Running injuries are common and technology in footwear such as cushioning, support, and motion control continue to advance in hope to reduce injury rates. Chapter 8 in the new edition of the clinical sports medicine textbook, titled ‘Clinical aspects of biomechanics and sporting injuries’ includes a section on the clinical assessment of footwear and describes it as a vital component of any lower limb biomechanical assessment.
But should we be using footwear at all? Humans are believed to have run barefoot or with rudimentary footwear for thousands of years before the invention of the modern running shoe. On top of that, despite regular advancements in footwear technology, injury rates have not significantly reduced. In some way, this explains why barefoot running has increased in popularity. With the recent influx of barefoot running websites, open discussion boards and increased attention from the media, there would be few who would not be aware of this latest craze. Shoe manufactures are well aware of this potential threat to their business and now manufacture a range of minimalist running shoes designed to promote a more ‘natural’ running style.
Currently barefoot running claims to have numerous benefits compared to shod running. However, actual scientific research is sparse and has not reached a clear consensus. A recent systematic review, featured in the Journal of the American Podiatric Medical Association, searched the literature for these benefits. A handful of experimental studies and numerous discussion and expert opinion pieces were identified (low levels of evidence). This review summarised the benefits of barefoot running as a reduction in impact forces, improved economy of running, increased proprioception, reduced running injuries, increased lower limb strength and reduced financial cost. Disadvantages of barefoot running reported in the literature included an increased risk of injury from running surfaces and debris, increased exposure to microorganisms and infectious agents (especially in the presence of minor cuts and abrasions) and increased impact forces in previously shod runners.
Doctor Daniel Lieberman, from Harvard University runs a dedicated biology lab investigating the biomechanics of running and compares habitually barefoot runners with shod runners. Lieberman has recently published a review titled ‘What We Can Learn About Running from Barefoot Running: An Evolutionary Medical Perspective’ and summarises current high-quality research surrounding barefoot running. He notes that current research is inconclusive and warns readers to be wary of studies that investigate the effects of what happens when shod runners go barefoot. He clarifies that the perceived benefits of barefoot running are found in those habitual to the process and there are considerable biomechanical differences between habitual barefoot runners and shod runners who have removed their shoes. For example, studies have shown that shod runners typically land with heel or rear foot contact whereas habitual barefoot runners land either on the forefoot or mid-foot. Habitual barefoot runners also take relatively shorter stride lengths; have an increase stride cadence and callus build up on the plantar aspect of the foot. therefore barefoot runners, in theory, are better equipped to take advantage of stored eccentric energy in the Achilles and longitudinal arch and therefore should be able to utilise greater foot and lower limb strength to cope with the ground reaction forces rather than relying on footwear to dampen the loads.
Despite the lack of research evidence there are still some clear and common sense take home messages for clinicians. Most people have adapted to a lifestyle that involves a significant amount of sitting. When they are standing up they are almost exclusively wearing some type of footwear. We must acknowledge and not ignore the significant biomechanical and physiological adaptations that have already occurred within their bodies as a result of this lifestyle. Accordingly, any transition to less supportive footwear should be gradual. Acknowledgement should be made to the differences in running style between individuals and the specific biomechanical adjustments required for each individual.