Cushioning has been a highly debated topic and point of emphasis for many running shoe brands over the last 15-20 years. But are the most cushioned running shoes the right choice for you?

In 2000, Nike released their Shox line, which incorporated four spring-like columns to reduce jarring to the body. In 2005, we saw the release of Vibram Five Finger shoes and the start of the barefoot and minimalist shoe craze. Then in 2009, Hoka released their first shoe, which swung the pendulum completely in the other direction with the advent of the “maximalist” shoe with excess cushioning.

Within all these radical changes, even conventional running shoes have undergone dramatic changes to their cushioning and midsole technology. 

Shoe companies – and runners – are most interested in two primary goals:

As a physical therapist, I’d like to focus on what the research says when it comes to injury rates and prevention. Specifically, how does increased cushioning either reduce or increase the prevalence of injury for an average runner?

The primary way to reduce the likelihood of injury is to minimize Ground Reaction Force. This adage is widely accepted among runners, coaches, and physical therapists alike.

Ground Reaction Force is exactly what it sounds like – the force exerted on a body that is in contact with the ground. So as your foot hits the pavement, the ground exerts a force on your body in several ways, including the initial peak and active peak.

The initial peak occurs as your foot contacts the ground. We tend to think of this as the “braking” period of the foot strike and occurs in all gait patterns to some extent, including forefoot runners. 

Many folks assume incorrectly that this is the maximum force being applied. However, active peak, or the second phase for all runners, is actually the greater regarding force. As shown in the graph below, this occurs as you are pushing off the ground. 

Generally speaking, the maximalist shoe group claims that in order to handle the stress involved with your foot interacting with the ground, you need maximum cushioning to reduce initial and peak forces. They believe more cushioning results in greater distribution of forces, ultimately reducing stress on the body system.

Like all studies, there are some details worth considering when trying to generalize the statement more broadly.

First, all the runners in this study were heel strikers. While the vast majority of runners are heel strikers, not all of us are.

Second, the study found that when running at slower speeds, defined at 6.2 mph, the variations in force between the two shoes was not as extreme. So, if you run closer to a 10-minute mile you may have a different result than if you run a 7-minute mile.  

One other potential issue with the study design is that participants were analyzed in the two shoes without any training or time running in the shoes first. It could be reasonably concluded that with time and training you would modify your running form and start to take advantage of the cushioning. 

So while the research is somewhat limited, we do see some consistency that maximalist shoes seem to increase ground reaction forces rather than decrease them.

In my work with patients, I have always reasoned that no matter how much cushioning you place under your foot, your body system still wants and needs feedback from the environment (the ground, in this case) to know how to respond. Placing more cushioning under the foot makes it harder to “feel” the ground, so the body thinks it needs to strike harder to get the same type of feedback.

The news is not all bad for maximalist shoes. We have discussed at length the impact these shoes have on ground reaction force which effects the entire body – foot, ankle, knee, hip, and low back. 

We have not discussed what happens more locally, specifically at the foot. A 2018 study found that maximalist shoes do reduce stress through the foot itself. These findings suggest that a maximalist shoe decreases plantar loading under the total foot and forefoot during running.

Certain runners may benefit from reducing pressures under the foot during running activities, even if the total system is undergoing more load. Identifying who those runners are still necessitates more research and consideration.

I firmly believe that comfort is a critical indicator of how well a shoe will work for you. Also, improving your strength, running mechanics, and running efficiency are also vital. 

The goal of this article is not to say maximum cushioning is the panacea for all runners or detrimental to all runners. While maximalist shoes have gained more popularity in recent years, be aware that the benefits advertised might not be true…for you. These shoes are certainly right for some of you out there, but please don’t go blindly down the path of the newest fads if the shoe isn’t comfortable when you put it on.

More research is needed to collect injury rates with all shoes, specifically maximalist shoes. Even though we know increased ground reaction forces will increase your likelihood of injury, there may be more nuance to that statement for individual runners. 

In future posts I’ll break down other factors including minimalist shoes and their injury rates, how foot strike pattern effects your loading rates, and concepts to help make you faster.

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