A recent study seems to indicate that popular minimalist running shoes like Vibram FiveFingers, designed to encourage a barefoot running-style gait, are more likely to lead to bone injury. Now, a physician and natural running advocate says that the research is flawed -- and really just shows that runners need to transition from traditional sneakers to minimalist sneakers more carefully.
Researchers from Brigham Young University wanted to look at how transitioning to Vibram FiveFingers, a popular style of “minimalist” running shoe, affected injury rates in runners. Their work, published in February in the journal Medicine & Science in Sports & Exercise, used a small study involving 36 experienced recreational runners. Seventeen of the subjects ran in traditional running shoes for 10 weeks, while 19 gradually transitioned to Vibram FiveFingers shoes over a 10-week period.
Ten weeks later, MRIs revealed that 10 out of 19 of the runners in the group wearing Vibrams had increases in bone marrow edema -- excess fluid in the bone, which can lead to inflammation. Two of the runners in the Vibrams group suffered foot stress fractures. Meanwhile, just one of the 17 runners in the control group saw an increase in bone marrow edema.
However, Mark Cucuzzella, a professor of family medicine at the West Virginia University School of Medicine who's also a competitive runner and the owner of a store specializing in minimalist shoes, has a few problems with the study.
He points out that seven out of the 36 subjects did not fully document their training, which is a fairly high attrition rate for a small study. But his larger problem was with the transition program used in the study, which he says is out of date.
“In my opinion, no coach or advocate of minimalism would ever suggest a runner completely transition to FiveFingers in 10 weeks if coming out of a traditional shoe,” Cucuzzella said in an email. “For most who have years [of experience running only] in traditional shoes, it takes months, even years, to be able to do the majority of running in FiveFingers.”
The protocol the BYU researchers used dates from January 2011 and was recommended by Vibram at the time. The transition involves starting with short runs in Vibram shoes and gradually adding mileage. But since then, Vibram has updated its transition guide to include more barefoot training exercises that do not involve running, according to Cucuzzella. Vibram's recommended barefoot acclimatization program includes sensory exercises, walking and foot strengthening moves like heel raises, toe grips and toe spreads.
“If you ask a traditional shod runner to go straight into running in minimal footwear, without strengthening the muscles of the foot or addressing form, you are asking for an injury,” Cucuzzella said. “Traditional shoes with support and heel elevation can decondition the foot and promote muscle imbalance. The foot must be retrained and the protocol did nothing to assist foot retraining.”
The study's subjects also did not follow recommendations that they only increase their mileage by no more than 10 percent each week, Cucuzzella points out.
“Wearing Vibrams or any minimalist shoe is not the cause of injury,” Cucuzzella said. “It is the hurried transition out of traditional running shoes.”