The famous machine engineer, Franz Reuleaux, is attributed with being the father of kinematics. In 1875, he suggested that the movement of one part of a machine had an effect on other parts of the machine by conveying force through the various joints of the machine. This concept was adapted and applied to the human body in the 1990s and included the analysis of human movement during different activities.
The concept of the human kinetic chain was born which had applications to many specialties including orthotics. So in part, the question we’re interested in, is if you can modify the impact of the foot on the ground creating force that travels through the human kinetic chain, can it lead to improved performance and reduced injury?
This is the fundamental principle on which orthotics is based on. Does it really work and is it really worth it? In this article, we will cut through the sales pitch and get to the heart of the science one step at a time.
What Is Orthotics?
An orthotic is a device that serves to support, manipulate, or align a moving part of the body such as the foot. In the context of shoes, orthotics can be custom made inserts for the shoe or some addition to the sole of the shoe. The basic idea is that the orthotic will help prevent movements that are contributing to pain and injury.
The clinical assessment of how you walk (gait analysis), your medical history, and assessments involving medical imaging like X-ray are all part of the medical branch called Orthotics.
Keep in Step With Science
Let’s start with the concept of pronation. This is the name given to the normal natural movement of your foot as you move through your step.
In the normal step, there’s a slight rolling motion from the inner edge of your foot towards the outer edge. Your big toe and second toe provide a degree of drive-through while your remaining toes tend to stabilize and spread the force of your movement across the undersurface of your foot.
Over-pronation occurs when your ankle maneuvers inward shifting the full force onto your big toe and second toe while minimizing the spread of force to the remaining toes.
Technically this is called supination. In this case, the position of the ankles shifts the load onto the outer edge of the foot before movement. That means when you take a step, the normal rolling motion is minimized and it also reduces the role of your big toe and second toe in the overall movement.
Early orthotics followed the idea that you could build up the step in the shoe so that it corrected for abnormal pronation described above. This would ‘re-align’ the movement of the foot and promote normal pronation. Did this work?
Anecdotally yes. Many in the industry reported success with this approach. However, when it came to producing hard quantitative data the problem was that researchers couldn’t see a clear difference in the way users moved when wearing the orthotic.
Bottom line: a clear causal relationship between pronation and injury could not be established. Mix research results have further added to a lack of clarity as to the ‘measurable’ benefit of using orthotics.
Preferred Motion Path
In a landmark paper by Beno Nigg, it was proposed that the movement of various joints follows a preferred motion path. This is likely determined by many factors such as muscle strength, the physical dimensions of the joint as well as learned movement patterns from exercise, and other activities.
Ultimately if an orthotic supports the preferred motion path then the overall outcome is positive. If, however, it opposes or impedes the normal path of motion the orthotic only adds to the problem as it forces inadequate compensatory mechanisms along the kinetic chain.
The same study mentioned above involved offering subjects the choice of whatever orthotic they thought was most comfortable. They reported a lower injury incidence when compared with the control group.
Orthotics have a mixed review from users. It seems some people really get on with them and feel like they benefit while others are convinced it’s a complete waste of money. With such mixed and strong feelings, it can be hard to make sense of it all.
Ultimately the research seems to support the idea that the most important guiding principle in choosing an orthotic is not that it ‘correct’ pronation or some other defect but that it enhances wearing comfort. If you do pursue an orthotic it’s wise to keep that thought in mind.
Are Orthotics Worth It?
Some people may especially benefit from using orthotics because of a medical condition. For example, people with diabetes suffer from poor circulation in their feet and orthotics can assist with this. Also, in some cases where patients have arthritis, it can cause significant deformities, and using normal footwear can very uncomfortable.
However, in the majority of people, other alternatives may be as effective or even more effective. Before spending a fortune on an orthotic examination and footwear you would be well served by exploring insole options first as they can make a big difference to comfort, and remember, that is what seems to be important to avoiding injury.
That said one of the best things you can do is make sure you buy the right shoes that are the right size for your feet. Some of the best running shoes for orthotics can also be fitted with custom insoles or other off the shelf products that can create an excellent fit.
In summary, the science behind orthotics is mixed without a clear measurable benefit for most users. That said as long as the orthotic adds to comfort when using it, then you will likely benefit in a qualitative way. Before shelling out hundreds of dollars make sure you try many other basic and cheaper alternatives like insoles.
Don’t forget as you get older your feet also can change their size and shape, so get them measured before you buy your next pair of shoes. Well-fitted shoes will go a long way. Check out the other recent posts on our site that will keep you in awe of what life has to offer.