In our discussion of footwear so far, we've talked a lot about what shoes to put on your feet. We saw how those in the shoe industry developed the modern day cushioned and supportive running shoe. Although the intention all along has been to reduce running injury, this hasn't been the case. So could the solution to reducing running injuries be the other extreme – no shoes at all?
The barefoot running movement became popularized by Christopher McDougall's book 'Born to Run.' Since then more and more people are asking – is barefoot running right for me? And everyone seems to have a friend who swears by it. Luckily, as barefoot running has become more popular amongst runners, it's also starting to become a popular research topic for scientists.
If you take a look through different articles and research papers you'll find two main types of arguments that support barefoot running.
The first is the anthropological argument. This is the idea that running without shoes is more natural. That throughout our evolutionary history we developed foot musculature that allowed us to run long distances without shoes, and that this was necessary for survival. Proponents of this argument claim that shoes have led to weak and inflexible feet, limited our proprioception and limited our ability to adapt to the ground.
This argument originated from biomechanical studies that looked at the types of forces that affect the body while wearing shoes, and while not wearing shoes. They compared the magnitude and pattern of impact forces when the heel hits the ground first and when the forefoot hits the ground first. Proponents of this argument claim that wearing shoes while running is harmful because it creates two sharp peaks of impact forces with each stride instead of one relativey smooth impact force.
Lets talk about a couple of basic concepts that will help us understand the research on barefoot running.
What's the difference between shod running and barefoot running?
This seems pretty obvious right? In one case you wear shoes, and in the other case you don't wear shoes. But the key defining factor here is not so much about wearing or not, it has more to do with the type of foot strike in each case. People who have always run barefoot tend to land on the ball of their foot when they hit the ground (forefoot strike). People who have always run in shoes tend to land on their heel when they hit the ground. So quite often when studies talk about 'barefoot running' they're actually talking how the foot is landing on the ground.
What changes when you forefoot strike?
When you land on your forefoot (as opposed to on your heel) your body changes the way you absorb the ground reaction forces.In terms of running mechanics you land on the ground with a flatter foot and with the knee more bent. You also see shorter and quicker steps. When this happens the ankle/calf take on more of the work of shock absorption and less load is transmitted up to the knee. The load is also transmitted to the body more gradually at a slower rate. There are also some studies that showed barefoot running is more efficient.
The case for Heel Striking
When it comes to heel striking it has been shown by some studies that to a certain degree, loading the bone is necessary to prevent injury. Furthermore it's been reported that when the body encounters the higher-rate loading during heel strike the muscular and nervous system is able to respond by fine tuning the activation of the muscles.The body can analyze these forces and make adjustments as necessary. However, increased vertical load rates have also been associated with common running injuries.
Is barefoot better?
That's a bit of a contentious issue. There are a lot of people making claims out there, but technically there isn't any proof yet that barefoot running actually reduces injuries. In fact Vibram, the company that makes five finger shoes (these shoes mimic barefoot running), was sued for making unsubstantiated claims that their shoes reduce running injuries. That doesn't mean that there aren't good things about it though.
Here are all the good things associated with a forefoot strike.
1) Decreased stride length
This has been shown to reduce hip and knee loads
2) Reduced hip adduction
Hip adduction is linked to common running injuries such as stress fractures, IT band syndrome and patellofemoral syndrome
3) Better sensory feedback from the foot and ankle
This has been shown to improve stability and could reduce ankle sprains
4) Increased arch muscles
This reduces the appearance of flat feet and could potentially help with plantar faciitis
The question is – do these good characteristics actually translate to less injury?
A study published earlier this year looked prospectively at about 200 runners to see which group, either the barefoot or shod, sustained more injuries over the course of a year. They found that the barefoot group seemed to sustain a different type of injury, but the injury rate was the same! Barefoot runners tended to have more calf and foot injuries, whereas shod runners tended to have more hip and knee injuries.
So there you have it. Although there are lots of people out there saying that barefoot running is better no one can say with good evidence that barefoot running reduces the number of injuries amongst runners. Neither the anthropological or biomechanical arguments seem to be airtight. That being said there do seem to be a lot of good things about barefoot running – and maybe some of them might be good for you. So the next logical question is – should I try barefoot running? That's precisely the question we're going to answer next blog post! Thanks for reading. We're looking forward to discussing some more practical issues regarding barefoot running next post.
Altman, A. R., and I. S. Davis. "Prospective Comparison of Running Injuries between Shod and Barefoot Runners." Br J Sports Med 50.8 (2016): 476-80. Print.
Davis, I. S. "The Re-Emergence of the Minimal Running Shoe." J Orthop Sports Phys Ther 44.10 (2014): 775-84. Print.
Krabak, B. J., et al. "Barefoot Running." PM R 3.12 (2011): 1142-9. Print.
Tam, N., et al. "Barefoot Running: An Evaluation of Current Hypothesis, Future Research and Clinical Applications." Br J Sports Med 48.5 (2014): 349-55. Print.