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  • March 21, 2019
  • Pietrosimone, Laura
    • Affiliation: School of Medicine, Department of Allied Health Sciences, Curriculum in Human Movement Science
  • Laura Stanley Pietrosimone: Loading Characteristics and Responses in Male Athletes with Patellar Tendinopathy (Under the direction of Darin A. Padua) Abstract Context: Clinical management of tendinopathy is difficult, as tendon pathoetiology occurs on a continuum with inconsistent associations between structural pathology and pain. Tendon is highly responsive to mechanical load; however, load mismanagement can trigger homeostatic imbalances that lead to the development of tendinopathy. There is a need to characterize loading profiles and responses of individuals along the tendinopathic continuum to inform improved clinical management strategies. Objective: To evaluate differences in biomechanical and loading volume profiles and to determine the effects of an acute bout of patellar tendon isometric loading exercise on lower extremity landing biomechanics in male athletes with patellar tendinopathy. Participants: 43 male athletes with and without unilateral patellar tendinopathy. Interventions: All participants (SYM, ASYM, CON) performed double- and single-limb jump-landing tasks and one-week physical activity monitoring period. Additionally, participants in the SYM and ASYM groups underwent a randomized cross-over protocol on two additional testing days to examine the acute effects of an isometric patellar tendon loading exercise protocol on landing biomechanics. Main Outcome Measures: Loading magnitude variables included tri-planar hip and knee kinematics, kinetics, and energetics for the involved limb. Load frequency and duration variables included steps/day and amount of moderate-to-vigorous-physical activity/day, respectively. Load volume was estimated from load magnitude and frequency variables using validated equations. Results: SYM participants demonstrated patterns of under-loading, specifically in sagittal plane knee motion, patellar tendon force, and energy absorption during landing, and reduced load volume, compared to CON participants. There was no evidence of over-loading on any load magnitude, frequency, or duration variable for the ASYM participant. There was no acute effect of the isometric exercise protocol on any biomechanical measure for both the SYM and ASYM groups. Conclusions: Load magnitude, frequency, duration, and volume are all important metrics to measure and monitor in athletes at different stages of the continuum of patellar tendinopathy. Future research should evaluate the effects of isometric exercise protocols on movement profiles using longer duration exercise prescription and on individuals with higher magnitudes of tendon pain. Future research should continue to develop load monitoring strategies to improve tissue capacity and self-reported function in individuals with patellar tendinopathy.
Date of publication
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Rights statement
  • In Copyright
  • Docking, Sean
  • Berkoff, David
  • Padua, Darin
  • Blackburn, Jonathan
  • Wikstrom, Erik
  • Doctor of Philosophy
Degree granting institution
  • University of North Carolina at Chapel Hill Graduate School
Graduation year
  • 2018

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