title: Uphill treadmill running does not induce histopathological changes in the rat Achilles tendon.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Center for Translational Musculoskeletal Research, School of Health and Rehabilitation Sciences, Indiana University, Indianapolis, IN, USA.
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Dirks
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Richard
authors.forename: Angela M
authors.initials: AM
authors.lastname: Fearon
authors.forename: Alexander
authors.initials: A
authors.lastname: Scott
authors.forename: Lauren G
authors.initials: LG
authors.lastname: Koch
authors.forename: Steven L
authors.initials: SL
authors.lastname: Britton
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Warden
mesh_terms: D000125:Achilles Tendon / Q000473:pathology*; D000818:Animals; D008297:Male; D005082:Physical Exertion; D051381:Rats; D012420:Running; D052256:Tendinopathy / Q000209:etiology* / Q000473:pathology; D013997:Time Factors