S d Medic

aA

d

4

Sw

S

drhttp(Ajpu>wusCwdttawcrcHwTai

d

4

LAo

A

1

2

V

tahemwSiiSt((GcABtatrdtBmp

d

4

18 Abstracts / Journal of Science an

discussion of how the Australian Medical Profession andSADA may work together to address this issue.

oi:10.1016/j.jsams.2008.12.046

6

tiffness of the human Achilles tendon is altered in peopleith Achilles tendinopathy

. Child ∗, K. Crossley, A. Bryant, R. Clark

The University of Melbourne, Australia

Introduction: Achilles tendinopathy is known to be aebilitating condition that is associated with tendon mate-ial deterioration. However, the mechanical behaviour of theuman Achilles tendon in people with Achilles tendinopa-hy is unknown. The purpose of this study was to comparehe stiffness of the human Achilles tendon in vivo in peo-le with and without tendinopathy. Methods: Sixteen males26–55 years) who had clinical signs and symptoms ofchilles tendinopathy (>3 months) together with 13 unin-

ured males, matched for weekly running volume and age,articipated in the study. All participants were screenedsing greyscale and Doppler ultrasound and were running20 km/week. Maximal isometric plantarflexion contractionsere performed on a calf-raise apparatus with a load cellnder the foot plate whilst synchronous real-time ultra-onography of the triceps surae aponeurosis was recorded.onnective tissue length (Lo) of the triceps surae complexas measured and Achilles tendon strain was calculated byividing aponeurosis displacement (�L, mm) during plan-arflexion by Lo. Achilles tendon stiffness (N mm−1) washen calculated by dividing Achilles tendon force (N) byponeurosis displacement. Results: Achilles tendon stiffnessas significantfy (p < 0.05) lower in the tendinopathy group

ompared to the control group. Conclusion: The tempo-al relationship between altered stiffness and tendinopathyannot be determined using a cross-sectional study design.owever, our finding of reduced tendon stiffness associatedith tendinopathy may have important clinical implications.hese results may support current clinical approaches to man-

gement of Achilles tendinopathy; whereby tendon loading isncreased in order to enhance tendon mechanical properties.

oi:10.1016/j.jsams.2008.12.047

Mt

N

1

2

etl1fr

ine in Sport 12S (2009) S1–S83

7

ong-term eccentric and concentric exercise increasechilles tendon blood flow but do not produce evidencef tendinosis in rats

. Scott 1,∗, L. Koglin 1, K. Khan 1,2

University Of British Columbia, CanadaCentre for Hip Health and Musculoskeletal Research,ancouver Coastal Health Research Institute, Canada

Introduction: Evaluating new treatments for overuseendinopathy has been hampered by the lack of a readilyvailable laboratory model which duplicates the features ofuman tendinosis. The goal of the current study was toxamine the suitability of the rat Achilles as a tendinopathyodel. We hypothesized that running uphill, but not downhill,ould cause evidence of Achilles tendinosis. Methods: Maleprage–Dawley rats were placed on a daily treadmill train-

ng program, 1 h/day, 1 km/h, for 12 weeks. The treadmill wasnclined 10◦ downhill (n = 6 rats) or 10◦ uphill (n = 6 rats).edentary rats were used as controls (n = 8). After 12 weeks,

he Achilles tendon was evaulated by grey scale ultrasound35 MHz), laser Doppler flowmetry and tissue spectroscopy3 mm depth), and histology (H&E, Alcian blue). Results:reyscale ultrasound revealed no tendon pathology in exer-

ised or sedentary Achilles tendons. There was no change inchilles tendon oxygen saturation among the three groups.asal blood flow was significantly increased in the Achilles

endon of both running groups compared to controls (158nd 166% increase in downhill and uphill runners, respec-ively, p < 0.05). Histological analysis using the Bonar scaleevealed no significant tendinosis in any of the examined ten-ons. Conclusions: The rat Achilles tendon did not developendinosis in response to chronic uphill or downhill exercise.asal blood flow was increased by exercise irrespective of theode of training (uphill vs. downhill) and likely represents a

hysiological response.

oi:10.1016/j.jsams.2008.12.048

8

odelling activity dependent diametral strain in Achillesendon

. Stevenson 1, J. Smeathers 1,∗, N. Grigg 1, S. Wearing 2

Queensland University of Technology, AustraliaUmversiry of Strathclyde, Scotland, United Kingdom

The Achilles tendon is a viscoelastic tissue that typicallyxperiences 3500 ± 1700 cyclic loads per day from intermit-ent periods of ambulatory activity. Typically, peak tensile

oads exceed three times body weight and average about500 N during stance, which lasts for approximately 0.6 s,ollowed by a 0.2 s unloaded swing phase. Viscoelastic mate-ials respond to external load (stress) in a time-dependent