and what have we been saying for the last several years?

“The development of bone marrow edema after transitioning from traditional running shoes to minimalist footwear is associated with small intrinsic foot muscle size, according to research from Brigham Young University in Provo, UT.

The findings, epublished in late October by the International Journal of Sports Medicine, suggest that runners with small intrinsic foot muscles may benefit from strengthening exercises prior to attempting the transition to minimalist running.

Investigators randomized 37 habitually shod runners to 10 weeks of running in minimalist footwear or their own shoes, and performed magnetic resonance imaging at baseline and after the intervention to detect bone marrow edema and assess intrinsic foot muscle size.

Eight of the runners in the minimalist group had developed bone marrow edema at 10 weeks, as well as one in the control group. Those who developed bone marrow edema had significantly smaller intrinsic foot muscles than those who did not.

In addition, running in minimalist footwear was associated with a 10.6% increase in abductor hallucis cross-sectional area, a statistically significant change”.

Source:

Johnson AW, Myrer JW, Mitchell UH, et al. The effects of a transition to minimalist shoe running on intrinsic foot muscle size. Int J Sports Med 2015 Oct 28. [Epub ahead of print]