LOWER EXTREMITY BIOMECHANICS IN THOSE WITH PATELLAR TENDINOPATHIES AND THE EFFECTS OF PATELLAR TENDON STRAPPING by ADAM BENJAMIN ROSEN (Under the Direction of CATHLEEN BROWN CROWELL) ABSTRACT Patellar Tendinopathy (PT) is a common degenerative condition in physically active populations. Knowledge regarding the biomechanics of landing in populations with symptomatic PT is limited. The purpose of this dissertation was to identify the kinematics, kinetics and muscle activation strategies associated with patellar tendinopathies, as well as to assess the effectiveness of patellar tendon straps on altering each of those biomechanical factors. Sixty recreationally active individuals participated in this study. Thirty had current signs and symptoms of PT, including self-reported pain within the patellar tendon during loading activities for at least three months and ≤80 on the Victorian Institute of Sport Assessment Scale-Patella (VISA-P). Thirty healthy participants (Con) with no history of PT or other knee joint pathology were matched to the PT group by gender, age, height, and weight. All participants completed five trials of 40 cm two-legged drop-jumps in patellar tendon strap and no-strap conditions. Kinematics, kinetics and electromyography were recorded. Multiple mixed model two-way ANOVAs were performed to determine the effect of PT status and bracing condition on each of the dependent variables. Participants with PT displayed significantly decreased peak hip (PT=59.2±14.6º, Con=67.2±13.9º, p=.03) and peak knee flexion angles (PT=74.8 ±13.2º, Con=82.5±9.0º, p=.01), as well as decreased maximum angular displacement in the sagittal plane at the hip (PT=49.3±10.8º, Con=55.2 ±11.4, p=.04) and knee joints (PT=71.6±8.4º, Con=79.7±8.3º, p<.001) compared to the control group. When wearing the strap, PT participants reported significantly (p=.03) decreased pain (21.3±20.2mm) compared to the non- strapped condition (28.0±22.1mm). PT participants during the strapping condition had a decreased (p=.05) peak adduction moment (-0.10±0.11 Nmkg-1) compared to controls (- 0.17±0.16 Nmkg-1), and no strapping conditions (PT= -0.16±0.16 Nmkg-1, Con= -0.16±0.15 Nmkg-1). The healthy participants with no strap (2.35 ± 1.61%) had a greater rectus femoris peak EMG compared to the control while wearing the strap (2.04 ± 1.35%) and the PT conditions (no strap= 2.09 ± 1.31%, strap=2.18 ± 1.59%). The results indicate that those with PT demonstrate alterations in movement strategies during landings. Moreover, patellar tendon straps appear to reduce pain acutely, possibly through altering lower extremity kinetics. INDEX WORDS: knee pain, jumper’s knee, braces, joint kinetics, angular kinematics LOWER EXTREMITY BIOMECHANICS IN THOSE WITH PATELLAR TENDINOPATHIES AND THE EFFECTS OF PATELLAR TENDON STRAPPING by ADAM BENJAMIN ROSEN BS, University of Delaware, 2006 MS, University of Delaware, 2008 A Dissertation Submitted to the Graduate Faculty of the University of Georgia in Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY ATHENS, GEORGIA 2014 © 2014 ADAM BENJAMIN ROSEN All Rights Reserved LOWER EXTREMITY BIOMECHANICS IN THOSE WITH PATELLAR TENDINOPATHIES AND THE EFFECTS OF PATELLAR TENDON STRAPPING by ADAM BENJAMIN ROSEN Major Professor: CATHLEEN BROWN CROWELL Committee: KATHY J. SIMPSON SEOCK-HO KIM Electronic Version Approved: Julie Coffield Interim Dean of the Graduate School The University of Georgia August 2014 ACKNOWLEDGEMENTS I would like to thank a number of people who have supported me throughout this endeavor. First, I would like to thank my committee members. Drs. Cathleen Brown Crowell, Kathy J. Simpson, and Seock-Ho Kim have provided continual guidance, expertise, and countless hours in assisting in the completion of my PhD. Their help has been instrumental in my success at UGA and finishing my dissertation project. I would particularly like to thank Dr. Cathleen Brown Crowell, who has acted as my major professor, advisor and mentor. Her leadership and guidance has been crucial in accomplishing my goals. I am grateful for having the opportunity to study and learn from her throughout my doctoral training. I would also like to thank my wife Marisa for her unconditional love and support through this entire process, without her I would have never been able to achieve this. Finally, I would like to thank my family and friends for all their encouragement and advice during this time. iv TABLE OF CONTENTS Page ACKNOWLEDGEMENTS ........................................................................................................... iv LIST OF TABLES ....................................................................................................................... viii LIST OF FIGURES .........................................................................................................................x CHAPTER 1 INTRODUCTION .........................................................................................................1 A Background and Rationale ..................................................................................1 B. Statement of the Problem/Purpose .....................................................................2 C. Specific Aims .....................................................................................................4 D. Research Questions ............................................................................................4 E. Hypothesis Justifications ....................................................................................7 F. Research Hypotheses ........................................................................................10 G. Definitions ........................................................................................................13 H. Assumptions ......................................................................................................14 I. Delimitations ......................................................................................................15 J. Limitations..........................................................................................................15 2 LITERATURE REVIEW ............................................................................................17 A. Epidemiology ....................................................................................................18 B. Anatomy ...........................................................................................................19 C. Histopathology .................................................................................................22 D. Symptoms and diagnosis ..................................................................................22 v E. Self-report Tools ...............................................................................................25 F. Pathomechanics ................................................................................................26 G. Biomechanical Factors Associated with Patellar Tendinopathy ......................28 H. Treatment of Patellar Tendinopathy ................................................................32 I. Literature Review Related to Methods ...............................................................38 3 METHODS ..................................................................................................................44 A. Participants ........................................................................................................44 B. Sample Size Justification ..................................................................................46 C. Research Protocol .............................................................................................48 D. Instrumentation .................................................................................................48 E. Testing Procedures ...........................................................................................51 F. Data Reduction and Analysis............................................................................54 G. Statistical Analysis ...........................................................................................56 4 LOWER EXTREMITY KINEMATICS DURING A DROP-JUMP IN THOSE WITH PATELLAR TENDINOPATHY......................................................................58 A. Abstract ............................................................................................................59 B. Introduction ......................................................................................................61 C. Materials and Methods .....................................................................................62 D. Results ..............................................................................................................66 E. Discussion.........................................................................................................67 F. Conclusion ........................................................................................................73 5 PATELLAR TENDON STRAPS ACUTELY ALTER PAIN AND JOINT KINETICS IN THOSE WITH PATELLAR TENDINOPATHY ...............................80 vi A. Abstract ............................................................................................................81 B. Introduction ......................................................................................................82 C. Methods ............................................................................................................83