A novel application of strain sonoelastography can detect changes in Achilles tendon elasticity during isometric contractions of increasing intensity

Research output: Contribution to journalArticlepeer-review

Authors

  • Alessandro Schneebeli
  • Filippo Del Grande
  • Corrado Cescon
  • Ron Clijsen
  • Marco Barbero

External organisations

  • University of Applied Sciences and Arts of Southern Switzerland
  • Servizio di Radiologia, Ospedale Civico e Italiano, Ente Ospedaliero Cantonale (EOC)
  • University College Physiotherapy, Thim van der Laan AG
  • Vrije Universiteit Brussel

Abstract

Background: Mechanical and morphological properties of the Achilles tendon are altered in disease and in response to changes in mechanical loading. In the last few years different ultrasound based technologies have been used to detect tendon mechanical properties changes mainly in resting condition. Therefore the aim of this study was to evaluate if strain sonoelastography can identify changes in Achilles tendon elasticity during isometric contractions of increasing intensity.

Methods: This cross-sectional study enrolled 37 healthy volunteers (19 women) with mean (±SD) age of 27.1 (±7.0) years between January and June 2017. Strain sonoelastography images of the Achilles tendon were acquired during an isometric ramp force (0 kg, 0.5 kg, 1 kg, 2 kg, 5 kg and, 10 kg). An external reference material was used to provide a comparison between the examined tissue and a material of constant elasticity. Friedman test with post hoc pairwise comparison were used to determine the correlation between the difference contraction levels.

Results: The median and interquartile range (IQR) values for the strain ratio were 1.61 (1.5-2.9) in a relaxed state and 1.30 (1.07-2.02), 1.00 (0.76-1.66), 0.81 (0.70-1.19), 0.47 (0.39-0.73) and 0.33 (0.28-0.40) for 0.5 kg, 1 kg, 2 kg, 5 kg and 10 kg, respectively revealing increased tendon hardness with increasing contraction intensities. Friedman test revealed significant differences (p < 0.05) in the strain ratio between all contractions except between 0.5 kg - 1 kg (p = 0.41); 1 kg - 2 kg (p = 0.12) and 5 kg - 10 kg (p = 0.12).

Conclusion: Strain sonoelastography can detect changes in Achilles tendon elasticity between different contraction intensities. The results provide an original force-elasticity curve for the Achilles tendon in a healthy, asymptomatic population.

Details

Original languageEnglish
Article number30
Number of pages7
JournalJournal of Foot and Ankle Research
Volume12
Issue number1
Publication statusPublished - 21 May 2019

Keywords

  • Achilles tendon, Elasticity, Strain sonoelastography

ASJC Scopus subject areas