Re: RC: Re: Sport Saddles

["Truman Prevatt, PhD" <truman.prevatt@netsrq.com>]

This comment has nothing to do with the sports saddle, but it does have
something to do with the impression pad. With any sensor you need to know
what it measures and how it measures it to assess what it is telling you and
what it is not telling you. Our ears are wonderful sensors but they can't
hear frequencies above about 20 kHz, but a dog sure can. Or eyes are
wonderful sensors but they can only see an extremely small portion of the
frequency spectrum.

The impression pad takes a long term average. A short impulse of say a 3
lb/in^2 following by zero pressure for four time as long would average to
something like 0.6 lb/in^2.  The later is perfectly acceptable the former is
not related to damage to tissue. In fact depending on how rapidly the
material deforms will determine if it will see the 3 lb/in^2 peak at all.

Computerized pressure measurement systems work by taking a pressure reading
every 10 to 100 msec ( one msec the 1/1000 seconds ) which means they will
detect and measure the peak 3 lb/in^2 where the impression pads will average
it out and give you an average measurement. In essence you can look at the
impression pad not being sensitive to - and not detecting - rapidly changing
pressure, the peak of which may be in the range that it is causing damage to
tissue This is similar to the fact  your eye cannot "see" in the ultraviolet
band although this frequency of radiation is causing damage to your whole
body.

With the impression pad, a good reading is an indication that there are no
static pressure points. It is not an indication that there is an absence of
pressure points that change dynamically when the horse is in motion which
can cause damage.

Cheers
Truman


>
> I love my SS and the impression pad showed a great fit and as far as
> sitting on the spine...with a toklat pad and foam inserts my horse
> always has a nice channel sweat free down his spine.  I must add though
> I am a featherweight  weighing 120lbs during ride season and that can
> have some bearing on soreness.
>
> Linda
>