Tuesday, December 07, 2010

Is Forefoot Varus Posting Bad?

Forefoot varus is rare, yet some researchers always seem to manage to recruit enough subject for their research that have what they claim is forefoot varus. I suspect that they are not forefoot varus, but the much more common forefoot supinatus and they got confused. The reason that this is a problem is that they are totally different beasts. One is osseous and causes rearfoot pronation and cannot be reduced. The other is soft tissues and is the result of rearfoot pronation and can be reduced. Yet they look the same. They will both respond very different to foot orthoses … kinda think that the distinction between the two would be important in research projects don’t you? Also forefoot varus will respond very differently to rigid compared to flexible/semi-rigid foot orthotics.

To be clear, forefoot varus is a forefoot that is inverted when the subtalar joint is in its neutral position and the midtarsal joint is maximally pronated. As the forefoot is inverted, the rearfoot has to pronate to bring the medial side of the foot to the ground. To treat forefoot varies, you are supposed to use a medial forefoot post to bring the ground up to the foot, so the foot does not need to pronate the rearfoot to bring the medial side of the forefoot down to the ground. Right?

Consider the very rigid plastic orthotic with a forefoot varus post, when the foot is placed on top of it the forefoot varus post will invert the rearfoot (or stop it pronating/everting) through its effects on the rearfoot via the rigid plate of the orthotic.

Consider the less than totally rigid foot orthotic with a forefoot varus post. How will that affect the rearfoot pronation? The only way it can affect the rearfoot pronation is by dorsiflexing the first ray to end range of motion, then invert the midfoot joints to end range of motion, then it has a shot at affecting the subtalar joint. As the orthotic shell is not totally rigid, the forefoot varus post has to affect the rearfoot “through the foot”. Whereas if the shell was rigid, the forefoot varus posts work directly on the rearfoot by tilting the orthotic shell. It cannot do this with a less than rigid orthotic when the person is standing on it.

Is the use of forefoot varus posts potentially injurious?



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Friday, December 03, 2010

Vibram FiveFingers

Vibram Five Fingers as an alternative footwear to ‘barefoot’ have been getting a lot of attention, especially from the barefoot/minimalist running community. The anecdotal evidence is accumulating that barefoot running is increasing the injury rate in runners. I have seen predictions and posts that say something like because of ‘barefoot running’ that podiatrists must be ‘shaking in their boots’ at the thought of barefoot running due to all the business they will lose. Well, where are the people that made those claims now? The opposite has happened. Barefoot running is turning into an economic stimulus package for anyone who treats and rehabilitates running injuries. If you do not believe me, just ask them. Here is a typical comment:

"I do not see many runners in my clinic, but lately over half the ones I have seen are barefoot or minimalist runners. Given that my impression is that barefoot runers make up less than 0.01% of runners, and if 50% of the runners I see with an injury are barefoot, then should not alarm bells be going off?" source

and these types of comments:
“We’ve seen a fair amount of injuries from barefoot running already, or from just running in the Vibrams,” says Nathan Koch, PT, Director of Rehabilitation at Endurance Rehab in Phoenix, AZ. Vibrams are the barely-there “foot gloves” that have become popular among barefoot running devotees.Steve Pribut, a Washington, DC podiatrist and one of America’s most respected running injury specialists, says he has experienced a recent influx of barefoot runners at his office as well. And, asked by email whether he could confirm a barefoot running injury trend in his clinical experience, Lewis Maharam, a.k.a “Running Doc,” replied with two words: “Oh, yeah!” source

There is no doubt that some are getting less injuries after taking up barefoot running and there is no doubt that there are some that are getting more injuries.

There is even a rumour going around about a class action law suit against Vibram Five Fingers because of all the injuries that are occurring, but it may be just a rumour as I have seen nothing concrete on this. Certainly some running speciality shops have been asking customers to sign disclaimers to waive legal responsibility when the buy the Vibram Five Fingers.

There was even an insight into the sort of people who buy Vibram Five Fingers - they are being reported as being annoying people by the San Francisco Weekly!

See:
Why are barefoot runners getting so many injuries?
The Barefoot Running Injury Epidemic
Vibram FiveFingers Cause Metatarsal Stress Fractures?

While barefoot running or the Vibram Five fingers is certainly turning out to be not all they are touted as being, there is nothing wrong with barefoot running drills as part of balanced running program. Just don’t believe all the hype and propaganda that is being sold.

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Thursday, December 02, 2010

The Foot Posture Index

Measurements taken of the foot as part of a biomechanical assessment have been shown to be notoriously unreliable and not that repeatable. When the initial studies started to come out showing that, I wanted to disagree with them as “I” was reliable. That was until I became a participant in these studies and realised just how unreliable I was.

When it comes to determining the posture or alignment of the foot (for whatever reason you might want to do that!) what do you measure. The Calcaneal angle? The arch height? The transverse plane position of the midfoot? Whichever one you choose, you may end up with a ‘normal’ or ‘abnormal conclusion.

For the above to problems, Tony Redmond developed the Foot Posture Index. The index is based on observations and is based on a number of observations. The FPI has been shown to be reliable.



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Tuesday, August 31, 2010

Foot Orthotics for Golf

What do you do with a golfer and the need for foot orthotics? Golf involves a lot of walking, so they need a reasonably firm or rigid pair of foot orthotics to control the foot during that activity (assuming that foot orthotics are indicated). The crucial part of the golf game is the swing. The swing stance involves a reasonable amount of inversion and eversion of teh foot to be done efficiently. How much does a rigid orthotic with a rearfoot post interfere with that motion and affect that efficient golf swing? Foot orthotics for golf are going to have to be a compromise. It is surprising how often this issue comes up on some golfing forums for discussion.

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Thursday, August 26, 2010

The Cluffy Wedge

The Cluffy Wedge has been getting a bit of attention lately. It was original trademarked by Dr James Clough as a mean to dorsiflex the hallux to help functional hallux limitus. It was first written about in JAPMA. The concept is based on preloading the hallux to get it to load earlier in the stance phase. The biggest effect of this is to bring the windlass mechanism on sooner as it hold the hallux in a slightly dorsiflexed position. While the Cluffy Wedge can be purchased as an orthotic add-on or shoe insert, many people just fabricate their own. The Cluffy Wedge is being marketed through a number of different channels. Podiatry TV has a number of videos on the Cluffy Wedge.

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Tuesday, August 24, 2010

Foot Orthotics and Cycling

Cycling represents interesting challenges for podiatric management of problems. First the cycling bike needs to be set up properly to ensure efficient biomechanics and power generation for cycling fast. Any mechanical problem that needs foot orthotics are going to be difficult as there is not a lot of room in the shoe for cycling foot orthotics. Also there is no “swing phase” in the cycling “gait” as there is when walking and running. This can result in a type of plantar forefoot neuropathy due to the constant weight bearing (this is also seen in gyms on equipment like the cross trainers in which there is a constant stance phase). A lot of these issues is discussed amongst cyclists on cycling forums and Podiatry Arena has had a few discussions on cycling.

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Saturday, August 14, 2010

Chilblains

Chilblains or pernio are interesting when it comes to the textbooks. You hardly see chilblains mentioned. They are really common in the colder climates. I can only assume that the editors of a lot of the text books do not live in climates where chilblains are common?

The biggest misconception I see about chilblains is that they are caused by the cold. They are not really caused by cold, but are caused by the too rapid warming of the foot after they get cold and circulation has not responded adequately to that warming. They are also not caused by poor circulation, they are caused by how the cold responds to the changes in temperature, so the volume of the circulation is not an issue.

Why are chilblains more common in females? - it is either a footwear thing and that causes pressure on the toes that causes changes to the circulatory response; or it’s a hormone thing as a lot of the female hormones do affect the circulatory responses.

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Sunday, August 08, 2010

Foot orthoses or gait retraining for patellofemoral pain?

Its long been held that excessive foot pronation causes the tibia to rotate excessively internally causing a misalignment of the patella and results in patellofemoral pain syndrome or anterior knee pain in runners. Therefore, based on this you use foot orthotics to correct the foot pronation to treat the problem. Two reasonably well conducted RCT’s shows that foot orthotics are successful at that.

However:
1. Almost the cross sectional and prospective evidence shows that foot pronation is not associated with patellofemoral pain (despite the fact that foot orthotics been shown to help).
2. Even though the foot and tibia are coupled, the research as to which is the driving force, shows that it is tibial internal and external rotation that drive foot pronation and supination. It is not foot motion that drives leg motion, it is the other way around (see this discussion). This is so counter-intuitive to what podiatrists, in general, have believed.
3. More and more physiotherapists are using proximal control exercises and gait retraining to treat patellofemoral pain without the use of foot orthotics, and the evidence shows that this is just as effective as foot orthotics in treating this problem.

What is going on? Is it proximal or distal that the problem is coming from? Should we really be using foot orthotics is the problem is proximal? Should physiotherapists be using proximal control exercises if the problem is distal?

I have been in a couple of conference debates with physiotherapists at both a physiotherapy and a podiatry conference. I have learnt a lot through that and I genuinely do believe that the solution to patellofemoral pain syndrome is proximal control exercises. However, I also believe that this proximal control will not work if the ankle inversion moment (or supination resistance) is above a certain threshold (which will probably vary from individual to individual). For example, if the ankle inversion moment is low (i.e. supination resistance is low), then the proximal control exercise should work easy to help and they may not even need foot orthotics. However, if the ankle inversion moment is high (i.e. supination resistance is high), then it does not matter what you do proximally, it’s not going to work as the foot won’t move. So, therefore the role of foot orthotic in patellofemoral pain could be to reduce the ankle inversion moment to below a certain threshold, so the proximal control can work. This theory makes sense to me and is consistent with the most recent evidence.

For more see:
Foot Orthoses for Knee Pain
Foot orthoses and patellofemoral pain syndrome
Foot pronation and knee pain
Does the tibia drive the foot or does the foot drive the tibia?

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Saturday, July 10, 2010

Peroneal Tendonitis

Peroneal tendonitis is an uncommon overuse injury that occurs to the peroneal tendons and sheath, usually just above or below the lateral malleolus. I never used to like seeing patients with peroneal tendonitis. They never seem to get better when I treated them and it always puzzled me. It always great when the research you do has an impact on your clinical practice. This is exactly what happened with peroneal tendonitis. We looked at the force needed to supinated the foot in those with it and it really surprised me how low it was. It was so low, that it easily explained why the tendonitis was there .... it was because the peroneal muscles had to work so hard to stop the foot supinating. That now makes peroneal tendonitis easy to treat with lateral wedging. Changes in running form also alter the load in the peroneal tendons.

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Saturday, June 05, 2010

What’s up with the Weil Osteotomy?

What’s up with the Weil Osteotomy? Not doing any surgery I was not up to speed with opinions about this. First there was this blog post condeming it. Then there was a point/counterpoint debate in Podiatry Today, followed by a poll on the Weil Osteotomy on Podiatry Arena.

Tuesday, April 06, 2010

Severs Disease

A tight calf muscle has often been mentioned as a factor in Sever's Disease or Calcaneal apophysitis in kids. When you examine a lot of these, the calf muscles feel tight. But how do we know that this has anything to do with the cause of this problem? ...we don't. There are 3 explanations:
1. The calf muscles are tight and they were a cause of the problem
2. The calf muscles are tight, but the tightness came on after the Sever's developed due to, perhaps, some gait alteration
3. The calf muscles are not tight, but appear tight on examination due to a splinting like action due to the pain.

Which of these is the answer? ...I have no idea.

For the latest see Podiatry Arena on Severs Disease; or this video on calcaneal apophysitis on PodChatLive.

If you have Severs disease then it all comes down to managing the loads via modficiation of the activity and perhaps using a cushioned heel pad.

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Sunday, March 28, 2010

Medial Tibial Stress Syndrome

Medial tibial stress syndrome is something that has always bugged me because I do not know exactly what it is. There are many competing theories that are underpinned by some good research as to what the exact pathophysiology of the condition is. Some of the theories are not consistent with each other. One recent idea that has caught my attention is that medial tibial stress syndrome is bone stress reaction due to increased bending moments in the tibia. Some of the rationale behind that does make sense to me. There is some discussion on this at Podiatry Arena (see: Medial Tibial Stress Syndrome)

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Thursday, March 25, 2010

Terminology of hallux rigidus and limitus

I do get a little frustrated at the confusion surrounding the terminology of these conditions. To me hallux rigidus means just that: i.e. the hallux is rigid (it does not move). Some people use ‘rigidus’ for a reduced range of motion and some use it as another name for osteoarthritis (which obviously most cases of structural hallux limitus have). Also the term hallux limitus is a tad confusing - is it a structural hallux limitus (which some like to call hallux rigidus) or is it a functional hallux limitus (which some do not think even exists). So this is what I call things:

Hallux rigidus = no motion at the joint
Structural hallux limitus = structurally reduced range of motion
Functional hallux limitus = functionally reduced range of motion

BUT, then again, they can all be reconceptualised as a change in dorsiflexion stiffness at the first MPJ, so let’s toss all the names out.

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Thursday, March 18, 2010

The real need in plantar fasciitis treatment

Everyone has their favourite treatment for plantar fasciitis and each technique has its champions claiming that it is the best. How can they all be right?

At the end of the day, true plantar fasciitis is due to excessive load in the plantar fascia, so the only way to treat plantar fasciitis successfully in the long term is to reduce that load. I can think of only 2 (maybe 3) ways in which the load can be reduced in the plantar fascia. One is low dye strapping and the other is with certain foot orthotic design parameters. The potential third way is calf muscle stretching as there are some fibres from the Achilles tendon that pass through to the plantar fascia.

All the other modalities such as cortisone injections, shockwave therapy, cryosurgery, active release techniques, magic wands, crystals, deep tissue therapy, TOPAZ, trigger point therapy, nerve blocks etc , etc only help with the healing of the damaged tissue. Not of these can actually lower the load in the damaged tissue.

The long term management of plantar fasciitis is dependent on the load in the tissue being reduced, not depending on some pivotal magical cure that does not reduce the load.

See these for the latest on plantar fasciitis and low dye strapping, as well as this approach.

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Saturday, March 13, 2010

The paradox of sinus tarsi syndrome

Sinus tarsi syndrome is somewhat paradoxical in that it can be caused by inversion, as in an ankle sprain damaging the structures in the sinus tarsi by stretching them; and it can also be caused by eversion, as in a pronated foot with high forces pushing the subtalar joint to end range of motion and causing compression forces at the bony end range of motion. The structures in the sinus tarsi and their role is very complex and poorly understood. A better understanding will better help direct therapeutic approaches. However, in both the pain is on the outside of the ankle joint. Generally, the inversion type responds well to physical therapy intervention and the eversion type responds well to foot orthotics.

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Thursday, February 04, 2010

More on barefoot running

I have previously blogged about barefoot running and how bad research on barefoot running gets reported. Now we have a publication in Nature that has been widely reported in the media and touted by the barefoot running community. The interpretation and use of this research has been so bad, that the authors took the unusual step of posting this disclaimer on their website:

There are many discrepancies in the way the press has reported our paper “Foot strike patterns and collision forces in habitually barefoot versus shod runners” (Lieberman et al., Nature, 463: 531-565) .....Please note that we present no data on how people should run, whether shoes cause some injuries, or whether barefoot running causes other kinds of injuries.

Now we have an anti-barefoot running website that has been set up to critically analyse the claims made. It appears to have touched a raw nerve in the barefoot running community. They do not like it when they get criticised, but think it is acceptable for them to criticise others ... don't figure! Even a Fench running website is highlighting the barefoot running debate.

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Saturday, January 16, 2010

RSS Feed

For those of you who know what RSS is and have a RSS reader, the RSS feed of this blog is at:
http://podiatric.blogspot.com/atom.xml

Please subscribe to get instant update of posts.

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Thursday, January 07, 2010

Barefoot running and BAD research

I just do not get how the media react and create headlines from research (well actually, I do get it ... they want to attract readers and sell papers), but they just have to be more responsible. A lot of bloggers fall for the same trap.

A few days ago there was some research published that looked at joint torques when running barefoot vs running in running shoes. Some of the headlines that accomapanied news and blog reports about this research were:
Running Shoes are Still Bad
Running Shoes may cause damage to knees hips and ankle
Running may be good for you, but running shoes aren't

What I do not get is that there was absolutely nothing in the research that actually showed this! Let alone the flaws in the study do not allow any conclusion to be drawn, let alone the above ones. Also, it turns out the lead author has a vested financial interest in a barefoot running product that was NOT disclosed!

The barefoot running fanatics and irrationalists have jumped on this research as supporting the barefoot running movement. The fact that they blindly accept this research without any form of critical analysis of the flaws, just confirms how fanatical and irrational they are!

Why can't the media and bloggers be more critical in what they report? At least Podiatry Arena could see through the problems: The Effect of Running Shoes on Lower Extremity Joint Torques

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