“Go barefoot, it will make your feet stronger!” Do we have proof of that? Nope. We just assume that shoes make our feet weaker. Recently, researchers at the University of Queensland tested this hypothesis. Lo and behold, they found that EMG activity in some foot intrinsics increased in shod vs barefoot running!
Through intramuscular EMG, the group found that some muscles in the arch of the foot (flexor digitorum brevis, for example) demonstrated both higher peak and longer duration of EMG activity in the test with shoes ON. The group has hypothesized that the foot is attempting to adapt to the unstable surface (the shoe) by making the ankle/foot complex stiffer.
Ankle stiffness is required to bound over the ground when running, so it looks like the “shoes” have it!
Wendy Winn , PT, OCS Director
-J R Soc Interface. 2016 Jun;13 (119). Shoes alter the spring-like function of the human foot during running. Kelly et al.