The side view of the laminate (runner's) model (on the left). It is from you the observer, a right foot orthotic. It is approx 3/8" thick from top to bottom. I've used a worn model so you can see the wear and the outline of the orthotic inside. (also see top view)
The edge closest to you is the inside (medial) of the right foot
You can also see the hydro-dynamic fluid distribution (after stepping on it) and equilibrium state of my "stability" at the critical moment of "midstance" (when the total bottom surface of my foot is in contact with the ground/shoe)
Starting at the heel to the extreme right of the picture, you can see the outline of where the heel has displaced the fluid forward, (it's flat, because I just stepped on it). That's the orthotic itself, embedded in the laminate materials.
In the middle of the orthotic you see a spread out lump. That's the fluid displaced to the central part of the arch (the MTJ: midtarsal joint).
If you follow the thickness down the inside (under the big toe), you can see the fluid thicker from top to bottom, than if you look across the page at the far side of the foot.
Now it's very hard to see from the picture, but if you look at the wear pattern across the ball of my foot, you can see a slight angulation as the fluid is spreading out under the forefoot as it moves up to the central mass and then the deepest depression down is where my forefoot is on the ground (midstance phase).
The fluid is displaced according to the weight bearing pressures and pronatory forces, guiding my foot into that position, the "equilibrium state of stability". This effect of physics means that the fluid is spread out as evenly as possible and the pressure within the fluid is equal throughout.
** This is the moment when my foot is MOST STABLE, with the least amount of pronation/supination throughout the entire foot.
NOW, what adds to makes this orthotic different from every other orthotic in the world is what happens after the heel lifts up for the beginning of propulsion.
If you can imagine my foot pivoting onto the forefoot as I'm moving forward, I have higher weight-bearing forces (per sq. inch) on the forefoot, coupled with the weight-. bearing and pronatory forces of the foot. The fluid is starting to be pressed BACK into the back of the orthotic for the next step. BUT, as the fluid is moving back IT'S STILL under pressure supporting the forefoot and midfoot and this is prolonging the support of "the equilibrium state of stability" under the fore and mid-foot. It's just momentary, but a foot step in a traditional orthotic doesn't work this way, because the device allows the forefoot to pronate, and become un-stable through the forefoot and midfoot. This break in pronation and instability effect is what potentially wears and tears our biomechanics of the lower extremity down as we age. Feeling the ill effects of this little bit of pronation over 40-60 years of age is normal.
The fluid technology above is truly a custom arch support that works the way an orthotic should!
If you are interested in my article published in "PODIATRY TODAY" you can access it here: http://www.podiatrytoday.com