Barefoot running, or the use of minimalist running shoes, is a relatively new style of running that has evoked a lot of discussions, both negative and positive. A good discussion about minimalist, a.k.a. zero-drop running shoes, is linked to here in our archives. The supporters of this movement claim that it promotes a healthier running style which will allow injury avoidance. They point to our human ancestors who obviously were barefoot runners. Their argument is that traditional running shoes alter the running posture in an unhealthy way as compared to the minimalist shoes.
Opponents of minimalist running state that the lack of protection and support that these shoes provide are quite unhealthy and simply lead to a different set of injuries. Their stance is that shoes were created to protect the feet from injury, and runners especially benefit from the support and cushioning of traditional running shoes.
Until recently there wasn’t much evidence to validate either one of these positions. But in 2013 a radiologist in Utah (Dr. Douglas Brown) became aware of a lot of barefoot running injuries with the heel and foot, and he commissioned a study in conjunction with an exercise science professor at Brigham Young University. Dr. Sarah Ridge does sports injury studies at BYU and she agreed to take a look at the minimalist running issue. The results of the study are quite interesting.
Dr. Ridge recruited 36 experienced runners to take part in the study. This included both men and women who normally ran between 15 to 30 miles weekly with traditional running shoes. Baseline MRI scans were performed on the feet and lower legs of all the runners, and each were declared to be healthy. Half of the group were then assigned to start incorporating minimalist running shoes into their routines, while the other half were to keep their normal running schedules with traditional shoes. The minimalist shoes used in the study were the Vibram Five Fingers brand.
The Vibram group were told to gradually start using the minimalist shoe by running one mile in them the first week, two miles the second week, three miles in the third week, and as much as they desired after that. (This was the recommendation from Vibram). The study went on for a total of ten weeks. At the end of the study, follow-up MRI scans were performed on all of the runners in both groups.
The results showed no major injuries in the legs and feet of any of the runners. However, over half of the Vibram group were showing signs of early bone injuries in their feet. Dr. Brown observed this by looking at the amount of bone marrow edema present in the feet. This is an accumulation of fluid similar to bruising in the foot bones. The edema is graded on a scale from 0 to 4, with 0 indicating no edema present. A level of 1 is typical for most people, and higher levels can indicate bone injuries.
Most of the group using traditional shoes had normal edema levels of 1 in their feet. But in the Vibram group, the majority of runners had levels of 2 or more. Three of these runners had a level 3 edema which is considered an actual bone injury. Two others had full stress fractures, which quantifies to an edema level of 4. One of these stress fractures was in the metatarsal bone, and one was in a heel bone.
Additionally, nearly all of the Vibram group were running less than expected in the minimalist shoe by the end of the study, likely due to the increasing foot pains. Dr. Ridge was unable to ascertain why some runners had problems with the minimalist shoes but others did not. But is is probably a combination of things such as running style, body weight, foot biomechanics and other physical factors.
Dr. Ridge and Dr. Brown both emphasized that these results cannot be extrapolated to any runner who decides to give the minimalist shoes a try. But the data does point out that the transition period into a minimalist shoe must be approached with extreme caution in order to avoid foot injuries. In fact, a mile per week in the barefoot shoes is likely too much initially. There is a big risk of tendonitis and plantar fasciitis in this period, in addition to stress fractures.
The American Podiatric Medical Association has actually stated that barefoot running improves strength and balance while promoting a more natural running style. But the risk of puncture wounds and increased stress on the feet and legs lead to overall inconclusive results about the benefits of minimalist shoes.
Image courtesy: flickr/Maggie Osterberg