2. 3. OPCT Concept CONSTRAINTES OF PLANTAR ORTHOTICS Nouveau logo
Permanent compression will be practised on the material...
Friction between the foot and the top cover…
The forefoot flexion will be more important ...
Shear between top cover and the foot ...
Sweating on the top cover ...
Nouveau logo 2

3. Materials in podology Metal Natural materials (cork, leather…)
Synthetics materials
Advantages of using synthetics materials:
Innovating
Anti bacterial
Washable
More performance

4. Materials in podology The 3 layers of a plantar orthotic top cover
base
elements

5. Synthetics materials E.V.A (Ethyle Vinyle Acétate) P.E (Poly-Ethyléne)
Foam resisting to abrasion, becoming smaller and stiffer if too much heated
P.E (Poly-Ethyléne)
More fragile to abrasion but more resisting to heat
Hybride (EVA/PE)
P.U.R (Polyurethane)
Liquid resins of expanded foams
Polyamide (Nylon 6/6)
Caoutchouc (naturel or synthetics)
P.V.C (Poly vinyle)
Resins
Polyester (on a base of cotton or nylon) very hard
Other types based on carbon fiber or kevlar (+ or – easy to thermomold)

6. Technical notions Stiffness = shore (A) Density Remanence Absorption
Cushioning
Viscoelasticity

7. Technical notions Shore (A)
Stiffness of a material. Plantar pads have a stiff shore A between 10 and Polyester resins are between 96 & 98.
Hardness = resistance of a material to permanent penetration by another calibrated material, under a constant force
According to the hardness of the material, the rod will sink more or less to allow the system spring / material to reach static equilibrium: The measurement of the Shore (hardness) is possible on materials that have a homogeneous surface.
Ex : The average Shore hardness of the skin is 43

8. Technical notions Density (kg/M3)
Weight for one cubic meter of materials.
High density  resists under the weight of patient.
High density  durability of the material
+++ Density  +++ Stiff
Material Density = Mass Volume V material Mass Volume V Water
If this density is greater than 1, the material flows. If this density is less than 1, the material floats.
Ex : Water = 1 Aluminium = 2.7 Platine 21.45
Steel = Gold = 19.3 PE= 0.140

9. Technical notions Remanence
The remanence of a material is its ability to regain its original dimensions after prolonged deformation.
Measurement process :
Loading the material (to deform it) for a given time (72 hours) at a given temperature, and then removing the charge.
Measuring the difference between the initial thickness and the thickness after loading
 Dynamism & durability

10. Technical notions Absorption Cushioning
Capacity to stop the propagation of a big quantity of vibration.
+++ Absorption = --- sensibilisation of sensorial captors & proprioceptive
Cushioning
Capacity to absorb a big quantity of cinetic energy = needs thickness
Warning :
Too much cushioning = muscular effort : injury
Foot too far away from the ground = unstability

11. Technical notions Viscoelasticity
Capacity to change a vertical pressure into a lateral pressure and come back to the original shape.
Silicone, neoprene, « Sorbothane » are viscoelastic materials.
An important thickness of viscoelastic material can inhibit proprioceptive captors (ex : + 3mm of neoprene

12. Which material ?
Choose the right materials in function of some requirement :
The walking perimeter ...
The activity of the patient ...
His size ...
Fitting volume ...
Pathology ...

13. PODIATECH classification
Specialised materials at the forefront of your profession.
Tried and tested materials that you can choose with complete confidence.
Generic materials accessible quality.

14. PODIATECH classification
Top Layers
Synthetic
Foam
Bases
Resin
Technical materials
Shock absorption
Propulsion
Active / Passive protection

15. PODIATECH classification
Low activity
High activity

16. PODIATECH classification
Low activity
High activity