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!

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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