Introduction to Running Mechanics
Running mechanics is a fairly misunderstood topic among many coaches and athletes. There is a lot of misinformation out there on what is considered ‘proper running form’. Some of the most common recommendations I will often here from others is to ‘run with a cadence of >180 steps per minute’, or to ‘kick your heel to your butt when running’, or to ‘run on the ball of your foot’. These recommendations, and more, are incorrect and not based on the most up-to-date scientific literature.
There is an incredibly wide variance in running mechanics among amateurs and professionals, with differences in things like running cadence, arm carry, heel kick, etc. often being quite unique to each runner (6). Research in recent decades has shown that ‘proper running mechanics’ can be best summed up with the following three evidence-based recommendations (6):
Run with a slight forward lean at the ankles (not the hips),
Land with each foot strike under the hips, or the body’s center of gravity (heel vs. midfoot, vs. forefoot doesn’t matter), and
Run with a self-selected cadence that feels comfortable and natural (typically somewhere between 160-190 steps per minute)
The rest of running form and mechanics is up to each individual to self-select and optimize over time. Running technique and efficiency usually optimizes itself over time as a runner runs more and gains more experience.
Running Shod vs. Barefoot
Another hot topic of debate and one also fraught with misinformation is running footwear. Again, this is something that is highly individual to each runner to find what it best for them over time. Some runners prefer more ‘cushy’ shoes whereas others prefer more ‘minimalist’ shoes. Others prefer something in between. However, one aspect of running that is not debatable is the difference in running mechanics that occurs when a runner runs shod (i.e., in shoes) vs. barefoot. With any runner, there will be a difference in foot strike pattern, cadence, and other mechanics when going from shoes to no shoes (1-2,4-5), and this is not necessarily a good or bad thing. It is simply a matter of what is and what is observed.
I want to spend a bit more time discussing this last bit of information as it is important for endurance athletes and coaches to know what happens when someone goes from running shod to running barefoot.
Some runners are adamant that running barefoot is optimal, whereas others argue running in shoes is optimal. I’m not here to get into human evolution and how the foot has changed over time as humans have evolved. However, humans did indeed start off running barefoot through untouched wilderness over rocks, roots, stones, and more. We then progressed over hundreds of thousands of years to where we are today, which is running in various types of shoes on pavement, trails, and treadmills. Like just about anything else we experience in our day-to-day life today, running in modern day conditions is vastly different from the running conditions that humans experienced a long time ago. So I challenge folks to be careful when claiming what is ‘optimal’ when it comes to run footwear, or lack thereof, as humans have slowly adapted over time to do many things differently as the world and the environment we lived in has changed.
For example, barefoot running humans from the early days of our ancestors possibly had different foot structure and different thickness of padding on their feet. They also never knew what running in footwear was like and therefore acclimated over time to optimize themselves for running barefoot on wilderness terrain. Humans today, however, are born from generations of humans that have worn footwear of some sort. We also most likely started wearing shoes as soon as we could walk. So we more modern humans acclimated over time to optimize ourselves for walking and running shod and not barefoot.
The point is, just because early ancestors of ours did something a long time ago when the world was vastly different than it is today does not mean we should replicate it and that is optimal for today’s modernized conditions. After all, most people run on concrete and asphalt for goodness’ sake! Try running on those surfaces barefoot and see how your body feels the next day…
With that discussion out of the way. Let’s discuss what we know happens when an athlete transitions from running shod to barefoot. Typically, we see in the scientific literature that when an athlete goes from running in shoes to running barefoot, a few key running characteristics will change (1-2,4-5):
A greater tendency for a midfoot or forefoot strike,
A higher running cadence,
A shorter stride length,
A shorter ground contact time, and
A shorter flight time
These changes when going from shod to barefoot are not a good or bad thing like I mentioned previously. The loading patterns and shock absorption characteristics while running are different in shod vs. barefoot conditions, and running biomechanics will change to better suit the footwear conditions that a runner chooses. It is actually quite fascinating that the body is able to shift the way it runs without conscious thought when running shod vs. barefoot.
A recently published study by Jaen-Carillo and colleagues (3) aimed to examine differences between running shod vs. barefoot like many studies have in the recent decades, but they had study participants wear a Stryd foot pod that measured power while running. The findings of this study confirmed what we already see in the literature in that runners running barefoot tended to have more of a midfoot or forefoot strike, a higher running cadence, a shorter stride length, a shorter ground contact time, and a shorter flight time. However, researchers also identified a greater running efficiency when running barefoot compared to running in shoes as evidenced by lower form power (power output that does NOT generate forward propulsion), greater leg spring stiffness, and lower vertical oscillation in those running barefoot. These changes are indeed all good things that a runner tends to experience at a slower rate over time when running in normal shoe footwear. These changes are usually indicative of improvements in overall running efficiency.
Now, again, these differences do NOT mean that running barefoot is superior to running shoes because there are efficiency changes. For example, in this same study, the average power and normalized power output required to run at the pace study participants were running at during the experiment was no different between shod and barefoot groups. This essentially means that all runners, regardless of shod or barefoot condition, required the same power output to run at the given pace they were assigned. These differences are, however, important to know as an athlete or coach.
One reason it is important to know the differences in running shod vs. barefoot is so that clever marketing tactics can be assessed for validity. For example, minimalistic footwear companies and even some proponents of running barefoot will make wild claims about the so-called ‘superiority’ or ‘benefits’ of running in minimalistic footwear or of running barefoot. Most of the time, the claims that individuals and companies make are absolutely not grounded in scientific evidence and can be misleading for athletes and coaches. There have been minimalistic footwear companies in recent years that have actually gotten in trouble for making false claims about their shoes.
Another reason it is important to know the differences in running shod vs. barefoot is because there may be some potential benefit to purposely running barefoot on soft surfaces in small doses. Authors of the study I mentioned previously (3) called for more research examining the long-term impact of adding small bouts of barefoot running to an athletes training plan. The reasoning for running barefoot on soft surfaces (grass, turf, smooth trails) is that running barefoot forces running biomechanics that are more efficient in certain ways. If a runner can train barefoot occasionally, is there some long-term efficiency improvements to be had that can transfer over to running in the athlete’s normal footwear? Researchers don’t know as of yet, but hopefully future research will give us some more answers on this topic.
So what does this all mean?
What can be taken away from this discussion? First, know that running biomechanics and running form is highly unique to each individual. Rarely should there be specific changes to running form unless an athlete is running with a dramatic flaw or deficit in their form (landing way out in front of their center of gravity, running with an extremely low cadence <160 steps per minute, leaning really far backward or forward, bouncing up and down way too much with each run stride). Second, footwear is also highly unique to each individual. There is no one best shoe or barefoot running style that is best for every runner. Shoe choice should be made by each individual athlete that best suits their running style and comfort needs. Barefoot running or minimalistic footwear is not some magical solution that every runner needs to adopt. Finally, it is important to understand the differences between running in shoes vs. running barefoot in order to decipher company marketing claims and to understand if there is any utility to planning in small bouts of running barefoot. However, research is still yet to indicate whether there is any real benefit to purposely running in minimalistic footwear or running in no shoes at all for small bouts.
I realize that the topic of running biomechanics and running footwear is a massive one to dissect. My goal in this brief write-up was not to dissect every aspect of this topic, but rather to give you as the reader a brief insight into some of the most recent research literature on some common and often misunderstood topic areas within the space of running biomechanics and footwear. I hope the information provided herein proves to be useful for you.
Cochrum RG, Connors RT, Coons JM, Fuller DK, Morgan DW, Caputo JL. Comparison of running economy values while wearing no shoes, minimal shoes, and normal running shoes. Journal of Strength and Conditioning Research. 2017 Mar 1;31(3):595-601.
Divert C, Mornieux G, Freychat P, Baly L, Mayer F, Belli A. Barefoot-shod running differences: shoe or mass effect?. International journal of sports medicine. 2008 Jun;29(06):512-8.
Jaén-Carrillo D, Roche-Seruendo LE, Molina-Molina A, Cardiel-Sánchez S, Cartón-Llorente A, García-Pinillos F. Influence of the Shod Condition on Running Power Output: An Analysis in Recreationally Active Endurance Runners. Sensors. 2022 Jun 26;22(13):4828.
Lieberman DE, Venkadesan M, Werbel WA, Daoud AI, D’andrea S, Davis IS, Mang’Eni RO, Pitsiladis Y. Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature. 2010 Jan;463(7280):531-5.
Lussiana T, Hébert-Losier K, Mourot L. Effect of minimal shoes and slope on vertical and leg stiffness during running. Journal of Sport and Health Science. 2015 Jun 1;4(2):195-202.
van Oeveren, B. T., de Ruiter, C. J., Beek, P. J., & van Dieën, J. H. (2021). The biomechanics of running and running styles: a synthesis. Sports Biomechanics, 1-39.
Happy training and racing!
-Ryan Eckert, MS, CSCS
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