Terms like barefoot running, forefoot running, midfoot running, chi running, minimalist running, etc. get bandied about so often these days that it’s difficult to define any of them and they’re all starting to lose any true meaning. Here at Newton, we think ‘natural running’ best describes what we’re all about. What do you think? (click image to enlarge)
There’s a great discussion going on over at RunnersWorld.com about a new study that links running shoes to injuries here. Here are a few thoughts that our Director of Education, Ian Adamson, would like to add to the dialogue:
- There are several on-going, multi-year studies at Harvard, MIT and the University of Newcastle (AUS) that are looking at injury related to footwear. Harvard department of Anthropology is about to publish a study that dissects unshod human running gait and injury (or lack thereof.)
- If the only injury from running shoes is Achilles tendinitis, is the implication that the other “running related injuries” such as neuromas, plantar fascitis, blisters, bunions and joint problems would be present in if people didn’t run?
How Shoe Geometry Affects Running Gait
I’m on the front line seeing runners who present with all of the above and more, and the vast majority are treatable with appropriate shoes (the closer a shoe reflects the geometry of the foot the better, although protection from man-made and unnatural surfaces is prudent), especially a lower heel/ramp angle combined with proper form coaching.
There is no doubt in my experience (running competitively since 1973, 12 years as a professional athlete, 10 years in the shoe industry, 10 years as a bio-mechanical engineer) that lifted heels in running shoes introduce an unnatural geometry that interferes with our natural (and injury protective) gait.
Ramp Angle Comparison in Minimalist Shoes
It would take a lot to convince me that strapping 1/2 to 1″ foam to your heel doesn’t alter your stride. If you cut virtually any running shoe lengthwise you can see the drop from heel to the ball of the foot. The Nike Shox as noted above is one of the worst offenders. It used to be that 24 mm heel height (1 inch) and 12 mm (1/2″) forefoot was standard, but those numbers have changed dramatically in the last few years. Some popular running shoes are up to 35 mm in the heel.
The old standard drop (24-12) gives an 8% grade in a Men’s US size 9 shoe, but most are now far in excess of that, up to 15% in some cases. An 8% road grade (rise/ run as a %) is where most states give truckers a warning. Racing flats can be better in terms of being more level, but virtually none are actually level. The best on the market are:
- Vibram (2 mm differential = 1.3%)
- Newton Performance Racer (2 mm/1.3%)
- Newton Performance Trainers (3 mm/2.0%)
- Newton Guidance Trainers (5 mm/3.3 %)
- Asics Piranha 3 (6 mm/4.0%)
- Biom (8 mm/5.3%)
It is interesting to note that some perceived “flat” shoes are not: Nike Free 5.0 (10 mm/6.7%), Nike Zoom Streak XC (11 mm/7.3 %), Nike Luna Racer (12 mm/8.0%), Brooks T6 (13 mm/8.7%). On the other end of the spectrum, the Brooks Beast has a 16 mm drop and 10.7% grade.
My personal experience: ran track and cross country barefoot and injury free through high school. Ran in Dunlop Volley tennis shoes through college (no heel lift http://www.volleys.com.au/flash/index.html), injury free. Was given a “modern” running shoe with a heel lift by a sponsor in 1989 and sustained my first running related injuries. Started back with level shoes again in 2007 (Newton) and viola, injuries gone.
This interesting study published in the November issue of Foot & Ankle International (FAI), the official scientific journal of the American Orthopaedic Foot & Ankle Society (AOFAS), details the biomechanical changes that occur in feet during high heel wear and the correlation between the heel height and amount of pain, pressure and strain it puts on your feet.
The study was conducted on people walking, not running in high heels, but it’s reasonable to assume that the forces involved in running in a 1/2” heel lift are considerably higher than walking.
The study’s authors suggest limiting heel height as well as the use of padding at the ball of the foot can significantly reduce discomfort and risk of injury to the metatarsal heads.
Newton Running Performance Racers have a 2 mm drop from heel to toe, the Performance Trainers are 3 mm and Guidance Trainers (Sir and Lady Isaac) are 5 mm. The typical running shoe has a heel lift of a 1/2 inch or more. You do the math.
At the start of the first American running boom in the 1970s, most people were running in fairly lightweight shoes that consisted of a rubber outsole a thin foam midsole and a lightweight nylon upper. Although simple by today’s standards, some of those early shoes were pretty good at allowing the foot to move naturally without the need for excessive muscular force and allowed a runner to obtain afferent feedback from each foot’s interaction with the ground.
As footwear technology advanced over the years, running shoes generally became cushier, softer, thicker, heavier and, in some respects even more comfortable. But, while some of the innovations were driven by performance, the end result in many cases was anything but performance-oriented. And that’s why, 30 years later, thousands of runners run with inefficient mechanics predicated on a heel-striking gait. Not only is that form not optimal for running fast, it can also lead to numerous overuse injuries.
The biggest culprit of modern running shoe design is that most training shoes have large, overbuilt heel crash pads that encourage and really only allow a heel-striking gait. Even if you wanted to run with a natural midfoot/forefoot stride pattern, the geometry and heel height of many shoes will not allow your foot to land naturally or parallel to the ground because the hefty heel gets in the way.
What is Natural Running?
Simply put, natural running is the way the human body was meant to run in its purest form - namely, barefoot – across a solid surface. That means running with efficient mechanics centered around landing lightly on the midfoot/forefoot (the ball of the foot, but not the toes) and quickly lifting your foot off the ground instead of pushing off with excessive muscular force.
In order to accommodate that style of running, a runner needs to be able to feel the ground and interact with it accordingly just as when barefoot.
And to do that, the runner needs to be wearing lightweight, minimally designed running shoes. The afferent feedback from feeling the ground encourages your body to run with light footsteps, upright posture, a relaxed arm swing and a slight forward lean.
That important feedback is obtainable via minimalist, lightweight running shoes designed to allow the foot to strike the ground with a natural midfoot/forefoot gait but is impossible to receive wearing thickly cushioned shoes and a heavy heel-striking gait. Practicing natural running form can be simple, but it may take time to unlearn old habits and learn proper technique. Ultimately, natural running can help make a runner stronger, more efficient and less prone to overuse injuries.
What Are Minimalist Shoes?
Minimalism in its simplest form involves picking shoes that allow the foot to move more naturally than standard shoes allow. But not all minimal shoes are created equal. Newton Running shoes were designed to be an extension of the feet, enhancing ground contact without the jarring impact shock of the road, sidewalk or hard-packed trail below.
Newton’s reduced heel height and sleek geometry allows the shoe to stay out of the way as it approaches the contact with the ground, and along with enhanced forefoot communication, allows the runner to strike lightly at the midfoot/forefoot instead of using a heel-striking motion that requires heavy breaking and excess muscular force.
Newton Running’s patented Action/Reaction Technology™ encourages natural running or a barefoot running gait and enhances the shock absorbency, leverage and energy return throughout the gait cycle, ultimately helping achieve a faster cadence and more efficient mechanics. Newton’s independent lab research shows the system returns up to 28 percent more energy and reduces impact up to 44 percent when compared to training and racing shoes offered by leading running brands.
Practicing natural running form can be simple, but it may take time to unlearn old habits and learn proper technique. But it also requires having the appropriate footwear to allow your body to run the way it was designed to run. Once you learn to run naturally, you’ll put yourself in position to run faster and healthier for the rest of your life.
Click here for a video about Choosing the Best Shoes for Your Needs.
Danny Abshire is the co-founder of Newton Running, a Boulder, Colo.-based company that makes shoes that promote an efficient midfoot/forefoot running gait. He has been making advanced footwear solutions for runners and triathletes for more than 20 years.
By Danny Abshire, co-founder, Newton Running
Do you think a running shoe with a thickly cushioned heel pad and rigid medial post can keep you from suffering common running injuries such as plantar fasciitis, iliotibial band syndrome or shin splits? Think again.
Recent research and news reports are confirming what those close to the sport have known for years: running shoes with thick midsoles, extensive anti-pronation devices and large heel crash pads don’t prevent injuries.
The key to preventing running injuries is to run with lightweight shoes and efficient, low-impact running form. Running in heavy, overbuilt running shoes can put more strain on a runner’s body, reduce proprioception necessary to engage proper form and make a runner’s feet and lower legs overwork braking and propulsive muscles and connective tissue — a combination which can actually make a runner more prone to common overuse injuries.
A recent study at the University of Newcastle in Australia concluded there is no scientific evidence to support claims that running shoes with elevated heel crash pads and elaborate anti-pronation systems prevent injuries in runners. The findings have been published in the March 2009 edition of the British Journal of Sports Medicine.
“Since the 1980s, distance running shoes with thick, heavily cushioned heels and features to control how much the heel rolls in, have been consistently recommended to runners who want to avoid injury,” Dr. Craig Richards, one of the researchers, said in a press release announcing the results of the study. “We did not identify a single study that has attempted to measure the effect of this shoe type on either injury rates or performance. This means there is no scientific evidence that [those shoes] provide any benefit to distance runners.”
Dutch researchers have previously found that between 37 and 56 percent of recreational runners become injured at least once each year. The most common maladies are found in the feet and lower legs, but others include pelvis and lower back injuries.
“Not only can we no longer recommend a shoe [with an elevated heel and pronation control system], but the lack of research in this area means that we cannot currently make any evidence-based shoe recommendations to runners,” Richards said in the release. “To resolve this uncertainty, running shoes need to be tested like any other medical treatment, in carefully controlled clinical trials.
“This will ensure that only running shoes with proven benefits can be marketed and sold as therapeutic devices. Until this occurs, health professionals will not know whether the distance running shoes they are recommending are beneficial, harmless or harmful.”
A recent story in the London Daily Mail confirmed what the Australian report suggested in an excerpt from a new book called “Born to Run” by journalist Christopher McDougal. That story referenced Dr. Daniel Lieberman, professor of biological anthropology at Harvard University, who offered the startling conclusion that: “A lot of foot and knee injuries currently plaguing us are caused by people running with shoes that actually make our feet weak, cause us to overpronate (ankle rotation) and give us knee problems.”
To run efficiently, you have to understand your body and how it naturally moves across a surface with as little muscular force as possible. The tenants of good running form include running with short strides and a quick cadence, landing lightly on the midfoot/forefoot area (the ball of the foot, but not the toes), and quickly lifting your foot off the ground instead of pushing off with excessive muscle force. A slight forward lean and a relaxed arm swing are also key components.
To illustrate what Newton Running calls the “Land-Lever-Lift” technique, take the simple test of running barefoot across a smooth floor. More than likely, you’re naturally going to land lightly at your midfoot/forefoot and quickly pick up your foot to start a new stride. Your body doesn’t allow you to land on your heels because it isn’t engineered to accommodate the blunt force trauma of repeated heel striking. Unfortunately, most contemporary running shoes have been designed for running form that demands heavy heel striking and dampens the afferent feedback which allows the foot to sense the ground.
Two of the biggest mistakes distance runners can fall prey to are 1) excessive heel striking that causes abrupt braking of forward momentum, and then pushing off too hard with the toes to start the forward motion again; or 2) using only propulsive muscles,(the calf group, hamstrings and Achilles tendon) by running too far up on their toes like a sprinter and not using the body’s natural cushioning system. Each of those form flaws puts too much vertical movement into every stride, and that leads to inefficiency and considerably more impact, muscle and tendon stress on the body.
Danny Abshire is the co-founder of Newton Running, a Boulder, Colo.-based company that makes shoes that promote an efficient midfoot running gait. He has been making advanced footwear solutions for runners and triathletes for more than 20 years.
Although he doesn’t actually test Newton shoes, Adam Weiner from Popular Science offers an interesting take on the science of Newton Running technology in this article, Will Barefoot Running Cure What Ails Us? I love his intro:
“First of all, let’s set the record straight. Man is a natural long distance runner. Despite impressions to the contrary foisted on us daily from our predominantly sedentary and ‘well-fed’ modern lifestyle, it is interesting to note that for long enough distances a well-trained human can outrun just about any other creature on the planet.”
Weiner then further evaluates:
“In fact, consider the following: Man evolved to run barefoot, and shoes arrived on the scene only in the last few tens of thousands of years or so. Try running barefoot some time (preferably on a softer surface like grass) and pay attention to your foot strikes. You might find that it’s almost impossible to land heel first. Your command central (your brain) just won’t let you do it. Too much jarring. Your bare heel isn’t designed to handle that pounding. The evidence supports that landing nearer the middle to front of the foot is the most efficient way to go.”
Check out the full Popular Science story here. We’re going to try and get Mr. Weiner in some Newtons so he can actually try them for himself.
Science and innovation are cornerstones of our business at Newton Running. Over ten years ago, when Newton Running co-founder Danny Abshire first started testing radically different running shoe prototypes, he recognized the importance of a quantitative, scientific results to prove Newton technology designs worked.
However, Danny soon learned that current lab testing is antiquated and frustrating ‘science’ at best. For years now, the standardized running shoe lab test has consisted of a piston that hammers down on the heel of a shoe to test cushioning. There are numerous problems with this testing method, but first and most obviously, it only evaluates the heel – not very useful for Newton shoes, which focus technology in the forefoot of the shoe.
Enter: MIT graduate students.
For their 200 level engineering class, a team of MIT engineering students spent the last semester developing a new running shoe lab test. Here’s the abstract from their presentation:
“Current ASTM tests on running shoes are insufficient because they do not reliably capture the loads and displacements applied to shoes during running. This team will discuss a 3-axis machine that can be used to test running shoes that mimic’s natural running more accurately than conventional tests.
The design is comprised of a phantom foot that replicates the passive properties of a human foot and an actuated base that can impose the relevant kinematics to the running shoe. The shoe is mounted on motor to give a rotational degree of freedom. The shoe and the base are instrumented to measure force and displacement dynamically during the running cycle.
The machine can be calibrated to emulate different types of runners by adjusting the trajectories of the base. As a proof of concept we have collected force, displacement and energy data from the machine.”
Click here to watch a presentation of the innovative testing machine the students designed. We’re thoroughly impressed with the results that the test has yielded so far. The design is patent pending and we’re excited about the possibilities to use a machine like this for our future testing.