Digging into Daniel Lieberman’s Barefoot Running Research

Do modern running shoes effectively force runners to heel strike? Here we dig into Daniel Lieberman’s barefoot running research, and also poll the Vibram Five Fingers community regarding how to walk or run in shoes versus Vibrams.

Updated with poll results below!

As I try to keep up with all the buzz on the release of Daniel Lieberman’s much-anticipated barefoot running research, I’m spending more time on Lieberman’s Harvard old-school-styled website titled Running Barefoot or in Minimal Footwear, which for sake of reference, I’ll refer to as “Running BoMF.”

One of the things I noticed on Running BoMF that I’d like to dig into is Lieberman’s speculation as to why approximately 75% of shod runners heel strike. Per Running BoMF’s section Foot Strikes & Running Shoes:

  1. It's comfortable. The shock-absorbing features cushion the force of impact. The graph below compares the forces that occur at the ground for a runner landing on the heel when barefoot (a) and in a running shoe (b). Note the initial impact transient, a nearly instantaneous and large increase in force that occurs as the heel comes to a sudden stop upon impacting the ground. The shoe reduces the force by about 10% and slows the rate of loading considerably. This, in addition to distributing the impact force over a larger area of the rearfoot, makes it comfortable to heel strike.
  2. Thicker rearfoot cushioning than forefoot cushioning. This high heel makes it easier to heel strike because the sole below the heel is typically about twice as thick as the sole below the forefoot. So if your foot would tend to land flat when barefoot, it will land on the heel when in a shoe.
    Barefoot Heel Strike Ground Reaction Force Shod Heel Strike Ground Reaction Force
  3. It's stable. The shoe is designed to prevent too much movement such as pronation. This helps to make runners feel stable in modern shoes.

The thing that jumps off the page to me here is #2, “[If] your foot would tend to land flat when barefoot, it will land on the heel when in a shoe.”

As I’ve moved away from both shod-running and shod-walking, I’ve observed substantial changes in how I strike the ground: in both instances, I’ve shifted towards using a forefoot strike. Striking with the forefoot has become secondhand now.

However, when I have to don shoes with a heel — and it doesn’t take much heel to cause this — I find myself inescapably heel-striking. What gives? Well, my conclusion is the same as Lieberman’s speculation: it’s the elevated heels catching the ground when my foot reaches a near-flat clearance point.

Not that Lieberman was specifying any chronology here, but anyone who has ever watched young children or toddlers walk will tell you they walk on their forefoot — even in shoes (Granted, many of their shoes are moccasins without elevated heels like these). I contend that in a natural state, human beings would naturally learn to walk with a mid-foot or forefoot strike—just like little kids.

It’s just that most shoes make a natural gait impossible*

Given that thicker heeled shoes can force a heel-strike, Lieberman’s other speculations as to why shod runners heel strike naturally follow.

For one, given a cushioned heel that is getting in the way of a forefoot strike, you either fight the design of your shoe, requiring a sharper angle of approach at the forefoot so as to give the heel enough clearance to miss, or you just let the catch do it’s thing and do your best to stay comfortable. I further speculat that even if you can manage a forefoot strike in a thick-heeled shoe, you’re still going to lose some of the biomechanical efficiency that you get with a flat-shoe or barefoot because your foot won’t be able to compress as far to the earth before ramming into the cushion of the shoe (And maybe this is why so many shoes try to capture that reduced compressibility via springs in the heels).

As for the third reason, this seems a natural extension given conditions #2 and #1: running shoes are designed to control your landing. With a monster spike in impact you get when running with a heel-strike, controlling that shock wave would be an important component in design as it’s reverberation up your leg and foot could cause instability.

Anyway, I’m curious if anyone else has noticed that they forefoot strike while running or walking in VFFs or barefoot, but inadvertantly heel-strike in less minimalist footwear, and in particular as with shoes with elevated heels.

It’s gotta be the shoes.
Update with poll results:

Below are the results of a poll that ran from January 28 through February 5 of approximately 100 minimalist footwear wearers. The results provide striking, albeit anecdotal, evidence that shoes with thick heels seem to force a heel-strike.

If you walk/run with a forefoot strike (barefoot or in VFFs), have you noticed that when wearing thick-heeled shoes they catch the ground, effectively forcing a heel-strike?

  • Yes: 94% (95)
  • No: 5% (5)
  • N/A. I don’t forefoot strike.: 1% (1)

Total Votes : 101

Additional notes:

These two videos (barefoot and shod) showing an elite Kenyan runner in slow motion running in running shoes and then barefoot are used to illustrate how the angle of approach is the same in both instances, but in the shod-running video, the heel catches the earth, forcing a heel-strike. Lieberman uses this as an example to bolster his why-heel-strike-when-shod speculation on this page of his website.

Also, see Peter’s video analysis of how individuals run shod or in VFFs here. I made similar comments on that post.

* Link is to a nine page read on the subject — I may go into more detail on this article at a later date as it is fascinating to me!

By Justin

Justin Owings is a deadlifting dad of three, working from Atlanta. When he's not chasing his three kids around, you'll find him trying to understand systems, risk, and human behavior.

17 replies on “Digging into Daniel Lieberman’s Barefoot Running Research”

So very true. The barefoot when parallel to the ground naturally lands on the forefoot given the fact that the foot lands under the body. When a wedge of EVA is added to the heel it is impossible to land on anything but. The only possible way would be to land on your tip toes.

Regarding your question: “Anyway, I’m curious if anyone else has noticed that they forefoot strike while running or walking in VFFs or barefoot, but inadvertently heel-strike in less minimalist footwear, and in particular as with shoes with elevated heels.”

As I have been trying to relearn how to walk in VFF’s, I have been experimenting with forefoot, midfoot, and heel-roll walking styles. The one thing that has been consistent, is that when trying to softly heel roll walk for a period of time, it aggravates my slight case of patello-femoral pain in my knee.

It’s nothing crazy, but it develops a slight ache after a while. I don’t get this when I forefoot/midfoot walk.

However, heel roll walking seems much less awkward feeling or looking. That could be from decades of familiarity with it though.


I tried heel-roll walking for awhile and it didn’t feel good on hard surfaces. I was doing a lot of walking around on concrete (hunting for nursery products at the time) and I had to adjust my gait or face foot pain.

It took me awhile to acclimate to forefoot/midfoot walking, but it finally just clicked. I definitely felt awkward doing it at first, too! It’ll get there in time.

I try to stay away from traditional shoes as much as possible now. I have noticed that even my walking has shifted towards more of a forefoot landing. I’ve found that walking or running in place is a great way to get a feel of how my foot wants to come down on the ground naturally. I think Owen McCall’s sister calls it “stomping grapes”

Speaking of kids learning to walk, if they are going to wear shoes, Robeez or something comparable are great.

“Anyway, I’m curious if anyone else has noticed that they forefoot strike while running or walking in VFFs or barefoot, but inadvertently heel-strike in less minimalist footwear, and in particular as with shoes with elevated heels.”

When I ran track, I noticed that our coach kept telling us not to let the heel strike first, but our shoes forced that behavior unless you were sprinting. It is possible to land on your toes with traditional running shoes, but it takes a lot of fighting against the shoe. Might explain why I preferred to practice in track flats.

“Anyway, I’m curious if anyone else has noticed that they forefoot strike while running or walking in VFFs or barefoot, but inadvertantly heel-strike in less minimalist footwear, and in particular as with shoes with elevated heels.”

Oh yeah. In fact, after running for a month or so in Vibrams this summer, I decided to take my old sneakers out for a spin. It was horrible. With every step the darn heel would get in the way: it was impossible to run cleanly.

That was the last time I’ve run in (or worn) sneakers with a heel.

I was on an eliptical at the gym the other day which is behind all the treadmills. I found it very interesting that all the runners were wearing traditional running shoes and all had a very prominate, observable heel strike. My FiveFingers felt really good right about then.

Absolutely. Its terribly evident in all of my traditional shoes. The outside rear of the soles get worn down, and really rather quickly. You can see it when the shoes sit on the floor, it looks like someone took a knife and shaved the heels off. Its nothing more than common sense. I think.

In 2003 and 2004 I attempted a comeback in running. The local running store recommended the Mizuno Wave Alchemy shoes. I experimented a lot with form. I followed Jeff Galloway’s advice running “tall” and avoiding the “seated” running position. Coincidentally, I found the mid/forefoot strike to be most comfortable and efficient. I felt I could fly (and ended up running a 1:16 half marathon and 2:48 in my first full marathon). I’ve since tried other shoes and was unable to find the same mid/forefoot strike that was so comfortable. I’m attempting another comeback now. A few weeks ago I tried on the Vibram Five Fingers and bought two pairs. I immediately recognized the efficient and comfortable foot strike they allowed and they are a favorite part of my weekly training now.

Anyway, I’m curious if anyone else has noticed that they forefoot strike while running or walking in VFFs or barefoot, but inadvertantly heel-strike in less minimalist footwear, and in particular as with shoes with elevated heels.

Oh, absolutely. Some of it is, I think, force of habit, some of it is the heel, and some is – I believe – the fact that many shoes have a high heel cup in the back, making it easier to flex your feet than to point them.

I’m harder on my heels when walking than running, though – when I run it’s almost always up on the toes, regardless of the shoes. When I’m wearing high heels (which I don’t very often) you have to, or you’ll break your neck.

Shoddy Science
The Nature article is typical of the horrendously poor standard of biomechanical research into running that is exposed in nmy PhD thesis, Initiation and Control of Gait from First Principles.
The first requirement fo accurate reporting of forces, is the drawing of a free-body diagram. The Nature article reports a heel-strike transient force. However, this force is measured at several locations inside sensors buried a few centimeters below ground under a flat steel plate.
There is no direct measurement of the forces at the actual heel in the Nature article.
In my PhD study I measured the forces directly under the heel using a pressure plate. The average forces from 54 subjects and 270 heelstrikes reveal that the phenomenon, blithely referred to as a heel impact transient, does not occur at any biological location in the heel!
The heel impact transient is simply an artifact of the rapid spreading of the forces as the heel squashes onto the ground. Despite the total force peaking, the actual force measurements at the various biological heel localities DECREASE during this period. The net decrease in effect “takes a bite out” of the force curve.

Any shoe that spreads the forces would produce the same artifact.

The so-called science associated with shoe design is very shoddy indeed (excuse the pun 🙂 But excusing the pun does not excuse the pain inflicted by shoddy research.


Does your ‘research’ tell is anything asides from pressure = force/area?

What is your point, except to say that the absolute effect of forces MAY be less than presented? If you communicate your point a little better or apply it to this discussion, that would help. At this time you’re not addressing the discussion in an applicable manner. Thanks.

The research into barefoot walking is available at or the full pdf version from [email protected]

The Lieberman et al’s research that was published in Nature, studies only 16 subjects on an AMTI force plate which has only 4 sensors, each located at least 200mm from the shod heel.

I have by comparison studied 54 barefoot subjects with about 250 sensors, each sensor being located within one millimetre of the anatomical heel.

My thesis contains a mine of detail for those interested in solutions rather than vague opinions.

I was challege by this article. I tried to walk and run. I obsered that when I walked I barely used my heels while in running I used my toes. This article make sense to me because I’m a runner athlets in my school. I can choose a better shoes next time. Thanks for this article.

I am fascinated by all this. I always thought I was rubbish at running – in school, trying to catch a bus etc. Then I realised that I could sprint pretty fast whenever I was on the beach on holiday (not so much in the really soft sand, obviously, but near the sea). I started to noitce how I was running on the beach – more forward propulsion, almost without my heel ever touching the ground and I tried to mimic it at other times. – I do have one pair of shoes I can run in – they are my coco-rose shoes (designed to wear when your feet get tired out partying) and they do indeed have no heel. I am now thinking of buying some vibram five fingers having tried on a pair my friend has – unbelievable. Hoping this might help my back problems too!

Love my five fingers but had an Achilles problem after running stairs. Definitely indexed pain and swelling which has taken about two months to repair. The extreme flexing while running on stairs and the placement of the back of the shoe right over my Achilles was the culprit. Anyone else experience this? I will try another style to see if it hits lower on my heel. Disappointing. Great for yoga though (after the soreness was gone from trauma).

Somehow even with my bulky old shoes I always ran with a forefoot strike. I have no idea how but heel striking is something I have never done at least in my memory

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