Open Access Open Badges Research article

Uphill treadmill running does not induce histopathological changes in the rat Achilles tendon

Rachel C Dirks12, Jeffrey S Richard13, Angela M Fearon45, Alexander Scott45, Lauren G Koch6, Steven L Britton6 and Stuart J Warden123*

Author Affiliations

1 Center for Translational Musculoskeletal Research, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN, USA

2 Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA

3 Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University, 1140 W. Michigan St., CF-326, Indianapolis, IN, 46202, USA

4 Centre for Hip Health and Mobility, Vancouver Coastal Health and Research Institute, Vancouver, BC, Canada

5 Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada

6 Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA

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BMC Musculoskeletal Disorders 2013, 14:90  doi:10.1186/1471-2474-14-90

Published: 11 March 2013



The purpose of this study was to investigate whether uphill treadmill running in rats created histopathological changes within the Achilles tendon consistent with Achilles tendinosis in humans.


Twenty-six mature rats selectively bred for high-capacity running were divided into run and cage control groups. Run group rats ran on a treadmill at a 15° incline for a maximum duration of 1 hr/d, 5 d/wk for 9 weeks at increasing speeds, while rats in the cage control group maintained normal cage activity. After 9 weeks, Achilles tendons were harvested for histological processing and semi-quantitative histopathological analysis.


There were no significant group differences within each of the individual histopathological categories assessed (all p ≥ 0.16) or for total histopathological score (p = 0.14).


Uphill treadmill running in rats selectively bred for high-capacity running did not generate Achilles tendon changes consistent with the histopathological presentation of Achilles tendinosis in humans.

Animal model; Tendinitis; Tendinopathy; Tendinosis; Overuse