Clinical Biomechanics for Podiatry (Post #2): Foot Orthotic Devices: General Principles

There are many types of foot orthotic devices for the consumer. They fall into 5 categories based on the needs of the patient. These 5 categories are:

1. Corrective (or Controlling)
2. Stabilizing (or Balancing)
3. Shock Absorbing (or Cushioning)
4. Accommodative (or Weight Transferring)
5. Combination (or Multi-Functional)

How is the correct orthotic device ordered or purchased? The orthotic device that you prescribe, or that you recommend purchasing in a store, may or may not help if it is not the correct type. At its best, the correct orthotic device will successfully make the necessary change in mechanics, but it may still be crucial to work on all the other aspects of rehabilitation (anti-inflammatory, flexibility, strengthening, etc.) in order to relieve all your symptoms. It is important when prescribing the orthotic device that you are familiar with the many different types of orthotic devices available. It is also important for the patient/customer to be somewhat clear on what type of orthotic device is needed. And, unfortunately, the type of orthotic device required today may change in the future with different sports, different symptoms, different shoe types, and different age. You need to be willing to change to a different type of orthotic device if the patient's symptoms are not improving with the present pair of orthotics, and if there is another type available that may help them. Sometimes, practitioners don’t like discussing this type of change due to the added cost to the patient, but it is important that they know there are options.

Corrective or Controlling Orthotic Devices do what they say---correct or control excessive pronation or supination (the inward collapse of the arch, or the outside roll of the ankle, respectively). This type of orthotic device produces the most dramatic change in function, and may take the most time to get used to wearing.

Stabilizing or Balancing Orthotic Devices normally do not change foot position much, but the patient/customer feels more centered, more balanced. The weight of any point can become so distributed that only a small fraction of the original weight bearing still exists. This can be vital for heel pain, some arch pain, fifth metatarsal base pain, and many metatarsal problems.

Shock Absorbing or Cushioning Orthotic Devices take the stress out of the pounding of heel impact. Runner’s versions need to have equal cushion at the heel and forefoot. These can dramatically reduce the stresses which cause or aggravate stress fractures, joint pains (knee and hip), and heel pain. One of the best shock absorbing orthotic devices is the Hannaford which will be discussed later.

Accommodative or Weight Transferring Orthotic Devices try to transfer weight from a painful area to a non-painful area. These orthotic devices have probably been around the longest of all orthotic devices prescribed by podiatrists. If you have heel pain, you need an orthotic device that transfers weight into the arch. If you have sesamoid pain, you need an orthotic to transfer weight back into the arch and onto the 2nd and 3rd metatarsal heads.

Combination or Multi-Functional Orthotic Devices are probably the most prescribed type of orthotic device. The prescribing practitioner attempts to accomplish multiple tasks with one type of orthotic device. This is why there are so many types of orthotic devices out there. When you really study them, most primarily do one of the 4 basic functions really well, and then 1 to 3 of the other functions somewhat or not at all. A good practitioner will try to get the most out of orthotic therapy. This means that the practitioner tries to combine different functions into each orthotic device on a routine basis. Sometimes, however, doing too much sacrificing the most important function.

Hopefully, this post helped you understand some of the basics of orthotic therapy. When discussing with a patient, try to understand what we want the orthotic device to do. Ask yourself these questions:

1. Do I need to order a corrective device to change foot positioning?
2. Does the patient primarily need to feel more centered and stable?
3. Do they need cushion/shock absorption as they walk or run?
4. Do they need to transfer weight from a painful area to a non-painful area?
5. Do they need a multi-purpose orthotic device with many functions to help the problems at hand?

Perhaps the patient will need several orthotic versions since their activities, shoe gear, etc. vary so much. The doctor and patient must be on the same relative page, and the patient must be aware that there may be a plan B.