Influence of Running Shoe Drop on Injury Risk
In our previous posts on running shoes we have described the limitations of orthotics and shoe wear to alter foot, ankle, or knee mechanics during gait. Despite the hype and claims shoes have been unable to significantly improve running mechanics compared to proximal interventions including hip strengthening and gait retraining by a Physical Therapist. The take home message from many large studies is runners have an inherent feel for the right shoe. When allowed to pick their own shoe based on comfort these runners have less injuries compared to runners who were given a shoe based off of their static or dynamic posture during walking or running.
Despite the evidence to the contrary, runners continue to be "prescribed" shoes based on in store testing or recommendations. Unfortunately, the recommendations of shoes often is influenced by the popularity of a given shoe. Recently, we have seen a dramatic rise in the use of minimalist or limited drop shoes. The distance of drop is measured by the loss of height from heel to toe. Thus a zero drop shoe has the same height in cushioning from heel to toe. The zero drop shoe is based off of the idea that minimal shoe wear or even barefoot running may reduce the amount of running injuries seen every year across the country. These shoes are appropriate for some runners but inappropriate for others.
A recent randomized controlled trial in the American Journal of Sports Medicine examined the impact of running shoes of varying drop on injury rate among recreational runners (Malisoux et al. 2016). Over 500 runners were followed for 6 months after being given one of 3 shoes of varying distances of drop including zero drop (0 mm), 6 mm drop, and 10 mm drop. They broke down the injury results by both experience with running and shoe drop height. Overall, the authors found injury risk was not modified by the drop of standardized running shoes. They did mention a caveat that low drop shoes could be associated with more injuries in the recreational runner but may reduce injuries in the occasional runner.
In our experience, zero to low drop shoes can lead to injuries in runners not accustomed to using a shoe with less cushioning or drop. Runners considering a switch to zero drop or low drop shoe are advised to work with a local Physical Therapist to improve their running performance and reduce their injury risk.