear. The primary focus of this particular study was to demonstrate a reduction in force to the medial knee as well as decreased symptoms of knee osteoarthritis over a longer period of time, which in this case was six months.1 The study authors looked at the peak external knee adduction moment and the adduction angular impulse. Both parameters reflect the extent of medial compartment knee loading during walking. The results demonstrated an 18 percent reduction of the force to the medial knee as well as a reduction in pain of 36 percent.

This is extremely significant because of its follow-up time combined with previous research that demonstrates decreased force to the knee joints as well as pain as a result of functioning in less of a shoe. A previous study from 2012 showed similar results with minimalist footwear, demonstrating decreased force to the knee joints and reduced knee pain.2

It will take time to see the effects of these studies make their way to actual medical practices, especially the orthopedic and podiatric specialties that focus more on surgical therapy than “running form” and “technique.”

Remember that for the past 40 years or so, podiatrists have believed in and recommended countless amounts of orthotic devices to their patients. They have also taught this philosophy to students and residents. We have seen the evolution of industries in which the primary focus is manufacturing foot orthotics that are custom made for the patient’s feet. It has become commonplace for specialty shoe stores to recommend over-the-counter inserts as an adjunct to the traditional running shoe they sell to their customers. Our society has accepted that we need to support our feet and arches.

While it may take time, I believe we will see a gradual change from supportive running shoes and orthotic devices to more minimalist style footwear. However, the change is beginning as is evident by the focus of current research as well as the evolution of more minimalist shoe gear. Over the past several years, heel height in shoes manufactured by Saucony and New Balance has decreased from an average of 12 mm to 8 mm. More than likely, the change is going to occur in the running and shoe industry first before it makes its way to the medical community.

References

1. Shakoor N, Lidtke RH, Wimmer MA, et al. Improvement in knee loading after use of specialized footwear for knee osteoarthritis: Results of a 6-month pilot investigation. Arthritis Rheum. 2013 Apr 10. Epub ahead of print.

2. Trombini-Souza F, Fuller R, Matias A, et al. Effectiveness of a long-term use of a minimalist footwear versus habitual shoe on pain, function and mechanical loads in knee osteoarthritis: a randomized controlled trial. BMC Musculoskelet Disord. 2012 Jul 12;13:121.

Editor’s note: Dr. Campitelli has disclosed that he is an unpaid Medical Advisor to Vibram USA.

Comments

Kevin A. Kirby DPM's picture

Dr. Campitelli shows that, in his blog on minimalist shoes and knee pain, that he doesn't really like to do any research or literature review on a subject before he likes to give his opinions. Rather, Dr. Campitelli only seems to be concerned with spreading the “barefoot-minimalist shoes will cure everything and thick soled shoes and orthotics are bad” message to anyone who will listen.

Let's look at just one point of Dr. Campitelli’s blog and show how ridiculous this statement is.

Dr. Campitelli wrote: “Despite the fact that literature does not support the use of foot orthotics for conditions such as plantar fasciitis, shin splints, knee pain, iliotibial band syndrome, piriformis syndrome and many other running injuries, an overwhelming number of physicians and healthcare providers implement orthoses in their practice.”

What are you talking about Dr. Campitelli? Don’t you ever read any literature other than those that promote barefoot running and minimalist shoes? If you would take the time to read the scientific literature, and not just cherry-pick the few research articles that support your opinions, you would understand that there are a number of research articles that support the use of foot orthosis therapy.

Let’s look at the facts on the research evidence regarding foot orthosis therapy.

Scientific research showing a positive therapeutic effect from foot orthoses:

Donnatelli R, Hurlbert C, et al. Biomechanical foot orthotics: A retrospective study. J Ortho Sp Phys Ther, 1988;10:205-212.
Gross ML, Davlin LB, Evanski PM. Effectiveness of orthotic shoe inserts in the long distance runner. Am. J. Sports Med. 1991;19:409-412.
Saxena A, Haddad J. The effect of foot orthoses on patellofemoral pain syndrome. JAPMA. 2003;93:264-271.
Blake RL, Denton JA. Functional foot orthoses for athletic injuries: A retrospective study. J. Am. Pod. Med. Assoc. 1985;75:359-362.
Moraros J, Hodge W. Orthotic survey: Preliminary results. JAPMA. 1993;83:139-148.
Gross MT et al. The impact of custom semi-rigid foot orthotics on pain and disability for individuals with plantar fasciitis. J Ortho Sp Phys Ther. 2002;32:149-157.
Walter JH, Ng G, Stoitz JJ. A patient satisfaction survey on prescription custom-molded foot orthoses. JAPMA. 2004;94:363-367.

Scientific research showing success rate with custom foot orthoses in treatment of running injuries is 50-90 percent:

Eggold JF. Orthotics in the prevention of runner’s overuse injuries. Phys. Sports Med. 1981; 9:181-185.
D’Ambrosia RD. Orthotic devices in running injuries. Clin. Sports Med. 1985;4:611-618.
Dugan RC, D’Ambrosia RD. The effect of orthotics on the treatment of selected running injuries. Foot Ankle. 1986;6:313.
Kilmartin TE, Wallace WA. The scientific basis for the use of biomechanical foot orthoses in the treatment of lower limb sports injuries-a review of the literature. Br. J. Sports Med. 1994;28:180-184.
Shih YF, Wen YK, Chen WY. Application of wedged foot orthosis effectively reduces pain in runners with pronated foot: A randomized clinical study. Clin Rehab, 25(10):913-923, 2011.
Ferrari R. A cohort-controlled trial of customized foot orthotics in trochanteric bursitis. J Prosth Orthotics, 2012;24(3):107-110.

Research from large (n=400) military prospective study showing decrease in injury rate with foot orthoses with a 10 time reduction in medial tibial stress syndrome and a 7 time reduction in chronic exertional compartment syndrome with foot orthoses.

Franklyn-Miller A, Wilson C, Bilzon J, McCrory P. Foot orthoses in the prevention of injury in initial military training. A randomized controlled trial. Am J Sports Med. 2011; 39:30-37.

Prospective research (n = 179) showing foot orthoses are effective in treating patellofemoral pain syndrome:

Collins N, Crossley K et al. Foot orthoses and physiotherapy in the treatment of patellofemoral pain syndrome: randomised clinical trial. Br J Sports Med. 2009; 43:169-171.

Randomized control trial (n = 40) showing foot orthoses produced significant improvement in symptoms and function in treating anterior knee pain versus wait and see approach:

Mills K et al. A randomised control trial of short term efficacy of in-shoe foot orthoses compared with a wait and see policy for anterior knee pain and the role of foot mobility. Br J Sports Med. 2011;46:247-252.

Research showing foot orthoses are effective in treating trochanteric bursitis of hip:

Ferrari R. A cohort-controlled trial of customized foot orthotics in trochanteric bursitis. J Prosth Orthotics, 2012;24(3):107-110.

Scientific prospective research from military showing orthoses reduce incidence of stress fractures in military recruits:

Finestone A, Giladi M, Elad H, et al. Prevention of stress fractures using custom biomechanical shoe orthoses. Clin Orth Rel Research. 1999;360:182-190.
Simkin A, Leichter I, Giladi M, et al. Combined effect of foot arch structure and an orthotic device on stress fractures. Foot Ankle.1989;10:25-29.

These are just a few of the references that show that Dr. Campitelli obviously doesn't want to take any extra time doing a literature review when he writes his opinions. My suggestion to Dr. Campitelli is that before he make claims and writes an article that everyone can see, he first takes the time to do some research on the subject.

I guess I'm a little more progressive thinking in my approach to treating running injuries. In my generation of training, we focused on evidence-based medicine with respect to all aspects of medicine including and not limited to surgery, medicines and even therapies. With respect to orthotics, it is pretty well accepted in today's age of medicine that they may be helpful as a short-term solution, preventing injuries in some athletes.

However, it is not clear how to make these devices work from a systematic and evidence-based approach. The idea that they are supposed to correct mechanical-alignment problems does not hold up in current literature. When it comes to controlling pathologic subtalar joint motion, then an ankle foot orthoses or arthrodesis is indicated, not a shoe or foot orthotic.

It is also pretty clear that using an foot orthotic in someone who heel strikes in with an outstretched leg is avoiding the root of the problem which lies in addressing the form, not the foot.

Dr. Nick

Kevin A. Kirby DPM's picture

Dr. Campitelli seems to now have changed his tune since he has been challenged by his ignorance or his purposeful disregard for the research evidence that clearly shows that foot orthoses are not only therapeutic but also can positively alter the kinetics and kinematics of gait.

First, Dr. Campitelli says:

"Despite the fact that literature does not support the use of foot orthotics for conditions such as plantar fasciitis, shin splints, knee pain, iliotibial band syndrome, piriformis syndrome and many other running injuries, an overwhelming number of physicians and healthcare providers implement orthoses in their practice."

Then he now changes his mind and and says:

"With respect to orthotics, it is pretty well accepted in today's age of medicine that they may be helpful as a short-term solution, preventing injuries in some athletes. "

So, Dr. Campitelli, does the literature support the use of foot orthotics for many foot and lower extremity conditions that are mechanically-based or not? Which one is it?

Just forget about long-term or short-term use. Just answer the question. We are all becoming confused by your words and your apparent flip-flop on this important issue.

Actually, I'd rather hear about the short-term vs. the long term solution. Short-term solutions aren't going to do me much good. In that sense, it seems Dr. Campitelli is being consistent. Foot orthotics might help short term but if the subject continues to use bad form, than long-term, there will be bigger problems.

Well put Dan. I too and certainly my patients are interested about long-term outcomes, and NOT short-term benefits.

Sorry, Dr. Nick, but your bias is showing. You are against anything other then a minimalist view of biomechanics. You continue to be on the fringe of modern podiatric biomechanics, shunning the solid scientific base of the modern structured running shoe, and the gold standard for treating many foot and ankle conditions by the use of functional foot orthotics to correct abnormal biomechanics. You are not being "progressive." You are just being contrary to get noticed. You use words like "evidence-based" but ignore the actual science.

The root problem here is you set your course, put on your blinders and continue to stumble over the science. You seem to be on some sort of ego trip. What else could be behind your unwillingness to recognize the science? The last thing we need is "voodoo medicine"!

Dr. Bob

If "progressive thinking" means ignoring the evidence except when it suits, if "my generation of training" means that the ability to apply evidenced-based practice is restricted to "cherry picking" the literature that supports your contention, that "within your generation," the understanding of the pathogenesis of biomechanically related problems is limited to deviations from a normal posture, and the understanding of how foot orthoses work is nothing better than "by realigning the posture" as reflected in the comments made by Dr. Campitelli, then I truly fear for the future of podiatric biomechanics education within the United States.

I had heard that biomechanics was taking a back seat in the States but actually blog posts such as this present a dawning realization as to how far behind some of you must now be lagging. Y'all might want to look at what has been happening in podiatric biomechanics outside of the USA in the last 20 years.

Well put Simon. Some of these dingos won't know biomechanics of it bit them in the $&@$. Calling the evidence available on orthoses as "solid" and referring to it as the gold standard is worrying. I have podiatrists conning patients that they are conducting a "biomechanics" assessment while observing patients walk up and down dimly lit corridors, and observation only in frontal plane. Hey guys, wake-up! You are not doing a BMX assessment, far from it and certainly left behind. I am a progressive podiatrist! I combine technique and precision (digital EMG, 3D ISU sensors, pressure analysis & opto-gait), and for the record, I have not prescribed customised orthoses since 2010. I use some OTC insole on occasion. I address muscular issues occurring at the various regions (ie foot, pelvic girdle etc.). Far better results with long-term survival of Tx benefits. Yes, I am interested in the long term benefits.

As for selectively choosing articles, this was a blog post reviewing a specific piece of literature supporting the use of minimalist shoes in treating OA of the knees. I was simply trying to spread the word on some progressive studies that are of today's era, not those of which are 20 or more years old.

Hello Dr. Campitelli,

Great article. I'm a guy with bags of shoes and orthotics but I still have sore feet.

I came across a new shoe from Switzerland (http://www.kybun.com/products-and-stores/kybun-products/kyboot.html ) that has a very flexible sole, is light and creates the feeling of walking on soft soil with up to an inch of springy polyurethane. You could say they are minimalist shoes with lots of padding. The inventor claims that this shoe requires greater movement in the foot and as a result will strengthen foot/calf muscles, tendons and ligaments.

I have had plantar fascitis for almost ten years. The pain has spread to both Achilles, a knee, a hip and my lower back.

I ordered a pair and will be getting them soon.

I would like to know your thoughts on this type of shoe please.

Thank you,

John Kenyon

I concur with Professor Kirby's comments. Dr. Campitelli is either ignorant of the literature or is purposively ignoring it.

Further, when one has an understanding of biomechanics and hears statements such as "(patients) wearing minimalist shoes have reported a reduction in knee adduction," we should be cognizant that one could equally state that "wearing minimalist shoes increases knee abduction moment" since it is a zero net game, and there really is no such thing as a free lunch. In decreasing the loading from one tissue, you will increase the loading on another. It's a case of picking the right horse for the right course. In decreasing the force to the medial knee, you've usually increased the force to the lateral knee.

P.S. To expand upon my "horses for courses" comment: would I prescribe a varus posted foot orthosis for a patient with medial compartment osteoarthritis (O/A) of the knee? No, since this would increase the knee abduction moment. Would I prescribe a valgus wedged foot orthosis for this patient? Yes, because there is good evidence that valgus posted insoles are helpful in medial knee O/A. I wonder if Dr Campitelli is familiar with this literature?

I live in the United Kingdom. The majority of my patients with medial knee O/A don't want to go barefoot or wear "toe shoes" that make them look like a clown. In their minds, and mine too, the best conservative option for medial knee osteoarthritis is a well designed shoe insert.

At Root Laboratory, we periodically receive Rohadur functional foot orthoses for reposting of the rearfoot from some of Dr. Root’s own patients. Given that Dr. Root retired from practice in the mid-1970s, I was wondering what Dr. Campitelli means by short term when he says “With respect to orthotics, it is pretty well accepted in today's age of medicine that they may be helpful as a short-term solution, preventing injuries in some athletes." Many of the devices I’m referring to are well over 30 years old! Symptom free after 30 years seems like an excellent “short term” solution to me.

Jeff Root
President, Root Laboratory, Inc.

One of the worse parts of this article is it displays the cherry picking of someone out to promote an agenda rather than takes all views on an issue (as Dr Kirby has already pointed out).

The reference number two cited was only the protocol to the study which the results are not even available! How can you make the conclusion about the results of the study when they are not even available?

The published research also shows that increased shock absorption also helps knee OA. Any reason you did not include references to that research? Or does that not fit in with your agenda?

Oh dear ... one of the few disadvantages of living in the great Southern land is that occasionally one must wake up to this sort of drivel.

Nick Campitelli, DPM, is once more pushing his Vibram sponsored barrow to manipulate the current science in his own image.

What he espouses in his article has been well known for many years. Shakoor et al have been investigating this issue for at least seven years and long ago established that ambulating barefoot compared to self selected footwear increased the external knee adduction moment (EKAM) of the knee. That is hardly a surprise but man is Nick only telling a tiny part of the story here, and neglecting the fact that in ALL these studies, the research cohort was elderly (6th decade and beyond), often had major biomecahnical issues such as flagrant tibial varum secondary to meniscectomy, were often overweight, and had to have chronic knee pain and established degenerative joint disease to be included in the study.

Campitelli then makes the gigantic and breathtaking leap of faith from this aged, overweight, biomechanically challenged, OA with pain population to the athlete and world of sports medicine, saying we will see a change from "supportive running shoes and orthotic devices to more minimalist style footwear" and espousing the benefits of minimalist footwear from Saucony and NB.

He goes on to say the running shoe industry will drive changes to make footwear more minimalist, but still fails to establish the connect between an aged, overweight, degenerative, in pain, biomechanically corrupt population with the athlete.

The thing that concerns me most about his diatribe is the ongoing bias he has and his ignorance of the science. This has been covered by other contributors above but does he even understand moments? If he does, he would know that they cannot be created or destroyed, only shifted. He alludes that by wearing a minimalist shoe ... say a Vibram Five Fingers for instance ... or going barefoot, that the knee loading will decrease and that global wellbeing will follow. Hmm ... .

Well, it is true that by wearing a minimalist shoe or going barefoot, the EKAM may well be reduced by a relatively small amount BUT he fails to mention that there will be a LARGE increase in the external ankle joint moments, resulting in a large increase in loading at the Achilles tendon and plantar fascia. This is the reason Vibram is the only footwear manufacturer in the world to issue a 15 page manual on how to wear its product (VFF). Even when the prescribed online manual is followed to the T, a recent study showed 10 out of 19 subjects developed frank signs of bone injury wearing the product, including two who developed frank stress fracture, including a calcaneal stress fracture! (Foot Bone Marrow Edema after 10-week Transition to Minimalist Running Shoes.Med Sci Sports Exerc. 2013 Feb 22. [Epub ahead of print] Ridge ST, Johnson AW, Mitchell UH, Hunter I, Robinson E, Rich BS, Brown SD.)

Every clinician intimately involved in the treatment of athletes understands there is no one true way Nick. Every educated practitioner understands the role of more flexible footwear or even barefoot training as a part of a balanced training program. Far from your assertion that there is an ongoing trend toward minimalist footwear, the reverse is true and the sales of such products globally, and in the USA especiall, are on a rapid decline. You can only fool the people for so long Nick ... then they get injured.

Finally, I would like to comment on your remark "I guess I'm a little more progressive thinking in my approach to treating running injuries. In my generation of training, we focused on evidence-based medicine." This reeks of delusions of grandeur and more disturbingly suggests that your "generation of training" is superior to those of previous generations. The blog you have submitted is in no way is evidence-based, quite the contrary. And you are crossing swords with the likes of Drs. Spooner, Kirby and Payne, who long, long ago made the transition from the somewhat theoretical world of podiatric biomechanics, which still holds tremendous value, to the unforgiving world of applied and clinical biomechanics. This is an unforgiving terrain Nick and if you wish to enter this world, you better know your stuff. Based on your comments above, I think you have a long way to go.

The modern structured running shoe is an oxymoron. Our foot was designed to be mobile and absorb shock. It is simple physics. We’ve known that for many years. There is no logic behind placing a rigid device into a shoe to reduce shock absorptive capabilities. Remember, I’m referring to those who can walk and run. If someone has a pathologic foot, then by all means, brace it. Runners do not have pathologic deformities. If they do, they would not be running.

As for the work of Root. I’m sure it has brought us to where we are in today’s field of biomechanics but it is no longer accepted as the gold standard. Times have changed and medicine and thinking have progressed. Had they not, we would still be practicing third-world medicine. Just because something was accepted 40 years ago doesn’t make it right today.

The literature is definitely not conclusive in regards to treating foot disorders with orthotics. I have not changed my mind on any of my thinking. If you want to heel strike with an outstretched leg and wear a heavy cushioned shoe with inefficient shock absorption coupled with a rigid device to transmit forces to your proximal joints, then do so. I choose not to and have helped countless runners and patients in the same manner.

Kevin A. Kirby DPM's picture

I wish I knew how to understand your form of logic, Dr. Campitelli. You first write one thing and then a few days later write something else that totally contradicts what you said in the first place. This is not science. Rather, it appears to be obfuscation with the purpose of pushing your barefoot-minimalist shoe agenda.

Let’s look, again, at what you have said over the last few days about foot orthoses.

First, you said that “literature does not support the use of foot orthotics”.

Then you said, once you were confronted with the scientific evidence that the literature does support the use of foot orthoses, that “orthotics may be helpful as a short-term solution, preventing injuries in some athletes”.

And now you say “the literature is definitely not conclusive in regards to treating foot disorders with orthotics”.

Since you can’t seem to keep your story straight, Dr. Campitelli, then let me give you, and the readers of this blog, the straight story about foot orthoses.

Does the scientific literature support the use of foot orthoses? Yes, very definitely.

Foot orthoses been shown in numerous scientific research studies to have the following effects.

Foot orthoses have been conclusively shown to be able to change the kinematics of gait by:

-Decreasing the maximum rearfoot eversion angle
-Decreasing the maximum rearfoot eversion velocity
-Decreasing the maximum internal tibial rotation
-Decreasing internal rotation/adduction of the knee

Foot orthoses have been conclusively shown to be able to change the kinetics of gait by:

-Decreasing the maximum internal ankle inversion moment
-Decreasing the impact force and vertical loading rate
-Alter knee joint forces and moments by up to 100%

Foot orthoses have also been shown in numerous scientific research studies to have the following positive therapeutic effects in treating numerous pathologies:

-Reduce pain and disability in RA and JRA
-Reduce pain and disability and alter moments in knee OA
-Reduces pain and disability from ankle bleeds in hemophilia A
-Reduces pain from patellofemoral pain syndrome
-Reduces pain from plantar fasciitis
-Reduce plantar pressures in neuropathic diabetic feet
-Helps heal diabetic neuropathic ulcers
-Relieve plantar pressure and pain from metatarsalgia
-Prevents stress fractures in metatarsals and femur
-Improve balance of individuals
-Decrease pain from medial tibial stress syndrome in runners

For the references to these articles, I suggest the following feature article and book chapters:

Kirby KA: Foot orthoses: therapeutic efficacy, theory and research evidence for their biomechanical effect. Foot Ankle Quarterly, 18(2):49-57, 2006.

Kirby KA: "Evolution of Foot Orthoses in Sports", in Werd MB and Knight EL (eds), Athletic Footwear and Orthoses in Sports Medicine. Springer, New York, 2010.

Kirby KA: Introduction to Recent Advances in Orthotic Therapy. In Scherer PR (ed), Recent Advances in Orthotic Therapy: Improving Clinical Outcomes with a Pathology Specific Approach, Lower Extremity Review, USA, 2011.

In conclusion, Dr. Campitelli, don’t let your unusual agenda to push barefoot and minimalist shoe running at any cost allow you to continue to make claims that you can’t support with any evidence other than the drivel that you read on one of the barefoot/minimalist running shoe websites. This type of writing simply won’t work when there are podiatrists, who do understand the scientific method, who are willing to stand up to you and your comments with their collective goal of seeing that their chosen profession is headed down a scientific path in establishing the most ethical and evidence-based treatments for their patients, and not down the path of anecdote and illogical conclusions to do whatever is necessary to support a shoe fad.

Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine

"Runners do not have pathological deformities. If they do, they would not be running."

Huh?

I thought our goal was to keep people active on their feet. So if patients come to your office and say they were runners for years, but now can't because their feet hurt, you tell them to stop running? You don't offer them a solution to their pain and get them back running despite their pathological condition?

I know I may be extrapolating but would like to hear more about this comment please.

Nick,
You have made outrageous proclamations which stirred numerous responses from respected individuals. Furthermore, you boast that your positions are evidence-based. Yet, when others provide a wealth of evidence which refute all of your claims, you fail to respond appropriately to the specific criticism. For example, why did you submit a reference for a "study" which has not even been conducted yet? How can you continue to make the claims about foot orthoses in light of the volume of evidence to the contrary submitted by Dr. Kirby? It is time for you to start communicating like a scientist, not a preacher.

I only have one question Nick. Can you please explain "shock absorption" to me?

Thanks

Keep up the good work Nick! Paradigm shifts are never pretty!

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