The Journey of Custom Orthotics

Most people have heard of custom orthotics before. They are insoles specifically made for an individual’s feet, designed to treat a specific condition. That’s their beauty. They can be fine tuned to treat that person’s foot/lower limb problem like no other device. If you have a high arch with a sore spot on the ball of your foot, you can get custom orthotics that are perfectly fit to your high arch, and specifically designed to relieve the pain from that specific sore spot. Have I said they are highly specific?

In today’s blog I wanted to share the behind the scenes journey of custom foot orthotics to describe to you how exactly they are made to treat YOUR feet. Fair warning, this post might be a bit long, but custom orthotics are something I am passionate about.

So lets get started:
Custom orthotics go through quite the journey before they arrive as their final product. Let’s go through the process. First a biomechanical assessment and gait analysis is performed by the Chiropodist to determine what the patient’s foot problem is, and how to treat it. If custom orthotics are appropriate, a cast would be taken of the patient’s feet.

I have to talk a little more about the cast. The cast is absolutely critical in creating well-fitting orthotics. There are several casting methods out there. You must get a 3D cast in order for the orthotic to contour the shape of the foot properly. So we can “X” the pressure plates. Those only show 2D data; high and low pressure areas – which if used with a 3D cast can be useful, but not on their own. There are a few ways to get a 3D cast of the foot: plaster slipper cast, 3D laser impression, wax mold, and foam box. I prefer the plaster slipper cast and employ that method at The Foot Fixers. The plaster slipper cast is a messy, time consuming process, but it creates an incredibly accurate cast (it even captures skin lines). It also allows me, the Chiropodist to hold the foot in the proper position, called “subtalar neutral”. This position is where the foot is aligned with the ankle and leg. It is the position you want the orthotic to hold you close to. Weightbearing casting methods like a standing in a foam box would instead capture a cast of your foot in a “compensated position” , ie. not subtalar neutral.

OK, so once the cast is taken it is sent to a lab for manufacturing. I did not know much about this process until I studied and became a pedorthist. As a pedorthist I made orthotics from scratch in a lab countless times, so I am talking from experience.

In the lab, plaster of paris is poured into the slipper cast. When it hardens, the slipper cast is broken off and disposed. You are left with an exact mold of the patient’s feet. Once these molds are smoothed out and angled to specifications, they are used to press materials to. Materials used in custom orthotics range from very hard to very soft, depending on the specific needs of the patient. Harder materials are typically thinner and better at controlling the foot. Softer materials take up more room in the shoe but are more cushioned. Some common shell materials include polypropylene, carbon fibre, EVA and cork. The shell material is heated up and “pressed” over the foot molds using a vacuum press. Once the materials cool, they hold the shape of the foot. They are starting to resemble orthotics. The molded material is then ground down to the specific depth specified on the prescription. Next, any additions are added. There are several additions the Chiropodist may prescribe, such as metatarsal pads, forefoot extensions or heel cushions. Once the additions are complete, they are covered with a top cover. Top cover materials are choseen based on what the orthotic will be used for. Some common materials include leather, vinyl, EVA of different densities or neoprene. Once the top and bottom covers are glued on, the orthotics are complete. One last quality control check, and they are shipped back to the Prescribing Chiropodist’s clinic for dispensing to the patient.

At the dispensing appointment, the orthotics are checked against the feet to ensure a good fit, and trimmed to fit the footwear. And that’s it! The journey of custom orthotics.

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