The Effects of a Transition to Minimalist Shoe Running on Intrinsic Foot Muscle Size

Int J Sports Med. 2016 Feb;37(2):154-8. doi: 10.1055/s-0035-1559685. Epub 2015 Oct 28.


A proposed benefit of minimalist shoe running is an increase in intrinsic foot muscle strength. This study examined change in intrinsic foot muscle size in runners transitioning to Vibram FiveFingers™ minimalist shoes compared to a control group running in traditional running shoes. We compare pre-transition size between runners who developed bone marrow edema to those who did not. 37 runners were randomly assigned to the Vibram FiveFingers™ group (n=18) or control group (n=19). Runners' bone marrow edema and intrinsic foot muscle size were measured at baseline and after 10 weeks. Total running volume was maintained by all runners. A significant increase in abductor hallucis cross-sectional area of 10.6% occurred in the Vibram FiveFingers™ group compared to the control group (p=0.01). There was no significant change in any of the other muscles examined (p>0.05). 8 of the Vibram FiveFingers™ runners, and 1 control runner developed bone marrow edema. Those who developed bone marrow edema, primarily women, had significantly smaller size in all assessed muscles (p≤0.05). Size of intrinsic foot muscles appears to be important in safely transitioning to minimalist shoe running. Perhaps intrinsic foot muscle strengthening may benefit runners wanting to transition to minimalist shoes.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Body Height
  • Body Weight
  • Bone Marrow / pathology
  • Edema / diagnosis
  • Edema / etiology
  • Equipment Design
  • Female
  • Foot / physiology*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Muscle Strength / physiology*
  • Muscle, Skeletal / anatomy & histology*
  • Muscle, Skeletal / diagnostic imaging
  • Muscle, Skeletal / physiology
  • Running / injuries
  • Running / physiology*
  • Sex Factors
  • Shoes*
  • Ultrasonography
  • Young Adult