• minimalist sandals!

    Xero Shoes - Barefoot Running Sandals

Erik takes his KSO Five Fingers to the Playground

It's a lot easier to do a bit of 'beam' walking in VFFs.
It's a lot easier to do a bit of 'beam' walking in VFFs.
FiveFingers are so amazing that you can levitate in them!
FiveFingers are so amazing that you can levitate in them!
Gotta say: if I was a little kid on a playground looking up at Erik here, I'd be a little scared!  Stranger danger!
Gotta say: if I was a little kid on a playground looking up at Erik here, I'd be a little scared! Stranger danger! Just kidding.
Top of the playground for Erik!
Top of the playground for Erik!
See what I'm saying about levitation?  Erik is flying!  Note the look on the face of his daughter!
See what I'm saying about levitation? Erik is flying! Note the look on the face of his daughter! Superdad!

Above is Erik, having an extraordinarily fun time on the playground in his black Five Finger KSOs. Here's what Erik had to say:


I really enjoy your website and forum, as I've used it from the sizing guide (prior to getting my vffs) and ever since I've received them I've been checking in to see what's new. I figured I'd send some pics because I am enjoying my Vibram KSO's to the point where the use of conventional shoes (at work) has become a chore.

My wife took these pictures at the park near our house in Virginia Beach on an unseasonably warm day last weekend. Since I've gotten my VFF KSO's a month ago, I havent had many chances to use them outside the gym. We took our daughters to play, but I probably had more fun.

Thanks again,

It's a common saying that VFFs make you feel like a kid again — way to prove the point!

Digging into Daniel Lieberman's Barefoot Running Research

A Kenyan elite runner who grew up running barefoot but now runs shod is taped in slow motion running in running shoes.  Screencap from Lieberman research into barefoot running.
A Kenyan elite runner who grew up running barefoot but now runs shod is taped in slow motion running in running shoes. Screencap from Lieberman research into barefoot running.

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!

Results of Daniel Lieberman Barefoot Running Research

Results of Daniel Lieberman Barefoot Running Research
Screencaps from the Nature video, this image shows that initial impact running with a heel-strike registers at around 1.81 x body weight compared to .34 x body weight initial impact running with a forefoot strike. Interestingly, peak bodyweight impact on each curve registers higher with a forefoot strike — around 2.60 x bodyweight running with a forefoot strike compared to 2.30 x body weight with a heel-strike. Note in both running styles here, impact is measured with barefeet.

Daniel Lieberman, Professor of Human Evolutionary Biology at Harvard University, has been conducting a great deal of research into barefoot running. That research has been under peer review for some time now, but is (finally) beginning to see the light of day. What's the verdict? Here's one takeaway: Barefoot running requires a forefoot strike which brings down the impact force to 60% of one's bodyweight.

Before I get ahead of myself, let me kick this off with some video goodness discussing Lieberman's study courtesy of Nature:

There is a lot of press surfacing about Lieberman's research, and I am tracking all of those articles here (see links below). Also, you must take a look at the barefoot running website Lieberman has set up. It covers a great deal of information, from background research, differences between heel strike and forefoot strike running (similar to the graphic above), and even has tips on getting started running barefoot or in minimalist footwear. Check it out.

Now, as for some of the hullabaloo surrounding the research of this ground-breaking research, check out this quote from Nature's initial write-up, A Softer Ride for Barefoot Runners:

Lieberman found that long-distance runners who usually wear shoes, in both the United States and in Kenya, tend to land directly on their heels, abruptly bearing the full force of the impact. The force of the collision, even with a cushioned sole, was the equivalent to up to three times their bodyweight. The force could be linked to common running injuries such as stress fractures and plantar fasciitis, although this has yet to be demonstrated.

Americans and Kenyans accustomed to running barefoot, however, tend to strike the ground with the ball of their feet before touching down the heel — a fore-foot strike — allowing the tendons and muscles in the foot and lower leg to act as shock absorbers, bringing the impact force down to 60% of their bodyweight. The team's research is published in Nature.

"The ankle is a very compliant, springy joint, and barefoot runners use it a lot," says Lieberman. "It isn't available to you when you rear-foot strike. Then you're relying solely on the spring on the heel of the shoe."

The research conducted by Lieberman and also Madhusudhan Venkadesan and Dennis Bramble is described further in a separate Associated Press write-up, Barefoot runners ease into low-impact landings Study shows how humans ran comfortably and safely before the invention of shoes:

Working with populations of runners in the United States and Kenya, Lieberman and his colleagues at Harvard, the University of Glasgow, and Moi University looked at the running gaits of three groups: those who had always run barefoot, those who had always worn shoes, and those who had converted to barefoot running from shod running. The researchers found a striking pattern.

Most shod runners -- more than 75 percent of Americans -- heel-strike, experiencing a very large and sudden collision force about 1,000 times per mile run. People who run barefoot, however, tend to land with a springy step towards the middle or front of the foot.

"Heel-striking is painful when barefoot or in minimal shoes because it causes a large collisional force each time a foot lands on the ground," says co-author Madhusudhan Venkadesan, a postdoctoral researcher in applied mathematics and human evolutionary biology at Harvard. "Barefoot runners point their toes more at landing, avoiding this collision by decreasing the effective mass of the foot that comes to a sudden stop when you land, and by having a more compliant, or springy, leg."

Though none of this may come as a surprise to readers of Birthday Shoes, the importance of Lieberman's work here is that it further calls into question the prevailing paradigm that you must wear heavily cushioned shoes in order to run safely and injury free. Though there are no studies proving that barefoot running results in fewer injuries than shod-running, I have little trouble jumping from "reduced impact from barefoot running" and "how we evolved to run" to "running barefoot is a safer and more injury-free way to run."

It will be fascinating to learn more about Lieberman's research as it emerges from the ivory tower. If I recall correctly, Lieberman's studies also looked at Vibram FiveFingers-shod runners, so it will be informative to see what we learn there, as well.

Below are additional links or material covering the Lieberman barefoot running research release. Sit back, click around, and geek out on barefoot running:

Links to press on the Lieberman Barefoot Running research release:

Here's an NPR's All Things Considered on the study:

H/T to Tuck!

Interview with Patri Friedman, Seasteading Institute Founder

Patri Friedman gets ready for a maiden voyage on a DIY Tensegrity Pyramid / motorized Raft at the inaugural Ephemermisle — check the black Classic Five Fingers and Injinjis
Patri Friedman gets ready for a maiden voyage on a DIY Tensegrity Pyramid / motorized Raft at the inaugural Ephemerisle — an annual floating festival of politics, community and art — check the black Classic Five Fingers and Injinjis (photo credit: Chris Rasch).
Patri walks the plank at Ephemerisle in his Classics.  Note the pirate pajamas! (photo credit: DangerRanger)
Patri "walks the plank" at Ephemerisle in his Classics. Note the pirate pajamas! (photo credit: DangerRanger)

Background: Patri Friedman is perhaps best known as founder of the Seasteading Institute, an organization whose stated mission is "To further the establishment and growth of permanent, autonomous ocean communities, enabling innovation with new political and social systems." In addition to working towards changing our paradigm of governance, Patri is a fan of Vibram FiveFingers. Given the overlaps between VFFs and Seasteading, I asked Patri if he'd answer a few questions about Seasteading for BirthdayShoes.com and he kindly obliged.

Name:Patri Friedman
Birthday:July 29, 1976
VFF shoe size:40
Feet are:fundamental

What originally attracted you to FiveFingers?

I'm a sucker for anything with an evolutionary explanation. Plus, I'm a narcissist and they attract attention. Once I got used to them, I loved the feel and the extra control of getting to use my toes (amazing for stop-and-go traffic, for example).

What VFFs do you own? Do you wear any other minimalist footwear?

VFFs: Black KSOs and Black Classics. Non-VFFs: ASICS Onitsuka Tiger and my current main shoes, Terra Plana Vivo Barefoots.

What have you mostly been doing in your Five Fingers?

Anything, really, from CrossFit to going to a conference. I'm most likely to wear them when I'm appearing in a formal business setting, interestingly enough — but then, I have an unusual business :).

Your current work is focused on the Seasteading Institute, an organization whose goal is to create new frontiers on the open sea by way of manufacturing floating nation-states in the ocean. I can't help but see a tie-in between the Seasteading Institute and VFFs — and I don't mean the fact that Vibrams were originally marketed as boat shoes.

There is definitely a tie-in. I am a contrarian - I like finding ideas which are true but not accepted by the mainstream. But to be a contrarian, you have to be smart, you can't just embrace any fringe idea or you'll be a crackpot. I see barefoot shoes and seasteading as both smart contrarian plays, unusual at first glance but backed by solid science. Wearing my VFFs helps emphasize that I'm calculatedly different.

Both VFFs and floating nation-states have the ability to increase human freedom. What makes seasteading so powerfully freeing?

Both are a return to an environment humans are better suited for. Our bodies were made to operate barefoot, and our minds were made to operate in small tribes. The modern world where we have no personal interaction with our leaders, where we can't build coalitions of our friends to change policies, and where we can't easily leave if we want to start a new tribe, is very different. Seasteading is a return to the world we were designed for, where any small group of people with a passionate vision for a better way of life can pursue it.

VFFs share another common characteristic with seasteads — the idea of a foot glove was (and still is to many) considered fringe and impractical. How do you overcome the resistance you encounter when promoting an unconventional idea like ad hoc nation states at sea?

People usually think it's crazy when they first hear it, but usually it just takes a single 15 to 30 minute talk to change their minds. I'd say there are three basic techniques. First and most important is to get them excited about the outcome, about the innovation we'd get if we had a startup sector for governments. That changes their whole perspective — from coming up with problems to coming up with solutions. Second is to use existing examples, like pointing out that cruise ships are cities at sea, and oil-rigs are permanent ocean installations. And third is to get into the details — let them state their concerns, since we have good answers for all but a few common questions (the true challenges, not the mirages).

You recently held the first Ephemerisle, a self-proclaimed "floating festival of politics, community and art," which took place on a make-shift raft of rafts, boats, and other floating structures. Looks like you wore your FiveFingers for the event. How did they hold up to the task?

They were great for hanging off the sides of boats, jumping around, etc*. Only downside is that my feet got wet, as the VFFs aren't so waterproof.

Check this excellent eight minute glimpse into the 2009 Ephemerisle. Patri is featured therein, and if you're paying attention you might catch his VFFs:

Ephemerisle Documentary by Jason Sussberg from The Seasteading Institute on Vimeo.

Thank you, Patri!

More on the Seasteading Institute and Ephemerisle:

Interested in taking to the oceans as a new frontier for experiments in governance? Check out the Seasteading Institute. Or read about the Seasteading Institute on Wikipedia. Here is the official Ephemerisle website if you want to learn more or participate in 2010.

An article on Ephemerisle by Reason.com. One participant's experience at Ephemerisle. The IrishTimes on the event. Finally, below is a rendering of what a seastead might look like by Andras Gyorf:

* Et cetera includes Patri making good use of his VFFs in a Zorb (see here, here, here, and here)

Topmost photo credit: Chris Rasch

Joe's Five Balls, Five Fingers

Joe's Five Balls, Five Fingers

If you're ever in the mood for juggling 5 mini basketballs, I highly recommend wearing VFF's while doing so. They help keep your balance, and they help your balls stay in the air longer. When gravity is doing everything it can to bring the balls past your five fingers on your hands, the Five Fingers on your feet are doing all they can to not let that happen. Five Fingers seem to be on your side, in the battle against gravity. Juggling becomes a united body experience when wearing Five Fingers, the ground is once again your friend. I like that, because as a juggler, the ground isn't always your best friend. Because, the ground represents drops, and drops represent mistakes. But, without the ground we don't learn. When you respect the ground, you respect gravity. Thanks Five Fingers for reinventing my juggling relationship with the ground. I think we're good now. We're closer at least.

Joe S.

Five balls in the air seems like a lot to manage. Well done, Joe! And thanks for the thoughtful words on gravity, juggling, and reconnecting with the ground.

You might remember Joe from his joggling the Philly marathon in Five Fingers.

Inspired by all this juggling goodness, I asked for a set of juggling balls for Christmas and Santa came through! Still working on it though.

Jawa's Vibram Vacation

Jawa runs on Negril Beach in Jamaica in his Sprint Vibram Five Fingers.  Looks like a beautiful place for a sandy run!
Jawa runs on Negril Beach in Jamaica in his Sprint Vibram Five Fingers. Looks like a beautiful place for a sandy run!

Be sure to check the photos linked below in Jawa's narrative below!

I am sure Vibram Five Fingers have been subjected to various conditions and your website serves as a single, authentic source where real people share their success with Vibram. As you may know I have been using Vibram since September 2009 and recently ran my first half marathon.

This winter break, I decided to go with my Vibram to Jamaica for a two week family vacation. In Jamaica we were very active: I ran on the streets of Montego Bay, climbed Dunn’s Rivera Falls, zipped through the longest (1600 feet long) zipline in Caribbean, jumped from a cliff, swung from a rope over YS falls, ran on the beaches of Negril, snorkeled, scuba dove and much more – all with my Vibram. This was truly a Vibram Vacation.

I wore my brand new taupe-clay sprint for this trip. The first day in Montego Bay, we decided to go to the famous Doctor’s Cave Beach. After snorkeling for about an hour, I was simply floating and relaxing.

Next day we went to the famous Dunn’s River Falls – from where the river merges with the ocean, we trekked upstream about 600 feet (See photo here).

Interestingly they were selling water shoes for $15 and many people asked me where I bought my Gorilla water shoes. We also visited the longest zipline in the Caribbean at Lethe Estate. It has 5 ziplines, varying in length from 250 feet to the amazing 1,600 feet (Here I am flying).

My favorite part of the vacation was in Negril, a small town an hour drive from Montego Bay. Negril claims to have 7-mile long sandy beach. I ran through this beach three times and I can attest it is only 4.5 miles (See photo at the top of the post). In Negril I ran through the Hedonism resort (nude beach), and the best part is that all the eyes were on me (my Vibram) as I ran at a steady, 9 minute/mile pace. I also ran through the main road which was treacherous for about 4 miles. There was no side walk but plenty of broken glasses, pebbles, sharp rocks, discarded furniture, two dead dogs and all kinds of trash. I was still was able to complete a 10+ mile run through the beaches and streets of Negril. Check out my Negril Run Garmin stats.

All my family members are PADI Certified scuba divers and we went for six dives. Of course, I went to dive with Vibram. Since Vibram feels like a glove for the foot, I was able to fit into diving fins (see here) easily. My daughter took this next picture when I was 75-feet under water.

Some additional pictures:

I couldn’t resist doing a headstand in the black river area on the south coast of Jamaica on this beautiful road. This is a single lane road with traffic on both sides so I have to do it quick (see here [getting ready] and here [headstand!])


Dr. Jawa is quite the pioneer for VFFs! Teaching in his black KSOs, racing in his blue camo KSOs, and cooling down with yoga moves in them, too — now he's taken Jamaica by storm!

Incidentally, I too have climbed Dunn's River Falls in my VFFs (Beware my blinding paleness!) — KSOs in my case back in May. They worked like a charm.

As a great number of us are dealing with a frustratingly cold winter, seeing Jawa have such a blast in a more temperate climate induces a mixture of excitement ... and jealousy! I just keep telling myself that Spring is just around the corner!

Thanks Jawa!