The old adage for purchasing shoes was based on:
- Arch Type
- Pronation
- Common Trends
Though there is no research to support that these three components reduce injury risk in a runner or allow them to run faster. And yet, for some reason, consumers continue to hold onto this train of thought when purchasing running shoes. In more recent years, terms such as drop, stack, cushion, motion control and stability have all surfaced within the industry with the same promises to keep a runner healthy while allowing them to run faster. Let’s take a closer look at what holds merit when selecting your running shoe.
Motion Control
Motion control has been a catchphrase in the running shoe industry for years with the purpose of convincing the consumer that pronation is bad. Let’s take a closer look at what motion control shoes entail, their purpose and their caveats.
In order to control motion, shoe companies have created a denser material on the inside of the shoe to stop it from moving too much. This dense material, known as posting, is an attempt to control the lateral heel flare of running. This posting is located in the rearfoot of the shoe on the medial side. Do note, however, the majority of foot pronation occurs after the heel has left the ground. This design can be counterintuitive in the fact that its mechanism isn’t able to effectively control the motion of the foot since the rearfoot is not in contact with the ground at its maximum phase of pronation.
Secondly, pronation is not necessarily a bad thing. The natural mechanics of the foot pronation serves to absorb shock and attenuate loading forces. This action also allows the forefoot contact with the ground for a controlled stance phase of running.
Another thing we must consider with motion control, or medial posting, is the response upstream. By increasing the density on the inside of the shoe, this changes the runner’s contact point with the ground, creating more stress to the inside of the knee. If experiencing medial knee pain, it’s greatly advised to stay away from medial posting.
It’s the job of your foot’s muscles, tendons and ligaments to provide dynamic support and controlled motion of the foot – not a shoe’s. Active stability training should be a staple in any program for an athlete who feels a motion control shoe may be of benefit to reduce injury.
Cushion
As mentioned earlier, one of the most reliable ways to sell a shoe is based on current trends. In today’s shoe culture, cushioning is a rather prominent trend. Though it sounds ideal, the thought of running on clouds is synonymous with taking foot-strategy out of running.
Overly cushioned shoes are marketed to absorb the load and lessen the work of the foot. Sounds great in theory, until your foot can no longer do its job due to weakening of the muscles and lessened input from the nervous system. The pain from less-than-ideal running circumstances will show up somewhere whether it’s the back, knee, hips, etc.
Our foot is our direct line of communication with the ground. It works best when it has a good awareness of its position and is receiving sensory information. We need that information to be relayed quickly, and overly cushioned materials don’t allow for this feedback. If the foot is unstable, imagine how the body structures upstream are feeling. Less stability all around which equals less feedback, less muscle activity, and less control.
Now, there can be some merit for these maximum cushion shoes. They can act as a rocker from the heel to forefoot for an athlete with joint mobility limitations in the great toe and ankle. We need a certain degree of motion through the ankle and big toe to run appropriately. If this is lacking and unable to be achieved, (maybe due to a past surgery which included a joint fusion,) a shoe that provides extra rocking will aid in toe-off for the athlete.
Toe Box
Before your next run or shoe purchase, a simple way to understand if your shoe is right for you is to remove the insole and stand on it. The insole should be wide enough to encapsulate the entire foot without any overflow. Too often athletes are placed in a narrow shoe which throws off the mechanics of the foot.
We have a muscle in our foot, whose goal is to pull the great toe towards the midline of our body, to improve the leverage of the foot and provide support for the medial arch. If the foot is in a shoe that is too narrow, it will reduce the leverage we need to run. Also note, toe splay is important for leverage, as we want as much surface area as possible to absorb the loads running places on the body. Imagine trying to build a house on too narrow of a foundation. That wouldn’t work so well, would it? We should never ask our foot to function in a non-optimal foot splay.
Too narrow of a shoe can be a causative factor behind neuromas, plantar fasciitis and metatarsalgia.
Drop
The drop of a shoe is the height difference between the rearfoot and forefoot. Drop can be quite large, up to 12mm. A great analogy to visual drop is to imagine running in a pair of stilettos. This overdeveloped heel does a few things to running mechanics as it increases the runner’s tendency to overstride. Landing with an outstretched leg far in front of the body can compromise run form and economy as well as exacerbate issues such as runner’s knee, shin splints, tibial plateau fracture, compartment syndrome, knee osteoarthritis.
Other Considerations
A few other factors to be aware of when purchasing your shoes are initial comfort, the weight of the shoe and time of purchase. It’s easy to prove that, like anything else, when there’s a positive first impression, we are more likely to pursue it. Instant comfort is an initial buy-in for a consumer. You want your shoe to be comfortable, of course. Next, be conscious of when you try your shoes on. Our feet will swell throughout the day or after a training session. Purchasing shoes at the end of the day may be an optimal time to get a true reflection of your foot anatomy and specific needs.
In conclusion, to allow optimal function of the foot, choose a shoe with a wide toe box, as little cushion as your body can handle and a firm, yet light, construction. Avoid footwear with a pronatory flare unless instructed otherwise by a licensed practitioner. Allow the foot to do its job. Healthy running isn’t the job of a shoe, rather the role of the foot inside of your shoe. As supported by our evidence, spend time improving your body rather than shopping for shoes.
