DearTrevor,
I'm sorry I can't email you on the side. But, although I
am still an undergrad pod.... one thing I do know a bit about is the feed
back from Aussie skiers.....having been in this business for 18 yrs. I get
lots of skiers complaining of medial knee stress and fatigue.... its usually
people with an RCSP that is everted/pronated and I have always thought this
due to the extra internal rotation and pronation that these people have to
go through in order to set an inside edge, it may not be this actually
causing the symptoms but it's present. I have always thought that the extra
medial shift of the knee which usually accompanies these movements renders
the whole structure less able to cope with stresses involved. When you put a
large solid "arch support" under these feet (no 1st ray PF needed) this
decreases the amount of STJ pronation and internal femoral rotation
required in order to set an edge and respond to the forces of angular
momentum that are generated in a turn, this in turn allows the whole leg to
remain more in a sagittal plane leaving it more able to cope with forces
than if it had been deviated in the coronal plane more at the knee. I'm sure
some one out there can set me straight if this seems illogical.....Please go
right ahead........
Regards Phill Carter
-----Original Message-----
From: [log in to unmask] <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Wednesday, 3 March 1999 6:51
Subject: Re: MTJ axis and orthoses,forefoot abduction and lever length re
skiing
>In a message dated 01/03/99 14:54:18 GMT, you write:
>
><< I just read Eric's excellent posting and would like to add a few brief
> comments. I believe the greatest problem for skiers who have a mechanical
> condition that allows excessive forefoot abduction is the fact that they
> normally compensate by internal leg rotation (via stj pronation). Even
>though
> the leg is internally rotated these individuals do not seem to be able to
get
>a
> good inside edge (weight the medial edge of the ski).
>
> These skiers are usually individuals who fatigue more readily. An
orthosis
>that
> reduces the amount of internal leg rotation will allow the skier to get a
>better
> inside edge, allows the ski's to track in a more parallel fashion, and
will
> promote more efficient function of the leg muscles thereby reducing
fatigue.
>
> In down hill skiing many of the top level skiers have what is described as
a
> rigid, cavus foot type. These individuals are able to rapidly transfer
>weight
> on and off the inside edge of the ski, hence are able to control their
turns
> better than individuals with other foot types. They also typically have
very
> large, powerful calf muscles.>>
>
>Is the cavoid foot an observation or is there a reference for this? Is it
>possible that the foot and leg you describe may be developmental i.e. they
>were good kiers from an early age and thus the muscle strength and foot
type
>follwed this path ?
>
> >>In theory, when an individual with excessive transverse plane motion of
the
> forefoot attempts to apply pressure to the anterior, medial edge of the
ski,
>the
> forefoot abduct which produces stj pronation and internal leg rotation.
So
> these skiers have great difficulty applying pressure to the *tips* of
their
> skies even though the rearfoot is pronated. As a result they are less
able
>to
> carve a turn in the snow and therefore have less control.
>
> For those of you who prescribe orthoses for ski boots, you may want to add
a
> forefoot extension to support the patient's forefoot inversion or
eversion.
> This will increase the skier's ability to edge their ski. >>
>
>My limited experience of this certainly confirms that skiers report an
>increased ability to cut with orthoses. However, they also report increased
>stress to the knees as a result.
>
>Trevor Prior
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