Thursday, August 28, 2008

Leg Length differences

This can sometime be a hot topic. In orthopaedic circles, what is considered a significant difference between the two legs can be quite large and in chiropractic circles what is considered significant can be quite small. Both sides of the argument can be quite passionate about this.

Reminds me of Payne's Law: "The amount of passion involved in defending a theory and the amount of emotional attachment to a theory is usually inversely proportional to the amount of evidence for that theory"

There is no doubt that having a leg length difference does affect the quality of life and there are many way to measure a leg length difference clinically. There are also just as many arguments about how the body compensates for a leg length difference.

Podiatry Arena has built up a valuable resource of threads that have been tagged for leg length difference, that explores all these issues.

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Monday, August 11, 2008

Functional hallux limitus

I am privileged with the honour of being invited to speak at many conferences. Most recently was at the Podiatric Surgeons conference. When I agreed to speak, I did not think to much about about the topic until I was back from another conference, then I had a OMG why did I agree to talk about that moment ? What the hell am I going to say?

One reason I enjoy speaking at conferences is that it forces me to organise my thoughts and "put them on the line", so I thought I would try and take our traditional understanding of first MPJ dysfunction (ie hallux rigidus; structural and functional hallux limitus) and the windlass dysfunctions (ie no windlass; delayed windlass; high force to establish; disruption during loading) and reconceptualise them in the framework of the mechanical engineering terms of 'stiffness'.

While going through the dot points, I got struck by something: All functional hallux limitus really is, is a temporary increase in the dorsiflexion stiffness of the first MPJ ! It got the thought processes going. (I have written about it here: Reconceptualising Functional Hallux Limitus)

Traditionally we have considered FnHL as being present or absent, when in reality it probably exists on a continuum. If we conceptualise it as a temporary increase in first MPJ stiffness, it then opens the possibility of grading functional hallux limitus (ie a low temporary increase in first MPJ stiffness to a high temporary increase in first MPJ stiffness). Maybe we can measure this !

Should we reconceptualise FnHL as a temporary increase in first MPJ stiffness? What say you?

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