title: Overweight and obesity alters the cumulative transverse strain in the Achilles tendon immediately following exercise.
abstract: This research evaluated the effect of obesity on the acute cumulative transverse strain of the Achilles tendon in response to exercise. Twenty healthy adult males were categorized into 'low normal-weight' (BMI <23 kg m(-2)) and 'overweight' (BMI >27.5 kg m(-2)) groups based on intermediate cut-off points recommended by the World Health Organization. Longitudinal sonograms of the right Achilles tendon were acquired immediately prior and following weight-bearing ankle exercises. Achilles tendon thickness was measured 20-mm proximal to the calcaneal insertion and transverse tendon strain was calculated as the natural log of the ratio of post- to pre-exercise tendon thickness. The Achilles tendon was thicker in the overweight group both prior to (t18 = -2.91, P = 0.009) and following (t18 = -4.87, P < 0.001) exercise. The acute transverse strain response of the Achilles tendon in the overweight group (-10.7 ± 2.5%), however, was almost half that of the 'low normal-weight' (-19.5 ± 7.4%) group (t18 = -3.56, P = 0.004). These findings suggest that obesity is associated with structural changes in tendon that impairs intra-tendinous fluid movement in response to load and provides new insights into the link between tendon pathology and overweight and obesity.
authors.affiliation: Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland 4229, Australia. swearing@bond.edu.au
authors.forename: Scott C
authors.initials: SC
authors.lastname: Wearing
authors.forename: Sue L
authors.initials: SL
authors.lastname: Hooper
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Grigg
authors.forename: Gregory
authors.initials: G
authors.lastname: Nolan
authors.forename: James E
authors.initials: JE
authors.lastname: Smeathers
mesh_terms: D000125:Achilles Tendon; D000328:Adult; D000843:Ankle Joint; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D012090:Cumulative Trauma Disorders / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000503:physiopathology; D050177:Overweight / Q000503:physiopathology*; D055070:Resistance Training / Q000009:adverse effects*; D013314:Stress, Mechanical; D052256:Tendinopathy / Q000209:etiology / Q000503:physiopathology*; D016474:Weight-Bearing