Barefoot vs. Shod Running

In recent years the popularity for barefoot running, 'barefoot' shoes and other minimalist footwear has increased and there are many new companies out there now offering us their version of the barefoot training experience. The main three that people will probably know are Vibram Five Fingers, Vivobarefoot and Inov8.

Initially this was just a very small percentage of the running population, but then i started to notice in 2012 that all the big brands started marketing minimalist shoes aimed at the general running population and not just club runners and elite athletes. You now have;

New balance - Minimus 

Nike - Free 

Adidas - Adipure/Adizero

Brooks - Pure Project

Just to name a few, but all the top brands are now making and selling more of their racing style flats or shoes with lower 4mm & 6mm drops.

When it comes to barefoot running information there are plenty of good sites to check out that have information backed up by research into barefoot running and there's not much point in me trying to match that. I recommend you check out the following links:

Vivibarefoot training clinic - makers of vivobarefoot shoes and researched along side Prof. Lieberman

http://www.vibramfivefingers.com/education/ - Introduction to barefoot training and footcare

So should we be running barefoot?

If you run barefoot on a hard surface you'll notice that it's uncomfortable, almost painful to heel strike. And when asked to run barefoot, most heel runners adopt a forefoot/midfoot strike without being prompted. Surely this means something? Now i'm not saying that everyone can immediately ditch their shoes and run barefoot, because years of adaptation to shoes means that we have de-trained ourselves from this natural movement. But running is a skill, and all skilled movement requires proprioceptive feedback from your extremities to allow your body to adapt to the loads and the environment it experiences while moving. So immediately one argument for barefoot running is that shoes block those signals making it harder to produce skilled running movement.

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Fig: 2 Barefoot & shod heel strike,
Lieberman et al. (2010)

Fig: 3 Barefoot & racing flat forefoot strike,
Lieberman et al. (2010)

Heel strike - barefoot vs. shod

Barefoot running with a heel strike produces similar ground reaction forces however the big difference that shoes make to this running style is delaying the impact transient. Possibly arguing that someone who can only heel run is better off in shoes?

Forefoot strike - barefoot vs. shod

The ground reaction forces are similar, but slightly higher in the barefoot scenario. However the impact transient is the same. It'd be interesting to see the same comparison after a 10km, to give a better insight to sustainability of form between shod and barefoot.

Fig: 4 Forefoot strike in heeled shoe,
Lieberman et al. (2010)

Forefoot strike in heel shoe

When the runner is attempting to forefoot strike in a shoe with a high drop the angle created by they shoe often results in a midfoot strike. The shoe may hit the floor at a flatter angle, but the foot within the shoe is still in the same position as when forefoot striking. In order to get a proper forefoot strike the runner would have to over-point the toes putting additional strain on the calf muscle and Achilles. Despite this the runner in Fig 4 is still able to produce impact graphs similar to than in barefoot and racing flat.

"It's not what you wear, it's how you wear it?"

Possible conclusions to be made from this are that barefoot running may put us back in touch with a skill that many of us have lost. There may also be lots to gain from training & running barefoot to improve how we move in relation to the world around us. But, as the comparison of the forefoot; barefoot, racing flat & heel shoe shows us, as long as you can learn to run properly, you can wear what you like.

Advantages of barefoot running:

• Strengthening of muscles in the foot. Strong muscles will prevent over-pronation and arch collapsing. 
• Biomechanical efficiency in feet and legs can reduce stress on other structures; knees, hips & lower back. From personal experience my lower back felt a lot better on longer runs and in other aspects of my life too.
• Improved running form; increased cadence, energy efficiency
• The feeling of freedom. It feels natural and you can feel your body reacting to the ground. you're aware of slowing down on harder surfaces and speeding up on grass etc.
• Injury prevention? the jury is still out on that one. but i am sold.

So how can you progress to barefoot or minimalist running and what considerations should you take?

• Consult a physiotherapist or barefoot running specialist to get more personalised information and tell them about any injury history. You may find you need to do some strength work first.
• It will take time to adapt to start of slowly with very low volume. I started by resistance training barefoot, then started running as little as 1000 metres a week barefoot on a treadmill and use the 10% rule when increasing volume.
• Look at getting some minimalist shoes. These will protect your from sharp objects and rough ground and provide warmth. look for something with a zero drop or very little build up on the heel. Your choice may also be affected by your budget and your other shoe choice. If you can have multiple sets you can buy the best shoe for each level of your training. But a good all rounder is something like the New Balance minimus range. they provide a thin sole, minimal drop and still feel like a shoe.
• Resistance train to strengthen the running muscles; core, glute max, glute meds, hamstrings and of course calf muscles.
• Use soft tissue release, trigger pointing and massage to help muscle recovery, especially when you're starting a new technique.
• Listen to your body. if you start to feel pain or anything you're not sure of; stop! and get a professional to have a look.

Is there anything wrong with heel striking in shoes? not necessarily. "If it ain't broke don't fix it". sometimes you can do more damage by trying to change someones movement. You should ask what it is you're trying to accomplish, and look at what impact any changes in their movements might have on other areas of their life. If someone has been running injury free for years then i'd be reluctant to change it. However you can still look at posture, cadence and overall form to make sure they are moving efficiently.

I hope this blog had been useful. I want to run better and i want to help others run better too. If you have any questions or comments then i'd love to hear from you. It'd be good to hear from people that have been running barefoot for a while or from anyone who has a different perspective.

Take care.

Thank you to Vivobarefoot education, Vibram five fingers and Lieberman et al. These sites are a great source of information and i really recommend you read these in more detail if you like the subject matter. It's also admirable that these shoe manufacturers are creating such a large amount of freely accessible information about minimalist and barefoot running.

References:
Lieberman et al. (2012) http://barefootrunning.fas.harvard.edu/
Vivibarefoot training clinic (2011) http://trainingclinic.vivobarefoot.com/
Vibram Five Fingers (2012) http://www.vibramfivefingers.it/education_why_barefoot.aspx

Forefoot/Midfoot vs. Heel Striking

Humans are persistence hunting running animals, designed to run at a steady pace over long distances in pursuit of food. From an engineering stand point we are designed to run with a forefoot strike and heel striking or "jogging" is a learned behaviour encouraged by over cushioned shoes that mask the impact forces in running causing us to loose our proprioceptive feedback over time, yet around 75% of runners are heel strikers. Think of it this way; when you're wearing gloves it's really hard to get coins out of your wallet, or find something in a bag. this is because we cannot feel the surface that our fingers are reacting against. Our feet are the 'ears' to our hips and core muscles, what we feel through our feet lets our body know how to react to that surface. Thick soled shoes mask this communication and therefore we no longer run on the ground as we perceive it, but instead by memory. Still not sure? try running 20 metres barefoot at a moderate pace, most people adopt a forefoot strike and find that it is uncomfortable to heel strike.

Foot position on impact

Fig:1. Heel striking vs. forefoot strike

A heel strike causes the leg to impact with a much straighter knee position. Impact causes loading of tibialis anterior while arch remains unloaded. Impact forces are transferred up through the knee.

A forefoot strike places the impact through the multiple bones and ligaments in the foot designed to act like springs. Impact loads the arch to absorb impact. Note also the double-impact graph from heel striking.

In heel striking the heel hits the floor with the full force of impact, however during forefoot striking the heel is lowered to the floor under the control of the posterior calf muscles and Achilles tendon.

Forces on impact 

Lieberman et al. found that heel striking meant that the vertical momentum of the lower leg is absorbed on impact, whereas in a forefoot strike much of the vertical momentum is converted into rotational momentum. Imagine dropping a metal rod on a hard surface upright and the noise it would make because of the force of impact. If you dropped that same rod at an angle it would make less noise because the force of impact is displaced as the rest of the rod rotates to the floor.

Below is the impact transient and total impact forces for a heel striker and forefoot striker (Fig: 1)

Shod heel strike: 0.108 sec impact transient, 2.5 x BW

Shod forefoot strike: 0.124 sec impact transient, 2.49 x BW

The peak impact force for heel striking and forefoot striking are the same however this is the point at which body's centre of mass is lowest the ground, usually when the foot is already underneath the body, but at this point the forces are rising slowly, so it's thought that this is less likely to contribute to injury. However because a larger proportion of the foot and lower leg come to almost a dead stop during a heel strike, compared to a forefoot strike the there is a larger mass under the influence of that ground reaction force. 

The speed at which the force is applied to the body during the impact transient is where we start to see differences. During a heel strike the impact transient is higher than during a forefoot strike, so that force is being applied to the body faster. Because of this there are those that believe that heel striking is a contributor to running injuries. However there are yet to be any direct studies in this area and most evidence is anecdotal. While heel-running shoes do reduce the force by about 10% and spread the force over a greater area, they do not eliminate the impact transient. And as a side note; heel striking causes forced ankle planter-flexion which can lead to overactive tibialis and is linked to shin splints.

Introduction

In recent years there has been an increased interest in running mechanics and improving running form. Magazines are producing more articles about proper running form and injury avoidance. However, when it comes to shoe manufactures, it seems we are still split into two groups; heel strikers and mid-foot/forefoot strikers. So is there a proper way to run and why aren't more big brands putting their foot down (pun intended) and getting behind one or the other type instead of sitting on the fence? Some of the larger companies are now making some great minimalist running footwear, but it's hidden under a plethora of other products, making it difficult for those less informed to choose the right shoe. It suggests that they're still trying to please everyone whether they are running correctly or not instead of going with the research giving us a product that will help us run better. Opinions on what is a correct running technique should form your ethos on how you run a brand and how you design your product. So I wonder how you can put your knowledge and beliefs behind two different forms of running that seem to contradict each other. 

How can a company that believes in this...

... also make this?

Instead, it is left to smaller innovative companies to produce smaller lines of specific running footwear which mean it's usually done at a higher price for example; inov8, Vibram, Vivobarefoot etc. So as you may have guessed I am a forefoot runner and an advocate of minimalist running as a tool for improvement of form, and for some, a way of running.

So how did I get here?

I used to be a heel striker for as long as I remember, and typically wore a neutral Asics which I used to find very comfortable. I experimented with forefoot striking before but found it very tough on my calf muscles and initially gave up and returned to heel striking thinking "it's not for me". I've been plagued with injury and  recently had to have surgery to correct a cartilage issue. So early in the spring of 2012 I attended a barefoot running conference to learn more about this new craze that has people walking around in odd looking finger shoes. I used Vibrams for my resistance training sessions and running drills and very short runs of about 1km at first. On longer runs I looked at reducing my ground reaction forces and vertical travel by increasing my cadence and increasing my heel lift during the recovery phase. After a few months I switched to running in a lighter shoe with a smaller heel drop, the Mizuno wave musha (the gold racing shoe pictured above). I really like this shoe, it's light and has a very small heel:toe drop, which allowed me to start running with a forefoot/midfoot strike but also give the the option of dropping to my heels when my technique fatigued. After about 8 months I was at a stage where I felt like a natural forefoot runner; faster, lighter and if I tried to drop back into heel running it felt odd. I could even run 8km outside on tarmac in Vibrams.