Comparing Silicone Dynamic Orthotics with Traditional Orthotics by Computer
Traditional orthotic technology has been around for over 60 years and has been based on theories about the foot and its mechanical function (aka "biomechanics") for the last 100 years or so. This technology tries to control foot function from the rear foot.
This basically winds up being a “fixed” position of the arch when it needs support NOT ONLY under the arch, but under the forefoot too!!
The Silicone Dynamic Orthotic (SDO) is an encased fluid orthotic and is based on the principles of "fluid mechanics" utilizing hydrodynamic pressure to lift and support the arch and forefoot and holds it up under the weight and pronatory forces of each and every step by equilibrium (the foot cannot compress beyond the fluid's limit to expand.
Computerized systems allow us to compare the efficacy of different orthotics. The system records the distribution of pressure underneath the foot as a person walks across our pressure-sensitive mat. The results we will review below are from real people. It is the intention to compare the efficacy of a barefoot, with the patient’s own traditional orthotics, and the SDO.
How to read and understand the "Tekscan" pressure measurement system
The color scale on the left of each picture represents the amount of pressure seen on the bottom of the foot (aka "ground reactive force"-GRF). Low GRF is in blue, moving toward red, which indicates a higher GRF. This pressure is an indication of balance and alignment in the foot . The degree of pronation and misalignment has a direct relationship of balance, alignment and efficiency throughout the musculo-skeletal system.
The picture you see is an average of pressures accumulated through the gait cycle (heel contact through toe-off). Four areas to look at:
1. Heel contact—the impact of pressure at heel strike (it must be noted that it would be unfair to compare the SDO, with any other orthotic, because of the composition of the orthotic itself. Only the SDO can demonstrate heel contact in its natural state.)
2. The filling of the arch as the foot is moving forward. The color indicates the measure of “balance” of the midtarsal joint complex AND FOREFOOT.
3. The pressure under the 1st metatarsal head as it is loading to the ground first.
4. The distribution of the pressure under the ball of the foot from loading up AND loading down.
The easiest area to see the “balance” of the foot with an orthotic is the pressure under the ball of the foot. The better the "pronation" minimization (reducing pronation movement), the more spread out and evenness of pressure against the ground.
When the ball of the foot pronates the more it allows the middle and back of the foot to pronate also. As the rearfoot further pronates the front of the foot also has more room to pronate further (this is "unlocking"), leading to instability. This motion goes back and forth as far and as fast as it can. This then is "maximum" pronation AKA "overpronation" with each footstep and creates "wear and tear" to our lower extremity posture over a lifetime.
In the following sequences of comparisons between the distribution of forces
and pressures in the foot with traditional orthotics and with the SDO,
understand that the individuals tested have been using their orthotics
with success (of varying degrees) in relation to their symptoms. Therefore,
we are not trying to say that traditional orthotics are bad, we are only
showing the difference in the efficiency of the way the two orthotics