What is the difference between an Orthotic and an Arch Support?

Most people would reply the terms are interchangeable. But to Physical Therapists, as well as Podiatrists and others in the medical field, the differences are significant.

An arch support is aptly named – it provides a generic “one size fits all” level of support to the arch of your foot. That’s usually not a bad thing and sometimes it’s good enough. The best thing about arch supports relative to orthotics is that they’re pretty easy to get your hands on, and they aren’t that expensive. The better arch supports usually only cost $30 or $40.

So what is an orthotic?

Orthotics are custom made devices that not only also provide support to your arch, but they also address any biomechanical faults you may have. In many instances the faults may be the culprit behind the lack of arch support. The process begins by measuring your foot to see how it is deviates from an ideal foot. Then the orthotic will be made to help compensate for your foot’s deviations from ideal. The orthotic will help your feet interact better with the ground, which in turn may also help your knee, hip and/or low back. However, because they are custom made, acquiring them can be laborious. First, an evaluation by a medical professional is required. Second, it takes a few weeks for the orthotics to be made. And perhaps the biggest deterrent is the higher price tag (although insurance may cover some or all of the cost).

For readers whose curiosity has been satisfied, what you’ve read will suffice. For those of you that are still tickling to know a bit more detail, keep reading!

So what is a biomechanical fault, since it seems to be a determining factor between picking an arch support or an orthotic? By definition it means having an imbalance in your body that affects how your body functions both at rest and during movement. Examples include one leg being significantly longer than the other; a muscle on one side of a bone or joint is shorter than normal and the opposing muscle on the other side is longer than normal; or a vertebrae being rotated, flexed or side-bent. Biomechanical faults can involve bones or soft tissue (muscle, ligament, tendon…) and can be congenital or acquired. In short, they can exist for many reasons from numerous sources. For our purposes we’ll skip the “where is it coming from” aspect of biomechanical faults for now and just accept that sometimes they exist in soft tissue and bones.

Typical biomechanical faults in the foot include rearfoot varus and forefoot varus. These faults can be detected while you are lying down on your stomach. With your body in a neutral position, your rearfoot (the heel) and/or your forefoot (from the front of your arch forward) will be “turned in”.

Here are some photos to demonstrate. The pictures involve a Physical Therapist forcing a models foot into the various positions, for demonstrations sake.

Forefoot Varus, orthotic, arch support
Neutral Rearfoot, orthotic, arch support
Rearfoot Varus, orthotic, arch support

​​​On a side note, the “neutral” mentioned above specifically refers to the position of a small bone in your ankle (the talus). We adjust the talus until it’s in a balanced, or neutral, position. Then we look at the alignment of the rearfoot, forefoot and a host of other things while your talus is in a neutral position to ensure accurate diagnosis. Check out our video of a therapist finding “sub-talar neutral”.

​​​​​​​OK, back to you, on your stomach. So let’s say you have rearfoot and forefoot varus while you’re lying down. What happens when you stand up? Imagine I am super strong (with great emphasize on “imagine”) and I lift you off the table by your shoulders and hold you upright in mid-air like a sheet of fresh linen. As I slowly lowered you to the ground, which part of your feet would hit the ground first? With rearfoot and forefoot varus, the outside border of your feet will hit the ground first. As I continued to lower you, the rest of your foot will gradually roll in until your whole foot reached the ground. If you are picturing this correctly, you will notice that your arch has come closer to the ground than is ideal. 


Essentially, this would mean the feet rolling in, the legs turning in, the pelvis tilting, and the back increasing its lordosis. A whopping four compensations (to name a few) have occurred due to your rearfoot and/or forefoot varus. But before you panic and run screaming for a doctor, keep in mind that whether to address them needs to be evaluated on a case-by-case basis. Perhaps you aren’t having any pain and are functioning just fine – if it isn’t broke, should you fix it? Or if you are having pain and/or aren’t functioning as well as you’d like, are these findings the cause of your pain/poor function. Put another way: are your faults and compensations correlated with problems you are having, or are they the cause? Or is it just a coincidence? I like to call this process of comparing your symptoms and functions to our objective findings “The 3-C’s”: Are these findings merely coincidental, do they simply correlate, or are we certain that they are causative. Sometimes it’s hard to tell, but if we’re fairly certain it’s a cause, addressing them is often a wise choice.

So how does an orthotic work? It might help explain things by using an example.

Bridges with arches make a good analogy. Here is a link to a drawing of an “arch bridge”. Take a look! If the arch of this bridge starts to collapse a little, construction workers can insert something to fill the gap where the collapsing takes place. However, if the problem worsens to the point where the arch falls, the repairs created by brilliant engineers will be more sophisticated. Their repair will entail correcting the alignment of the keystones-- the bricks at the bottom and inside of both sides of the arch. If the keystones start to “collapse in,” it will cause the arch to fall. Therefore by correcting the alignment of the keystones it addresses the root of the collapsing problem.

Now shifting gears to your feet. An arch support would be the equivalent of the construction worker’s fix: it will simply push the arch of the feet back up as it collapses. It may fix it if it is minor. The keystones of your foot are equivalent to your rearfoot and forefoot. If you have rearfoot and/or forefoot varus, your keystones are in effect turned in when you are not on your feet and are turned out with your arch falling (inward?) when you stand. An orthotic will bring the ground up to the rearfoot and/or forefoot by filling the gap that exists so that it isn’t weight bearing. As a result, when you stand up wearing your orthotics your rearfoot and forefoot will stay neutral and you won’t be compensating –you have outsourced it to your orthotics. It correctly realigned your keystones. Sometimes it isn’t possible to get a complete correction, but a partial correction is often sufficient. Furthermore, some professionals believe that your body still compensates, but you compensate more slowly, which is better than compensating quickly.

Now the question is, do you need an arch support or an orthotic? Perhaps you should just leave it alone? Or take a different route and get some hands-on treatment and/or exercise to address the imbalances? How about going the opposite direction and join the trend of running barefoot? As my mom would say, there is a time and a place for everything. Without seeing your feet, we can’t really say. But when you do make a decision, it will be informed and the best option for your two standing bridges. If you decide to see a medical professional for advice, hopefully this helps you better understand what they’re looking for and assists your ability to communicate more effectively with them.

We'd be happy to work with you and tell you which is right for you. If you think an arch support will do the job - or you simply want to give one a try as an easy and relatively low cost option, here are the arch supports we recommend. The flatter your arch is the more likely you'll want firm, but it also means it's more likely that will take some getting used to. In addition, please keep in mind that the more substantial (or firm) the arch support or orthotic is, the more space it will occupy in your shoe. So when in doubt opt for Medium Firm or Gentle.