Prescribing
EVA or Poron? Choosing a top cover for a custom orthotic
A top cover is the layer between the foot and the orthotic shell. On an ORTX device the shell does the mechanical work and the cover handles comfort, friction and fit in the shoe. Covers are optional: many patients do well on an uncovered PA11 shell. When one is wanted, the two choices are EVA and Poron.
EVA
Ethylene-vinyl acetate is a closed-cell foam. It is light, firm, durable and easy to keep clean. It adds a little cushioning without changing how the shell feels underfoot.
- Good for: everyday and sports wear, patients who like a firmer feel, devices that see a lot of moisture or hard use.
- Trade-off: less shock absorption than Poron, and like any foam it compresses gradually.
Poron
Poron is a microcellular urethane designed to absorb impact and spring back to its original thickness. It feels softer than EVA and holds its cushioning for longer.
- Good for: plantar heel pain, fat-pad atrophy, older or diabetic feet where pressure matters, long hours standing on hard floors.
- Trade-off: slightly heavier and warmer than EVA, and it costs more to make.
Sulcus or full length
A sulcus-length cover stops just behind the toes, at the sulcus. It suits shoes where the orthotic sits under the original insole, or where toe room is tight. A full-length cover runs to the end of the shoe and replaces the factory insole, so it suits shoes with removable liners and gives one continuous surface under the forefoot. On ORTX devices both lengths are made the same way.
How to specify it
Choose the material and length in the Top cover section of the ORTX Pro script. If you are unsure, add a note and the lab will recommend one based on the complaint and the footwear listed.
Health professionals
Order fully custom orthotics, made in Brisbane, through ORTX Pro.
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