Point-Counterpoint: Minimalist Running Shoes: A Significant Advance Or Injuries Waiting To Happen?
Ridge and colleagues recently conducted one of the best research studies to investigate the question of whether minimalist running shoes do indeed prevent running injuries.3 These researchers studied 36 experienced recreational runners split into two groups: a control group of 17 patients who ran in traditional thicker-soled running shoes and a minimalist shoe group of 19 patients who ran in Vibram FiveFingers minimalist running shoes for 10 weeks. The runners wearing FiveFingers shoes transitioned into these shoes using the same 10-week transition protocol that was published on the Vibram FiveFingers Web site in 2010.
The runners in the study by Ridge and colleagues had magnetic resonance imaging (MRI) scans both before and after the 10-week period to monitor bone marrow edema and any other bone stress-related changes within their feet and ankles.3 Various authors have previously shown that MRI scans are able to detect bone stress injuries of the feet and ankles weeks before radiographs can detect any abnormalities.4-6 Even though pre-training MRI results were not statistically different between the two groups, the post-training MRI scores showed that more runners in the FiveFingers group (10 of 19) showed increases in bone marrow edema after 10 weeks of running than did the control group. In fact, of those who ran in the FiveFingers shoes, one of the runners developed a calcaneal stress fracture while another runner developed a second metatarsal stress fracture. No runners in the traditional running shoe group developed stress fractures during the 10-week training period.
Within the medical literature, there are also reports of runners developing stress fractures and other injuries from running in minimalist running shoes. In a retrospective case series from Salzler and colleagues, 10 runners developed injuries when they switched from traditional running shoes to minimalist shoes.7 These injuries included eight metatarsal stress fractures, one calcaneal stress fracture and one plantar fascia rupture.
In 2011, Giuliani and coworkers also reported two cases of second metatarsal stress fractures in experienced runners when they started running in Vibram FiveFingers shoes.8
The increase in injuries that occurs with minimalist running shoes is possibly due to the more anterior foot strike, greater ankle plantarflexion moment in early stance, greater eccentric plantarflexion muscle involvement and greater impact peak loading rate found in people who run in minimalist shoes. Paquette and colleagues showed this in a recent study that compared the biomechanics of minimalist shoe running to traditional shoe running.9
Questioning The Claims Of A Minimalist Shoe Company
Possibly because these types of running injuries do occur, minimalist running shoe company Vibram now faces accusations, in two class-action suits, of falsely advertising the health benefit claims of their shoes.10,11 Vibram advertised that its FiveFingers minimalist shoes did the following:
• strengthen muscles in the feet and lower legs;
• improve range of motion in ankles, feet and toes;
• stimulate neural function, improving balance and agility; and
• align the spine and improve posture.
To date, there is no scientific research that supports any of the advertised health claims of Vibram. In addition, possibly because of the difficulty people have transitioning to running in the FiveFingers running shoe, Vibram offers a 13-page “step-by-step guide” to shoe owners on how to run in their FiveFingers shoes without getting injured.12 No other shoe company in history has needed to provide its customers with such an extensive manual to prevent them from getting injured.
“Minimalist running shoes” are neither a new idea nor a significant advance forward for runners since thin-soled, lightweight, low heel height differential running shoes have been continuously available as racing flats for years. In addition, a review of the available medical literature reveals no data that supports the notion that minimalist running shoes prevent injuries. Rather, the available research seems to support the fact that minimalist running shoes may lead to increased injury rates in runners.