By Dr. Scott Colasanti
The American Podiatric Medical Association states that the average person takes 8000 to 10 000 steps per day, which amounts to about 115 000 miles in a lifetime. To put this number in perspective, that is more than 4 times the circumference of the globe!
Consider Newton’s third law which states that for every action there is an equal and opposite reaction. As far as our bodies are concerned, this means that the force that we exert on the ground, i.e. our weight (action), is equally exerted back to us (reaction). This is also referred to as ground reaction force.
In a 150lb human walking 10000 steps per day, that is a lot of force!
You may glean a better appreciation of what our bodies our capable from these factoids:
- Our feet contain 52 bones and make up one quarter of the bones in our body.
- There are 33 joints and more than 100 muscles, tendons and ligaments in each foot and ankle.
- These bones, joints, muscles, tendons and ligaments are the foundation for the rest of our body and they are designed not only to help us walk and run but also to keep our bodies in balance.
- There are an astounding number of sensory nerves in our feet that process information from our environment. This information is coordinated by the nervous system in a way that is so seamless that we don’t have to consciously think about it. This ability is known as proprioception or our position sense.
Have you ever walked down a set of stairs only to think that you were on the ground when in fact there was one more step? What happens next is often a jarring realization that our perception is not coordinated to the reality. We take for granted the complexity and the roles that our feet play on our bodies.
Considering the fact that majority of time we spend on our feet is on hard surfaces like concrete, ceramic, and hardwood, not to mention that many of us are choosing our foot wear that is constrictive to the normal biomechanics of our feet, it is no wonder that 90% of the population has some sort of foot dysfunction, or problem related to the biomechanics of the feet and the impact that may have on the body. Keep in mind that our bodies are wonderfully designed to minimize and divert those ground reaction forces, however when we lose some of those abilities those forces are now imposed on our knees, hips, back, etc. It is then easy to see how feet have an impact on the rest of your body.
So what are orthotics and how can they help?
First of all it is important to note that there is a difference between insoles and orthotics. Insoles are simply shock absorbing material fitted to your shoes. They are neither corrective nor specific to the individual. Orthotics may look like insoles but orthotics are actually biomechanical medical appliances that are custom made to correct your specific foot dysfunctions. They reduce the stress on your body by helping your feet function more properly. I like to compare them with eyeglasses in that eyeglasses are corrective to the dysfunctions that affect our ability to see. They are specific to the individual. Have you ever tried to wear someone else’s prescription eyeglasses?
Orthotics are made by performing a biomechanical gait analysis which looks at foot function and any specific deformities, as well as the functional biomechanics of the body in general. After this a cast or some form of impression of the foot is made and the orthotics are then constructed based on all of this information.
The goal of wearing orthotics is to reduce stress on the feet and body by providing biomechanical correction and shock absorption. Of course, wearing good footwear helps too. It is also important to note that we don’t have to have foot pain or deformities like heel spurs, bunions, or flat feet for there to be a problem. Often the symptoms of may manifest as knee pain or back pain, or even headaches. (Remember the ground reaction forces?)
We wouldn’t think of driving our cars thousands of miles without good tires. We should at the very least treat our feet the same way.