Study of Lateral Epicondylitis Using Biomechanical and Ultrasonographic Image Analysis

  • 李 淑雅

Student thesis: Doctoral Thesis

Abstract

The use of awkward wrist postures and unskilled techniques might induce lateral epicondylitis which then leads to changes in muscular performances in functional activities and also alters the ultrasonographic (US) characteristics of the common extensor tendon Obtaining more comprehensive information about the dynamic performances of the wrist muscles US characteristics and biomechanical properties of the tendon would improve current understanding of the pathology of tendinopathy This study thus first investigated the effects of coupling posture and movement velocity on the dynamic performances of the wrist muscles via a custom-made bi-planar isokinetic dynamometer Thirty subjects were recruited to perform the isokinetic testing The muscle activity of the extensor digitorum communis (EDC) normalized peak torque (PT) of extensors and ratio of normalized PT between wrist extensors and flexors were all greater in the neutral position (NP) than in radial deviation (RD) and ulnar deviation (UD) in all isokinetic contractions Nevertheless a significantly higher ratio of muscle activity between EDC and flexor digitorum superficialis (FDS) and the ratio of normalized PT between wrist extensors and flexors were found at the slow velocity in all isokinetic contractions The coupling postures and movement velocity of the wrist joint should thus be considered as influential factors which might alter the dynamic performances and may result in further injury of the elbow joint Secondly this study investigated the relationship between the dynamic muscular performances and US characteristics in lateral epicondylitis patients Nineteen healthy subjects and nineteen lateral epicondylitis patients were recruited to perform the isokinetic testing and measure the US characteristics of the common extensor tendon The patient group had the higher normalized PT of wrist extensors and wrist flexors during the isokinetic contraction The patient group also showed decreased co-activation between EDC and FDS during the isokinetic contractions and had significantly lower echo intensity of the common extensor tendon Furthermore the echo intensity was significantly correlated with the normalized PT of wrist extensors under RD during the isokinetic contraction in the patient group Therefore the non-invasive US factor presented in this work may provide the useful information about the dynamic performances of wrist extensors in lateral epicondylitis Thirdly the purpose of this study was to investigate the dynamic changes in histopathology biomechanical properties echo intensity and US features in the collagenase-induced tendinopathy model of rat Achilles tendons and to examine the associations among these features Forty-two rats received an ultrasound-guided collagenase injection on their left Achilles tendons with needle puncture on the right ones as the control At four eight and twelve weeks of post-injury the tendons were examined via measuring biomechanical properties histopathological and US characteristics The injured tendons showed significantly higher histopathological scores lower Young’s modulus and higher US feature scores than the control ones throughout the study Up to week 12 all injured tendons showed defective healing The biomechanical properties correlate well with the findings of echo intensity and the US feature scores The neovascularization score had a significant negative linear association with the failure stress and Young’s modulus Maximum normalized echo intensity had a borderline negative linear association with stiffness Therefore the neovascularization and maximum normalized echo intensity are critical factors to alter the mechanical properties of tendons The knowledge obtained in this study may provide evidence-based data to better understand the pathology of tendinopathy since this can provide biomechanics and US information to assess and treat the tendinopathy in clinics
Date of Award2016 Dec 2
LanguageEnglish
SupervisorFong-chin Su (Supervisor)

Cite this

Study of Lateral Epicondylitis Using Biomechanical and Ultrasonographic Image Analysis
淑雅, 李. (Author). 2016 Dec 2

Student thesis: Doctoral Thesis