Notty Bumbo wrote:
> 
> Oh Great Chipster!
> To have gotten a reply from thee! I am so honored! But beyond that - I long ago, (and
> some say, far away) developed a modification to both the Blake and the medial skive
> proceedures that solves some of the difficulty I came up against with their mutual
> standard approaches. I have spoken of this modification many times - I call it the
> Valmassy modification, because Ron was the first clinician to be willing to try it out
> with his patients, (and because I couldn't very well call it the Quasimodo
> modification, now, could I?).
> 
> This mod was developed in response to what seemed an obvious problem with both
> approaches, to whit (always wanted to say that), when the cast is either inverted, for
> the Blake, or the medial anterior aspect of the plantar heel of the cast is shaved and
> re-shaped, as in the medial skive, the volume and width of the heel cup is
> significantly changed. In fact, it is made narrower. Any resultant orthoses, assuming
> the standard lateral expansion amount and shape is employed in either case, results in
> a heel cup that is too narrow for the patient. This is easy to see if you view the cast
> posteriorly, then invert the cast, after drawing a heel cup depth line aroung the
> circumference of the heel, say, 20 mm.
> 
> So it is clear that the standard approach to lateral expansion is insufficient for
> either of these cast correction approaches. But the problem extends to more than width
> and volume - it also involves the shape of the lateral expansion. The act of skiving or
> inverting the cast in effect "lifts" (I know, not very scientific, but it is true) the
> medial aspect of the heel. As the calcaneous is, at least the last time I looked, a
> rigid bone, then any change in elevation along one side of that bone must create an
> opposite effect on the other side of that bone, i.e., it "drops". So big deal, you say.
> What of it, you snarle. No skin off my back, you sneer. Well, maybe you didn't do all
> those things.
> 
> If the lateral side drops as the medial side is lifted, then the lateral expansion must
> respond to that basic fact. The standard shape used for lateral expansions creates
> resistance to what the orthoses is attempting to accomplish along the medial aspect. By
> using a Valmassy modification, the orthoses can usually accomplish the same amount of
> control with a lesser degree of cast correction overall. To get an idea of this shape,
> simply take a standard Root-style orthoses, viewed posteriorly, and rotate into
> inversion. Observe the lateral heel against a verticle bisector. Now, increas the heel
> cup depth along the lateral side while maintaining that shape. Wallah, as they say in
> India.
> 
> Oh, I do go on. I'd be glad to show you this at the seminar in October. Glad you'll be
> on board.
> 
> Latte, as they say in California.
> Notty Bumbo
> 
> dorsalis wrote:

Most benificient Quasi Notto

All of the utterances above are great pearls of truth.  In fact, we
encountered the same problem which you describe with patients standing
on the lateral border of the orthotic (Not an experience highly reviered
by them to be sure)when we first started using Kirby medial skives
fabricated by local labs. Truely, the modification of the lateral
expansion is key to making the inversion force consistent with patient
tolerance.  I can offer not elaboration on your most eloquent hypothesis
there.  

What I think is most remarkable about the Blake device, and what I was
referring to in the Ray Anthony formulary was the FF to RF
relationship.  The first time I saw a Blake device, what struck me most
was not the inverted position of the rearfoot or even (sorry to say now
realizing its most glorious inception) the modification of the lateral
expansion.  It was the gargantuan intrinsic forefoot post which leveled
to the gravity plane of the upper positive inverted cast.  It is that
which renders the extraordinary balance between inverted rearfoot and
forefoot and that to which I was referring in the commentary. 

I do very much look forward to seeing your modified lateral expansion. 
No one down here does it very well.

Tentorially

Chip S.


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