The Development of a Novel Pitching Assessment Tool Richard Birfer, B. Kin (Honours Specialization) Submitted in partial fulfillment of the requirements for the degree of Master of science in Applied Health Sciences (Kinesiology) Faculty of Applied Health Science Brock University St. Catharines, ON © August 2019 i Abstract Posture based ergonomic assessment tools are widely used to evaluate posture and injury risk for many workplace/occupational tasks. To date, there is no validated equivalent that can be used to assess the posture of a pitcher during baseball pitching. Therefore, the purpose of this study was to develop an inexpensive tool which can allow for the rapid assessment of a pitcher’s posture at lead foot strike, and establish the inter- and intra- rater reliability of the tool. For this study, 11 participants threw 30 pitches (15 fastballs, 15 curveballs) off an indoor pitching. Full body 3D kinematics were measured using reflective markers attached to anatomical landmarks and rigid bodies attached to body segments using a 10-camera Vicon Motion Capture system along with two high-speed video cameras (rear and side view) to record each pitch during the experimental trials. The kinematic data was analyzed, after which the highest velocity fastball of each of the 11 pitchers was selected for further analysis. A Pitching Mechanics Tool was designed to evaluate 16 different parameters at lead foot strike. Each of the 16 parameters had posture ranges or categories established based on scientific literature. Six evaluators with at least five years of experience working with adult pitchers completed the Pitching Mechanics Tool. Findings showed moderate to good levels of repeatability across multiple sessions as well as across multiple evaluators. Additionally, PMT results suggested that 2D qualitative analysis is a viable alternative to 3D motion capture. Keywords: Pitching Mechanics, Three-Dimensional Motion Capture, Kinematics, Ergonomics ii Acknowledgment I would like to start off by thanking my two supervisors, Dr. Michael Holmes and Dr. Michael Sonne for their continuous guidance, support, and mentorship over the past two years. Thank you for working so diligently to answer all of my questions, both good and not so good, and for allowing a bunch of adult pitchers to throw a hard baseball at maximum effort inside the lab for the sake of science. My research has been able to open many career doors for me and I have learned a lot about both myself and the fields of biomechanics and ergonomics; for that, I thank you. To Ryan Bench, an undergraduate assistant who over the past year has grown into one of my good friends, thank you for spending countless hours in the lab with me, helping me with data collection, and realizing how truly excruciating pressing buttons on a computer can be - especially when things do not work according to plan. I would also like to thank my committee member Dr. Nicole Chimera; your contributions and insights have only strengthened my thesis project. Lastly, I would like to thank Logan McCall. You nearly sacrificed yourself to help me build an indoor mound. If you build it, they will come. iii Table of Contents Abstract ................................................................................................................................ ii Acknowledgements .............................................................................................................. iii List of Tables .........................................................................................................................vi List of Figured ....................................................................................................................... vii List of Abbreviations ............................................................................................................ viii Chapter 1: Introduction ......................................................................................................... 1 1.1 Background and Research Gaps ........................................................................................... 1 1.2 Research Questions ............................................................................................................... 3 1.4 Hypotheses ............................................................................................................................ 3 Chapter 2: Literature Review ................................................................................................. 5 2.1 Upper Extremity Injuries in Baseball ..................................................................................... 5 2.1.1 Elbow Anatomy and Injuries ...................................................................................... 6 2.1.2 Shoulder Anatomy and Injuries ......................................................................................... 7 2.1.3 Pitching Injuries in Baseball ....................................................................................... 9 2.2 Pitching Mechanics .............................................................................................................. 14 2.2.1 Pitching Delivery ...................................................................................................... 14 2.2.2 Fatigue’s Effect on Pitching Mechanics ................................................................... 18 2.3 Kinematic Risk Assessment Tools ........................................................................................ 21 2.3.1 RULA ......................................................................................................................... 23 2.3.2 REBA ......................................................................................................................... 26 2.3.3 Video and Computer-Based Observational Assessments ........................................ 29 2.4 Pitching Mechanics Assessment Tool.................................................................................. 31 2.4.1 Posture Assessment Software ................................................................................. 34 2.5 Three-Dimensional Kinematics ........................................................................................... 36 2.5.1 Methods of Kinematic Analysis ................................................................................ 37 2.6 Financial Implications and Market Needs ........................................................................... 41 2.6.1 Professional Level .................................................................................................... 41 2.6.1 Amateur Level .......................................................................................................... 42 Chapter 3: Methods ............................................................................................................. 45 3.1 Overview.............................................................................................................................. 45 3.1.1 Sample Size .............................................................................................................. 45 3.1.2 Experimental Setup .................................................................................................. 46 3.1.3 Experimental Trials .................................................................................................. 49 3.2 Pitching Mechanics Tool ...................................................................................................... 52 iv 3.3 Data Analysis ....................................................................................................................... 57 3.4 Statistical Analysis ............................................................................................................... 60 3.5 Results ................................................................................................................................. 62 3.5.1 Demographic ............................................................................................................ 62 3.5.2 Performance Analysis .............................................................................................. 63 3.5.3 3D Kinematic Analysis and Gold Standard Bin Selection ......................................... 65 3.5.4 Intra-Rater Reliability ............................................................................................... 67 3.5.5 Inter-Rater Reliability ............................................................................................... 69 3.5.6 Validity ..................................................................................................................... 71 3.6 Discussion ............................................................................................................................ 75 3.6.1 Main Findings ........................................................................................................... 75 3.6.2 Future Works ........................................................................................................... 85 3.7 Conclusion ........................................................................................................................... 87 References .......................................................................................................................... 88 Appendix A – Brock University REB Application .................................................................. 100 Appendix