What is an Orthotic?

You will see and hear the word, orthotic being used loosely, especially in the retail market. The retail world is using the word orthotic to describe any type of shoe insert or arch support. My definition of an orthotic is a true prescription durable medical device designed to treat foot, ankle or gate abnormalities. This is a device that is custom made by a healthcare provider, most commonly a doctor of podiatric medicine or podiatrist.

Orthotics can be used to help correct abnormal walking patterns, absorb shock, improve balance, reduce pressure or sore spots or help with distribution across the entire planter surface of the foot. Basically, an orthotic helps to reduce abnormal or excessive motion while supporting the normal motions of the lower extremity.

There are many different types of orthotics. The type of orthotic that I primarily use is called a functional foot orthotic. This is a device that will go underneath your foot and simply slides into most conventional shoes and is primarily used to treat foot problems. Another type of orthotic is called an ankle foot orthotic. This has a similar orthotic plate underneath the foot, but also has supportive bracing going halfway up the leg. This is a more controlling orthotic that is used to treat more significant foot, ankle and lower extremity disorders.

How is an orthotic made? There are many different techniques to create an orthotic. The first step is to create an impression of the foot or lower extremity. One method is to use a foam box. This is where a patient will simply imprint their foot into a foam box in a partial weight-bearing situation. In my opinion this is not the most ideal for a true custom functional device. Another technique is to use wet plaster. Wet plaster sheets are placed around each foot. The foot is then held in a neutral position until the plaster dries. The plaster molds are taken off the foot and those are sent to the lab. Another technique is an electronic scanner. Kind of like a copy machine where the foot impression is copied with a scanner and that information is digitally sent to the lab. The technique that I use is a three-dimensional scan using lidar software. This technique in my opinion is the most accurate and dependable and can be done directly from an iPhone. The next step in manufacturing an orthotic is sending the foot impression along with a very detailed prescription to an orthotic lab. With a standard orthotic prescription, I answer anywhere from 50 to 75 different questions regarding the condition of the foot taking into consideration, bodyweight, shoe size, activity level, pathology and shoe type. The prescription is developed specifically for that individual’s pathology. Once the prescription is done and impressions have been sent, the lab will manufacture the orthotic. Most labs take anywhere from 2 to 4 weeks to manufacturer an orthotic and get it sent back to my office. It’s now time to fit the orthotic into the patient shoe. We have the patient bring a shoe that they will most likely use the orthotic. The existing insoles are removed and used to trace the new orthotic to make sure it fits perfectly into the patient shoe. The orthotic is placed into the patient shoe. Patient will then try on the orthotic in the office. We do recommend a slow break in period. We recommend the patient only wear the orthotic one hour the first day, two hours the second day, three hours the third day and so on. Usually within two weeks, most patients will not even feel the orthotic under their foot while it’s in the shoe.

Some of my most common reasons to prescribe a custom-made orthotic.

1. Flat feet or what we call pes planus. A flat foot is where an arch lowers excessively during gate. The foot is made of 26 bones and these bones are designed to stay within a normal shape, even with weight-bearing. With a flat foot, again this arch becomes too low, unlocking those 26 bones causing an unstable foot. I refer to this unstable foot as a “bag of bones”. When we walk and push off, we benefit from a rigid device at the bottom of our leg to create stability. With an unstable or flattened foot this rigid scenario that we count on is no longer there, which then ultimately necessitates over recruiting the lower extremity muscles, tendons, and ligaments.
2. High Arch or Pes Cavus. A high arch foot I always refer to as, the tripod foot. Most of the pressure delivered through the foot ends up going through two or three points on the bottom of the foot. Patient with a higher arch foot greatly benefits from an orthotic that can match the entire bottom surface of the foot from heel to toe. This will enable weight to be distributed evenly from heel to toe instead of those two or three high pressure points. This type of orthotic does not necessarily need to be a rigid device. It can be a semi-flexible device made from soft materials as long as there is good contact or purchase with the entire planter service of the foot.
3. Achilles tendinitis or Achilles tendinosis. The Achilles tendon is the largest and most powerful tendon in the body, and when it gets inflamed, it becomes very challenging to treat. Under using the Achilles tendon to rest and heal it is an important part of treating these problems. An orthotic reduces excessive motion of the foot thereby resting the Achilles tendon. I also typically add a small lift to the orthotic which will raise the heel 2 to 3 mm during weight-bearing, which can relax or take tension off the Achilles tendon.
4. Hallux limitus with osteoarthritis. Hallux limitus is a condition of the big toe joint. Hallux is the medical term for big toe and limitus meaning limited motion of the big toe. One of the main causes or drivers of hallux limitus is a flat foot. When the arch lowers this will cause a change in position of the first metatarsal and a change, in how the big toe joint can function, this causes abnormal force going through the big toe joint, which can lead to degenerative arthritis. Orthotics can greatly benefit hallux limitus by stabilizing the arch and helping maintain the relationship of the big toe joint and by adding an extension within the orthotic device called a reverse Morton’s extension this can help return motion to the big toe joint. A reverse morton’s extension allows the first metatarsal to sit lower than the second, third, fourth or fifth during stance and gate and again this will allow increased motion of that big toe joint.

In conclusion, a custom orthotic is a powerful tool in addressing a variety of foot and lower extremity issues, from flat feet to high arches and conditions like Achilles tendinitis and hallux limitus. Unlike generic, over-the-counter inserts, custom orthotics are specifically designed to fit the unique needs of each patient, providing tailored support and correction. Look for shoes that have a removable insole for optimal use of your orthotics.

Written by Jeffrey Hurless, DPM

Written by
Dr. Jeffrey S. Hurless
DPM, FACFAS Board Certified Foot & Ankle Surgeon/Podiatrist
Medical Director, HealthyFeetStore.com