Notty asked for some more clinical case discussions so I will pose one after
some theoretical discussion.

In a message dated 98-04-16 19:04:53 EDT, Notty wrote in response to Craig
Paine.


> 
>  Well, CP, there you go again, throwing the bathwater into the wind. Just to
>  make the point,
>  the existence of one or several papers does not refute any theory. If we
are to
>  be arguing scientific method here, then let's all step back a bit and
>  re-examine exactly what it takes to actually refute a theory, especially in
an
>  area as fraught with complications as the biomechanics of the foot and
gait.

some cut

>  
>  I think where I, and apparently some others on this list, have concern, is
with
>  the rather shrill nature of the slam on Rootian biomechanics, without any
>  greater data being presented which supports or defines any other effective
>  theory. We have tools which have produced somewhat reasonable outcomes for
a
>  high percentage of patients over many years. The sign of true scientific
>  inquiry is the ability to use and respect what has worked while seeking to
>  further the understanding and the theory. I don't think we need to get
slammed
>  against the wall for our insistance on using tools that, despite legitimate
>  concerns, still get the job done most of the time.

Notty, in your mind, what would it take to refute Root et al's theory?  We
have not proven that orthoses do  work (I believe that they do, especially on
my feet.)  So let's say that orthoses work at least some of the time.  This
does not mean that classical biomechanical theory explains why they work.  The
reason that supporters of classical biomechanical theory are getting "slammed"
is that the theory is not fitting the observations except for the observation
that orthoses work some of the time.  The analogy of thinking that the Earth
is flat is a good one.  People were able to navigate the sees fairly well even
though they thought the Earth was flat.  Too navigate the seas better, you
have to abandon the theory that the Earth is flat.

We need to understand why they work some of the time and how to make them work
often.  I believe this can be done by modeling tissue stress.

Case presentation:

Posterior tibial tendonitis.  Medially deviated STJ axis.  When patient fires
their peroneus brevis in stance they are unable to lift their lateral forefoot
off of the ground, because there is no range of motion available.  A neutral
position cast is taken (we could take it some other position, but for sake of
argument take it in neutral).  The cast has a perpendicular forefoot to
rearfoot relationship.  On the affected side, in stance, the height of the
skin under the navicular is .75".

1. What additional information would you want to write your prescription for
this foot.  2. And, most importantly, how would this information change what
you would do to the finished shape of the orthosis.
3.  How would you prescribe the orthosis for this patient.

My 1st attempt:
Neutral position is not needed.  Balance cast vertical and add a 4mm medial
heel skive.  (Vertical so no nails are added.  This would be much more
important if there were a forefoot valgus in the cast.  The lack of range of
motion in the direction of eversion would mean that a forefoot valgus
correction would be trying to push the foot farther than it could go in the
direction of pronation.)   Ask lab to fill in arch so that finished orthosis
is .75" high.  The theory behind the arch height is that this would be
"comfortable."  A minimal medial arch fill might demand more activity of the
posterior tibial tendon.

I believe this orthosis would work for this individual because the inverted
device would reduce the pronation moment from the ground and the patient would
then use there posterior tibial tendon less.  More use = more pain.  My point
is you can make a piece of plastic that could make this patient feel better,
without using traditional theory.

So let's create a virtual bag of orhtotics for this patient, with reasoning
for changes included.  I forgot who it was who said they felt very sorry for
the patient who had a bag of orthoses.  I would feel more sorry for a patient
who had a failed surgery to attempt to treat a problem, especially if it could
have been helped by orthoses.   You can carry a failed orthosis in a bag.

Looking for the horizon,

Eric


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