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Overweight and Obesity Alters the Cumulative Transverse Strain in the Achilles Tendon Immediately Following Exercise

Scott C. Wearing, PhD,a,b Sue L. Hooper, PhD,b Nicole L. Grigg, PhD,c Gregory Nolan, M.B.B.S., F.R.A.C.S,d James E. Smeathers, PhD c

a

Faculty of Health Sciences and Medicine, Bond University, Queensland, Australia

b

Centre of Excellence for Applied Sport Science Research, Queensland Academy of Sport, Queensland, Australia

c

Institute of Health and Biomedical Innovation, Queensland University of Technology, Queensland, Australia

d

Southport Bariatrics, Pacific Private Clinic, Queensland, Australia.

DISCLOSURES. This research was part funded by an Australian Research Council linkage grant and a Smart Futures Co-Investment Grant. Dr Wearing is funded through a Smart Futures Fellowship, Department of Employment, Economic Development and Innovation, Queensland Government. The authors declare no conflicts of interest, financial or otherwise.

* Correspondence, proof reading, and reprint requests to: Scott C. Wearing

Faculty of Health Sciences and Medicine Bond University Gold Coast Qld 4229 AUSTRALIA Telephone: +61 7 5595 4417 Facsimile: +61 7 5595 1652

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Summary

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 27.5 kgm-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=.009) and following (t18= -4.87, P