Placebo-controlled running shoes? It seems like an odd idea, but that’s the approach researchers at the Luxembourg Institute of Health’s Sports Medicine Research Laboratory have taken to test the injury-prevention prowess of various shoe features. Working with the French sporting goods giant Decathlon, they give their subjects shoes that are superficially identical, differing only in one subtle aspect. For example, their most recent study, published in the American Journal of Sports Medicine, varied the height difference between the heel and toe, with a heel elevated by zero, six or 10 mm. After six months, about a quarter of the 553 runners in the study had suffered an injury – but despite claims that “zero-drop” shoes might reduce injury risk, there were no clear differences between the shoe groups.
Previous studies from the same group, led by researcher Laurent Malisoux, investigated the effect of midsole stiffness, which also didn’t seem to matter, and motion control, which did. In the latter study, published last year in the British Journal of Sports Medicine, runners who were diagnosed with a “pronated” foot on a scale called the Foot Posture Index were 66 per cent less likely to get injured if they received the version of the shoe with motion control features – in this case, a piece of rigid plastic and a dualdensity midsole to restrict the inward roll of the foot. Malisoux has more studies planned, with the goal of bringing impartial evidence to a field plagued in recent years by seemingly endless debates. For now, though, his primary advice to shoe-buyers is simple: whatever shoe you choose, make sure it fits and feels comfortable, since your intuition may reflect the way your foot prefers to move.