Although very few overuse running injuries have an established aetiology, the fact that over 80% of these injuries occur at or below the knee suggests that there may be some common mechanisms. The capacity to prevent such injuries is currently limited, with training advice and footwear prescription forming the mainstays. Thus, the prescription of the correct running shoe is considered a crucial and highly valued skill. Unfortunately, in a study in which runners were randomized to receive a neutral, stability or motion control running shoe, it was reported that prescribing motion control shoes incorrectly, without proper justification or rationale, is potentially injurious. So what is the science behind fitting a runner with the proper shoe?
First, let’s discuss the different categories of footwear. Overall, there are three categories of footwear: neutral, stability, and motion control. A neutral running shoe is designed to provide cushioning and less foot control as compared to its motion control counterpart. A stability shoe has some component of pronation control material and that material is generally placed near the middle or arch of the shoe. A motion control shoe typically has a significant amount of pronation control material and often has some type of non-deformable material, such as a plastic plug, placed on the back-outside edge of the shoe.
Any method used to properly match up the proper shoe to each runner is generally based on either optimizing performance or reducing the potential for injury. Overall, very few studies have been published and the results have shown that running in the three different types of shoes does not produce a consistent change in foot, ankle, or leg running biomechanics but rather small and individualized changes. In other words, just changing the shoe does little to influence how well you run and perform. Moreover, a large military study showed that the prescription of footwear based on plantar shape, a method analogous to the wet test, found no reduction in injuries between the treatment group and control group during basic training. So where does that leave you?
First, its important to understand that previous research has involved very simplistic methods for trying to correctly match footwear with each athlete. The ‘wet test’ mentioned has no scientific validity. Even using a single video camera and video taping you running on a treadmill has no scientific validity. Many research studies, dating back to 1995, have reported up to 200% error when trying to measure biomechanical angles using a single camera as compared to the gold standard of 3D motion capture. Two of our recent research studies verify these findings and demonstrates a 20%-140% over-estimation in foot pronation angle when using a single camera. So don’t be fooled by running stores that advertise “high-tech” approaches to shoe fitting by videotaping you on a treadmill. So what should you look for? If a store only uses one method, even if it is high-tech, to determine what shoe might be best for you, go somewhere else.
You should look for a running store that uses comprehensive approach to determine the correct shoe for you. I’ve actually been a fan of how the Running Room approaches shoe fitting for quite some time — and I don’t say that on account of them letting me write an article for this magazine! Certainly the decision-making process we use at the Running Injury Clinic is based on 7 years of research and utilizes state-of-the-art equipment; but its quite similar and actually modeled after the Running Room approach. Many factors are taken into consideration: standing posture, biomechanical movement patterns, functional tests (i.e. the lunge), wear patterns on your current shoes, and how comfortable you find your current shoes. All of those pieces are put together to formulate a decision about what type of shoe will be best for you.
Finally, there are some good research studies strongly suggesting that the more comfortable you perceive a shoe to be, the better you’ll run in them; regardless of the type — neutral, stability, or motion control. So trust your instincts and find a shoe that feels good. First let the shoe store employee guide you to the correct type, using a comprehensive analysis, then choose the most comfortable shoe. Happy running!