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

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

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

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)

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

Technical notions Shore (A) Stiffness of a material. Plantar pads have a stiff shore A between 10 and 15. 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

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 = 7.85 Gold = 19.3 PE= 0.140

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

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

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

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

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.

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

PODIATECH classification Low activity High activity

PODIATECH classification Low activity High activity