Ask Randall: Generic Insoles

April 16, 2008 11:45 AM

Hi Randall, I was wondering if you can tell what elements are needed for a generic insole that would bring comfort to a shoe wearer. What material would you use? By the way your blog is amazingly full of facts and I am enjoying reading each post. SA

Dear SA,

In the shoe industry, the term generic insoles refers to what's also called a sock liner, contoured insole, or generic orthotic.

• Sock liners are generally a flat cushion layer, sometimes removable, but usually glued into the shoe.
• Contoured insoles are formed from molded foam to fit the shoes interior and cup the the mid-foot and heel around the edges. Generally this insole has little to no anatomy.
• Generic orthotics are formed from molded foam or/and other materials. It is like a contoured insole, but has actual arch contour and more anatomy.
  

Here's what I think are the best choices in each category:

• Sock Liners: Multi-density foam layers. One layer that forms to the foot layered over one resilient layer that springs back to the original shape.
• Contoured Insoles: The same as a multi-density sock liner, but with the upper layer being a molded foam shape.
• Generic orthotics: Typically an after-market product, sometimes they are actually built into a shoe such as a Birkenstock. The most important thing is that the contour doesn't offend the user's foot contour.
  

The object to orthotic contours is to guide the foot to it's optimal use. The closer the contours are to the foots natural contours, the higher the performance of the orthotic. Peoples feet are different, therefore a mass market product will only address one type of foot over another.

The optimal high performance is a custom orthotic. Because this option isn't available to everyone, the next best thing is to try on a multitude of generic orthotics to seek a good match.

Note: I offer consulting to manufacturers and designers seeking information about foot contours, orthotic shapes and materials. In the past I've patented two systems relating to this research.