Let me start with a little background: back in the day I was a tank driver, and managed to injure my knees pretty seriously along the way. A couple of surgeries later and many, many, many hours of physiotherapy later, my orthopedist told me that I probably would never be able to run again. Back then, I was fine with it, since I hated running.
A few years later I moved to England and joined the local outdoor/climbing/running community as part of my career. During that time I got introduced to the idea of barefoot running - it was very popular and cool - so I tried it, and loved it. I read Born To Run, like everyone else, and got into running more seriously including long hikes in minimalist shoes and even tried the Vibram FiveFingers. Yes, my wife found it a bit odd too.
I have been using zero drop footwear for over a decade now, and I have no knee pain anymore. I run regularly, hike often, have thru-hiked hundreds of miles, and am an active parent to two small humans. My knees never hurt from these activities, in direct contrast to the prognosis I was given all those many years ago.
So why am I telling you all this? Not to get you into the barefoot running idea. It has turned out to be mainly a fad of the last decade, though some of us stayed with it. No, the reason I'm telling you all this is about what stayed: zero drop footwear, the meeting between traditional movement style and modern footwear technology.
A brief history of modern running footwear
In the olden days, before Nike, you had dress shoes, heels and for the athletes: flats. All runners for a very long time used flat running shoes (aka: flats) for track racing, while the rest of the developing world used what ever they could find to cover their feet and protect them from being shredded.
Fast forward to 1966, Bill Bowerman, Nike and Jogging. Americans were introduced to a new concept: running for physical exercise. Until the 60's, running was only required as cross training for athletes. It became increasingly clear that the modern, sanitary, and increasingly suburban USA needed to move; jogging was the answer.
In 1966, Blue Ribbon Sports (later Nike) developed jogging shoes and found that runners needed support to run on roads in the suburbs. To make the shoes even better, a "bouncing" effect was introduced that included increasing the heel height to "push" the runner forward.
This move to footwear that is meant to move us forward was the end of flats for runners and the introduction of differential and stacked height technologies in athletic shoes.
Differential and Stacked Height
Two terms often used for athletic footwear (including trail shoes) are stacked height and deferential.
Stacked height is the total of height of material between the ground and the foot. This is where the term barefoot, minimal, maximal or other is used. Stack height is marked by mm and are in the specifications part of the shoe (heel, mid, toe). The higher the number, the softer, or more supple, the shoe is.
Differential is the height difference between the forefoot's rest place in the shoe and the heel's, also measured in mm and this is where we find zero drop, aka: zero differential. Here, the higher the number, the higher the heel is compared to the forefoot.
Zero drop footwear
Now that we have defined some terms, we can focus on zero drop footwear: shoes (and boots and sandals) that have a flat bottom and may include lots of cushioning, or none at all.
The idea behind zero drop footwear is to allow a natural stride and gait, utilizing the foot's natural bounce and structure. The foot is like a spring, using the arch to absorb the impact of movement by tensing the calf to avoid hard impact of the heel. By using a flat surface (flat shoe) instead of shoes with an elevated heel, we use that natural bounce and shock absorbing that our feet have instead of a big soft foamy heel in the shoe.
This natural stride and form is now seen as healthier and reduces injury risks for athletes (runners or long distance hikers), especially those engaging in repetitive activity.
There are several companies out there that offer zero drop footwear. Some claim to have "invented" the modern zero drop shoe, but as discussed above, it is a pretty old concept. All sport footwear companies that cater to runners have had a running flat (or race shoe) in their range.
Currently, there are several companies that are carrying the zero drop flag:
- Altra Running
- Xero Shoes
- Vivo Barefoot
- Lems Footwear
Issues with zero drop
After years of getting used to using footwear with some amount of differential (check your shoes, you'll find almost all of them have a heel) people develop short calf muscles, which then causes problems when exploring the world of zero drop shoes.
Natural stride requires shifting our posture forward, utilizing the forefoot (not the the heel) as we stride. This kind of natural movement puts lots of pressure on the calf to rebound the impact from the stride. In order to get the most out of zero drop footwear and a natural stride, especially without injury, there are two key things to do:
- Practice correct form
- Train and stretch calf muscles
Training for healthy use of zero drop footwear
Developing the right form for natural movement is tricky and consists of three factors: standing straight, taking smaller strides and having bouncy steps. Instead of me taking you through a very long attempt to explain, please read this great article from the Natural Running Center: http://naturalrunningcenter.com/natural-running-form/
The article has all you need to run correctly; when you are ready to dive deeply into healthy walking practices that are directly connected to natural movement, research Alexander Technique. For a crash course, the video below explains it all:
The biggest hurdle and the easiest to sort out is caring for calf muscles by strengthening them and elongating them to avoid injury. Tight, sore calves lead to bad form, and increased chance for rolled ankles and shin splits. Caring for your calves should be done by practicing long calf raises, starting gradually and working up to more.
Find a step of choice (can be stairs or side walk) and practice long calf raises:
Aim for doing these twice a day, 3 times each, with increased repetition starting from day 5.
Before getting into any physical activity, check with your doctor to confirm no underlying issue that will prevent you from do this safely.
With the right training of form and calves, you too can enjoy the benefits of zero drop footwear, especially if you are due to tackle a long distance trail. The long term benefits are huge and it does allow for healthier and more comfortable hiking. Just check how many Altra shoes you can find on the long trails in the US to understand how much zero drop is part of being able to hike hundreds of even thousands of miles.
Enjoy your hike!