There is a lot of discussion being generated lately regarding the pros and cons of using running shoes to run. It has only been since the 1970’s that we have used running shoes, however, we’ve managed to run since the start of our caveman days. A great new article has been published by Lieberman et al. (2011), looking at running forces with and without shoes…it may help to shed a little light on this area for you.
Background Information: Runners typically are injured at the moment their foot makes contact with the ground. This can happen in three ways: a rear-foot strike (RFS), in which the heel lands first; a mid-foot strike (MFS) where the heel and ball of the foot land at the same time; or a forefoot strike (FFS) where the ball of the foot lands before the heel comes down. Sprinters typically use the forfoot strike but about 75-80% of runners who wear running shoes rear foot strike. Because of this, they need to absorb the vertical ground reaction force (1.5-3x’s body weight). This amount of force very easily breaks down the tissues and can cause injuries in the foot, ankle, lower leg, knee, hip, pelvis,etc..
Running shoes are typically designed to make running comfortable and produce less injures by using materials in the heel to absorb the force.
In the study, forces of ‘foot strike’ were studied amongst Kenyan runners (who ran barefoot), Kenyan runners who initially trained barefoot but now wear shoes, USA athletes who wore shoes and USA athletes who ran barefoot. Interestingly, it was shown that habitually barefoot runners often landed on the forefoot or mid foot. In contrast, habitually “shoed” runners mostly rear-foot strike, as a result of the elevated and cushioned heel of the modern running shoe. The study demonstrated that barefoot runners generated smaller collision forces that shoed rear-foot strikers because the ankle lands in a more ‘compliant’ position and is better able to flex and decrease the mass of the body that collides with the ground at foot strike. In summary, forefoot and mid-foot running patterns are probably our more ‘natural’ running technique but we have evolved the technique into more of a heel strike pattern since the 1970’s and the dawn of the running shoe.
Before I recommend throwing out those running shoes, I strongly recommend taking a local barefoot running class to learn the technique (for example: Challenge By Choice offers these in Squamish). Learning forefoot and mid-foot running technique could be helpful from both a performance stand point and an injury prevention stand point… but like everything, moderation is key. I am NOT endorsing the idea of running a 10km race in your barefeet!! However, experimenting with your technique and with your equipment (shoes or no shoes) is often a very valuable approach to training. Best of luck!
(Lieberman et al. 2011, Foot strike patterns and collision forces in barefoot versus shod runners. Vol 463|28 January 2010| doi:10.1038/nature08723