Like anything else that is custom made, a custom made orthotic will be designed specifically for your foot and your medical complaints.
There are many things that can be adjusted and modified on a custom made orthotic. Let us start with the basic orthotic shell. First, there is the length of the orthotic to consider. Most labs offer three lengths (3/4, sulcus and full length) for their orthotics. The proper length for you depends on the purpose of the orthotic and, more importantly, what kind of shoe your orthotic is going to be worn in. Once the length has been decided then the width needs to be considered. Once more, the type of shoe that the orthotic is going to be worn in will dictate this. Finally, for the basic shell a choice of top-cover needs to be made. The purpose of the orthotic, again, will dictate this. For sports, you may get a 3mm top-cover with maximum shock absorption with infused fungicide; For dress shoes, you may opt for a star-suede top-cover that is only 2mm thick, infused with a fungicide and backed by foam for shock absorption
The next consideration for a custom made orthotic is does it need to be posted? Posting is done to the forefoot and/or rearfoot of the orthotic to allow the orthotic to hold someone’s foot in a neutral position. The amount of posting varies from patient to patient depending on where the overpronation (or areas of flattened arches) occurs in the foot.
Once the length, width, top-cover and posting have been decided on, there may be additions and modifications that need to be made to the basic shell depending on your biomechanical faults and medical issues. The lab that the physiotherapists at Rebalance Sports Medicine use is the largest orthotic lab in Canada. They offer 25 different additions and modifications for orthotics. Some of the more common additions/modifications are metatarsal pads (used to promote a transverse arch), a full heel cushion (for plantar fasciitis and heel spurs) and a reverse Morton’s extension (for bunions and 1st MTP osteoarthritis).
Perhaps the most important thing when deciding to get a custom made orthotic is to find a good practitioner. In Canada, orthotics can be prescribed and dispensed by Podiatrists, Chiropodists, Sports Medicine Doctors, Physiotherapists and Chiropractors. Whoever you choose to see needs to have sound knowledge of anatomy, the biomechanics of gait and sound knowledge of orthotics. Of course, years of experience help too.