Minimalist running shoes revisited
Are barefoot-style/minimalist running shoes effective and safe? There's new research on minimalist running shoes (MRS) and their impact on lower leg and foot injury. If you're a devotee, read on.
Barefoot-style, or minimalist, running shoes are still growing in popularity in the military, and the debate continues over whether this style of running prevents injuries or just causes different injuries. There is new research on minimalist running shoes (MRS) and their impact on lower leg and foot injury. After a 10-week study, runners who transitioned to Vibram FiveFinger minimalist running shoes showed signs of injury to their foot bones, while the runners who used traditional running shoes showed none. The types of injuries the MRS runners demonstrated were early signs of inflammation, which may or may not be associated with pain or joint dysfunction. If they are, it might be difficult for the runner to know he/she is actually injured until it is too late and the injury has progressed. More research is needed to determine if other factors (weight, running form/style, mileage, running surface) contribute to injuries associated with barefoot-style running. At least one recent study suggests running style may be a factor. For more in-depth information, read HPRC’s InfoReveal.
A relatively small group of runners practice true barefoot running (that is, without shoes at all). The idea that “less is more” has spread to the wider running community, but for those who are not ready to abandon their running shoes altogether, minimalist running shoes may offer a “close but not quite” alternative. Minimalist footwear or barefoot-style shoes (for basic protection from sharp and hazardous materials) have become increasingly popular among runners, and Warfighters are no exception. The U.S. Army initially banned the use of MRS during physical training (PT) but has since revised its stance to allow certain kinds of MRS to be worn with Improved Physical Fitness Uniforms (IPFU) and during PT. However, MRS with separate toe slots (for example, Vibram FiveFingers) are still not approved for IPFU or during PT.
Based on cultures where barefoot running is the norm, some people think that wearing MRS results in fewer injuries. MRS product manufacturers claim that benefits of these types of shoes include stronger foot and leg muscles; improved ankle, foot, and toe range of motion; improved balance and agility; and better posture. Others argue that running in these types of shoes only changes the types of injuries but doesn’t necessarily reduce the risk for injuries in general.
What We Know
Despite advances in running-shoe technology, injuries among runners still remain high, with about 50% of runners likely be injured within a given year. From research on different running conditions, we know that running with shoes, even minimalist ones, is not the same as running barefoot. Many barefoot runners tend to strike the ground first with the forefoot (front of the foot) or mid-foot (further back on the foot toward the arch), causing the runner to take softer, shorter strides. On the other hand, wearing any kind of running shoe causes a runner to land on the mid-foot to heel first, which produces larger collision forces compared to true barefoot running.
The question remains: Does minimalist running translate to lower injury rates? While advocates for MRS suggest that landing mid-foot (which MRS seems to promote) disperses collision forces and may improve running economy, the truth is that there are no objective scientific studies to show that minimalist-style running or MRS reduce the risk for injuries. One comparison of minimalist to traditional running shoes found no difference in running mechanics between wearers of the two types of shoes. In fact, while other injuries may be lower among barefoot and minimalist runners, they might be at increased risk for forefoot and mid-foot injuries such as stress fractures and plantar fascia injuries. One recent study found that after 10 weeks of running some runners who transitioned to Vibram FiveFingers shoes had increased bone marrow edema—an early indication of inflammation or injury—in at least one bone. Bone marrow edema may not be accompanied by pain and joint dysfunction, so a person may not be aware that an injury is developing.
There is no general consensus as to which type of running shoe yields faster and less-injured runners. We also know that preexisting injuries, an individual’s weight and body composition, and other joint mechanics play a role in running injuries.
Given the ongoing research in this topic area, there are still many questions about the claims that minimalist running shoes improve running form and decrease injury rates. Because various types of MRS continue to grow in popularity and are being used in the civilian and military populations, consumers should be aware that these types of running shoes may involve both risks and benefits. While there is still much debate about these types of shoes, there is general agreement that there should be a gradual transition to running in MRS if a runner has not used them before. At this point the claims that minimalist runners experience fewer injuries are more from personal testimonials, rather than scientific studies.
Debrief (Military Relevance)
True barefoot running and minimalist running affect a runner’s stride, among other things. How this affects the incidence of running injuries is still unknown; there simply aren’t any studies out there to confirm these claims. On the other hand, some studies do suggest that minimalist running poses its own risk for different kinds of injuries, not necessarily fewer. While running mechanics play a role in injury prevention, it is more likely that the individual characteristics of a runner—for example, a runner’s size, previous injuries, training methods, terrain, etc.—will help decide what style of running and shoe are “best.” The idea that the shoe is the main cause of injury is not plausible, and other factors should be considered in the larger context of running injury rates. Clearly, more research is needed in the field of minimalist running related to injury prevention.
For Warfighters, research is also needed to determine the impact of training with minimal footwear considering that they must switch to boots when on duty. For additional reading on this topic, read the Navy and Marine Corps Public Health Center’s (NMCPHC) Summary of Evidence on the efficacy and safety of barefoot-style running shoes.
Injuries Observed in Minimalist Runners Matthew J. Salzler, Eric M. Bluman, Samantha Noonan, Christopher P. Chiodo and Richard J. de Asla. Foot Ankle Int 2012 33: 262
Running in a minimalist and lightweight shoe is not the same as running barefoot: a biomechanical study. Jason Bonacci, Philo U Saunders, Amy Hicks, Timo Rantalainen, Bill (Guglielmo) T Vicenzino, Wayne Spratford Br J Sports Med. 2013 Apr;47(6):387-92
Barefoot Running: Biomechanics and Implications for Running Injuries Altman, Allison R. PhD, Davis, Irene S. PT, PhD.Current Sports Medicine Reports. Issue: Volume 11(5), September/October 2012, p 244–250