By Jordana Bieze Foster
The Achilles tendons of experienced minimalist runners differ from the tendons of those who wear traditional running shoes with regard to size, stiffness, and stress, according to research from the University of Connecticut in Storrs that may have implications for runners transitioning to minimalist shoes.
Investigators used diagnostic ultrasound and isokinetic dynamometry to assess the Achilles tendons of 31 well-trained runners, 17 of whom regularly wore traditional cushioned running shoes and 14 of whom regularly wore minimalist shoes.
Values for cross-sectional area, stiffness, and modulus (a measure of the ability to resist elastic deformation) were greater in the minimalist group than the cushioned-shoe group. Minimalist runners also experienced more stress during contraction of the plantar flexor muscles.
The findings, which were epublished in July by the Journal of Sport Rehabilitation, suggest the Achilles tendon undergoes mechanical adaptations in minimalist runners in response to increased tendon loading, and underscore the need for a gradual transition to minimalist running to avoid Achilles tendon injury.
Histen K, Arntsen J, L’Hereux L, et al. Achilles tendon properties in minimalist and traditionally shod runners. J Sport Rehabil 2016 Jul 21 [Epub ahead of print]