The Barefoot Running Debate
The debate around barefoot running this time around centred on a paper published in the Journal of Nature by Lieberman 2010 following an observational study on the variation in forces acting through the lower limb with differing foot strike patterns.
Above is an extract from the Lieberman paper. The graph on the left shows the impact forces on the limb when landing on the heel and the right the same force profile when landing on the forefoot. The overall peak force is the same for both condition when you look at the mid portion of the line, the key feature is the initial peak seen in the heel group. The paper suggested that a rearfoot striking pattern resulted in a greater impact force for the limb when compared to the force profile for the same running when landing on the forefoot. This had been reflected in research undertaken back in the early 80’s and at that time these same type of discussions ensued.
The reality with any change in running style is that we are simply changing one group of mechanical forces for another and no one is able to predict that the new group of mechanical forces are not going to create problems. The whole essence of musculoskeletal assessment and biomechanical analysis is around fine tuning and optimising function for that particular set of parameters.
Why Make the change?
There are 2 main reasons why an individual might look to alter their running gait;
Minimise the risk of injury
Improve their performance levels
Minimise the risk of injury
Clinical evidence across Northern European and North American sports medicine units have shown a trend towards different patterns of injury within our running population so a wholesale change in running style does not appear to have minimised the risk of injury, more so its changed the type of injury.
Anecdotally this does not appear to be a major finding on discussion with runners I treat but by default the runners I treat are injured! When we look at their speed work for distances between 2-5Km there appears to be a moderate improvement in running times but this is not transferred into their longer distance work. It seems that runners struggle to maintain their form over greater distances and that there is a threshold distance or volume of running that the body can cope with until it breaks down.
The barefoot running debate without doubt has added value to the discussion around movement analysis and looking at where the foot strikes the ground is an additional layer of biomechanical data collection that in some cases provides a direct avenue for making change. However, the debate in the main has been taken out of context and this panacea approach to minimalist footwear and on the rarer occasions barefoot running has resulted in an increase in foot and ankle conditions such as achilles tendon overload, calf injury and stress reactions in the metatarsals and there appears to be a direct causal relationship.
Lieberman himself a true barefoot runner alluded to the lack of robust evidence in a statement on his website;
"We emphasise, however, that this hypothesis on injury has yet to be tested and that there have been no direct studies on the efficacy of forefoot strike running or barefoot running on injury.
What is the value in a minimalist shoe?
The number of running shoe options available commercially is at best confusing even for experienced clinicians working in and around the running shoe industry. The technologies within running footwear continue to evolve and the investment in R & D for the big players is vast. The investment in material technology perhaps is the most interesting area and the quest to find a material or a combination of materials that reduce shock when the foot hits the ground is a key objective for most companies.
There is an argument that a % of running footwear is overly engineered and on a personal level I would agree with that view. This is a relatively small finding when assessing most running footwear with the biggest issue more to do with material fatigue, all materials have a life span and running in shoes beyond 6 months old for most people who run a moderate distance is an optimum time frame regarding shoe life.
The minimalist footwear will have a significantly reduced ability to absorb impact forces at a foot level whether you land on your heel / midfoot or forefoot and this force has to be absorbed at some level within the musculoskeletal system. Regardless of where you land on your foot a running shoe with a decent midsole material will help in reducing force acting on the musculoskeletal system.
How would you summarise your thoughts around the Barefoot Running Debate?
Lieberman’s work should never have been viewed as advocation of barefoot running. The fundamental point it raised was how ground reaction force behaves in a runner who lands on the heel versus how that same force behaves when a runner lands on the forefoot.
In my running population who have high impact forces and are significantly rearfoot dominant I will look to modify their running style and modify their landing foot position to be more midfoot than heel but not to be on the forefoot as this places an overload onto the calf muscle complex and achilles tendon in addition to the increased burden on the metatarsal bones. This will be for around 10-15% of my running group.
The minimalist footwear movement would appear to have jumped on the barefoot bandwagon and used parts of Lieberman’s work.
An aggressive marketing strategy has encouraged a reasonable number of runners that less is more when it comes to running shoe design. Running in a shoe with appropriate shock absorbent material minimises a significant risk factor when we look at running related injuries and sourcing a shoe that suits your body weight / running style / landing angles and running volume is essential and this has to viewed on an individual basis rather than a mass use of a minimalist shoe that will transform your running world.
In a similar fashion an overly engineered shoe can also create mechanical and functional consequences and these 2 running shoe options represent 2 ends of the spectrum when we look at running shoe options.
Running shoe selection is one facet of the multiple factors that predispose a runner to injury and needs to assessed together with strength and conditioning / structural alignment / joint range of movement / running volume and running recovery. Its a combination of these factors that lead to lower limb injury and running shoe selection is a component part of this, removing footwear or stripping off the protective qualities of the running shoe when running for the majority of runners but not all runners is increasing the risk of developing lower limb injury when we view the evolving clinical evidence.
Pure Sports Medicine
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