One of the most common questions I hear in my clinical practice, as well as from family and friends is what type of shoe should I buy? Follow up questions ensue: Do I need to get my foot evaluated? Can I trust the advice of the running store employee? Should I use that machine that tells me my foot type?
Every running shoe store has a display spanning the show room that exhibits different categories of shoes. Motion control, stability, neutral, cushioned – knowing what type of shoe you need seems to have become very complicated. How did we get here?
The first rubber soled athletic shoe arrived on scene in 1832, though very different from what we consider athletic today. By 1895 we had the first running shoe, designed by the company we now know as Reebok. This shoe featured spikes to help with grip. In 1912 running shoes looked more like what our dress shoes might look like today. The picture below shows a running shoe from that time designed by Spalding.By 1916 we had something that might seem a bit more reasonable by today's standards – keds. They had a flexible sole with a tread, but no cushioning. It wasn't until the 1960's and 70's that we started to see the modern cushioned running shoe.The 70's in particular were a turning point.
A few critical things happened in the 70's. The first was that running starting to become a widespread sport. As running became more popular running injuries also started to become more commonplace. Scientific journals began to publish studies regarding these injury rates and even Runner's World Magazine, a relatively new magazine at the time, published an injury survey in 1971. Naturally, the search for a solution began. Nike in particular began collaborating with sports podiatrists to improve shoe design.
Since then we have seen significant technological advancement in shoe design as a means to decrease running injuries. The problem is running injuries are on the rise, with knee injuries being the most common. In 1971 17.9% of all runners sustained knee injuries, and in 2002 that number was up to 42%. So what happened? Shouldn't injuries rates have gone down?
Everything changed in the 1970's
Before the running boom of the 70's podiatrists studied a number of factors that were thought might be associated with running injuries. These 2 factors in particular, happen to be the most commonly studied
- Foot pronation
- Impact forces when landing on the heel during foot strike
So when the biomechanists came along and saw that these 2 factors were all the rage, they rolled with it. They assumed, without any epidemiological evidence, that foot pronation and impact forces were the main variables responsible for the development of running injuries.
So where does this leave us? We now have hundreds of models of shoes to choose from that range in the support they provide to either limit foot pronation or increase heel cushioning to reduce impact forces during running. The thing is that until recently no one really studied if providing this type of support actually reduced injuries.
Current Shoe Technology
The general premise that we have been working with over the last 40 years is based on 3 classifications.
Cushioning: This type of shoe is made for the person with high foot arches and a relatively stiff foot. The idea is to put a lot of cushion in the heel so that when your heel hits the ground less force is transmitted up the leg causing less damage over time. When you step out of the shower your footprint would look like foot A below.
Stability: This type of shoe is made for the person with the 'normal' foot. They have some cushion and some support. You can think of this as the happy medium. When you step out of the shower your footprint would look like foot C below.
Motion Control: This type of shoe is made for the person who has flat feet. This shoe provides support via a stiffer heel and denser material in the arch of the shoe.The idea here is that as your weight shifts on to one foot during running, the supportive shape of the shoe keeps your foot in an ideal position.When you step out of the shower your footprint would look like B below.
These classifications have had a major impact on how we fit people with shoes. This is how every major running shoe company brands their shoes, how podiatrists fit their patients, how military recruits decide what to wear for training and how long distance runners decide what to log their miles in. This all sounds good in theory, but in real life studies show that up to 79% of modern runners are injured in a given year.
So why have injuries increased?
There are some other factors that need to be considered to understand why running injuries have increased.
- 1.How we track injury has changed
- Before the 70's we didn't have injury reports for long distance runners. Is this because no one was tracking it? Or is it because there wasn't a high incidence of injury?
- 2.The running population has changed.
Today it's not uncommon to see a novice runner struggling to complete a marathon in order to check it off their bucket list. This didn't really happen before the 70's. Runners back then trained for years at a higher intensity and lower mileage compared to what we see today. Compare this to a novice runner who follows a couch to 10K program. This means that runners today are running longer distances while under-trained and unfit. This is the perfect storm for injury.
- 3.It might just come down to terminology
- There isn't really a standard definition of a 'running injury.' Which means when we analyze studies across decades we might not be comparing apples to apples. This makes it hard to follow a logical progression over time.
Where's the evidence?
Luckily the research is starting to catch up to the world of footwear and we're starting to see more and more studies trying to answer the question: Can picking the right shoe reduce injury rates?
In conclusion it seems that as the popularity of running has increased so has injury. The question is how do shoes fit into the equation? Shoes have become more high tech but injury rates have increased sharply. How do you as a runner navigate through this world of shoes? And what gives you the best chance of staying injury free?
We'll delve deeper into this topic next post where we'll discuss what the current research is saying and what you can do to pick the right shoe.
Davis, IS. (2014) The re-emergence of the minimal running shoe. JOSPT. Vol. 44(10), p775-784
Knapik, JJ., Trone, DW., Tchandja, J., Jones, BH. (2014) Injury reduction effectiveness of prescribing running shoes on the basis of foot height: Summary of military investigations. JOSPT. Vol. 44(10) p805-812
Nigg, BM., Baltich, J., Hoerzer, S., Enders, H. (2015) Running shoes and running injuries: mythbusting and a proposal for two new paradigms: 'preferred movement path' and 'comfort filter'. BJSM. Vol. 49, p1290 – 1294