ANALYZING THE UTILITY OF TENDON MECHANICAL PROPERTIES AND THEIR RELATIONSHIP WITH CLINICAL OUTCOME MEASURES FOR PATELLAR TENDINOPATHY
Date
2019-05
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Publisher
University of Delaware
Abstract
Patellar tendinopathy is a chronic overuse injury of the patellar tendon, which connects the kneecap to the lower leg. This injury most commonly presents in athletes who undergo repetitive jumping motions, especially elite volleyball and basketball players. Patellar tendinopathy presents in 44% and 32% of these cases, respectively, and it is estimated that 50% of affected individuals may be forced to retire from sport prematurely.
Patellar tendinopathy is characterized by an overall decrease in patellar tendon health. Patellar tendon health encompasses tendon structure, assessed via ultrasound imaging, symptom severity and duration, assessed by patient-reported outcome measures, and lower extremity function, assessed through squatting and jumping tests. Moreover, decreased patellar tenon health is associated with impairments in patellar tendon mechanical properties, such as shear modulus or viscosity. These mechanical properties are relatively new measures of tendon health, and it is not yet known how they might fit into the management of tendinopathies. Before making clinical applications, it may be of interest to determine if relationships exist between mechanical properties and other clinical outcome measures for patellar tendinopathy. Furthermore, mechanical properties should be considered in individuals with and without patellar tendinopathy, for the purpose of identifying changes with respect to injury.
Seventeen injured and thirteen uninjured participants completed the study. No statistically significant differences between shear modulus or viscosity were detected across cohorts; however, this study found significant differences in symptom severity, knee-related quality of life, kinesiophobia, and pain catastrophizing tendencies.
Moderate positive relationships were found in the uninjured cohort between shear modulus and functional performance via the single-leg countermovement jump (CMJ) and drop countermovement jump (Drop CMJ) tests. Moreover, moderate to strong positive relationships existed in the uninjured cohort between viscosity and CMJ and Drop CMJ heights. In the injured cohort, only a moderate positive relationship was detected between viscosity and CMJ height.
Based on the results of this study, it appears that the difference in relationships between injured and uninjured is due to confounds associated with injury. These may include pain, kinesiophobia, or muscle weakness or inhibition. Any one of these injurious impairments may be accounting for the changes in patellar tendon mechanical properties, so it is imperative that clinicians utilize a variety of clinical outcome measures on an individualized basis. This holistic approach may result in better outcomes for patients with patellar tendinopathy.
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Keywords
Tendon, Patellar tendinopathy