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Biomechanical Performance Factors of Slalom Water Skiing

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Biomechanical Performance Factors of Slalom Water Skiing BIOMECHANICAL PERFORMANCE FACTORS OF SLALOM WATER SKIING A Thesis Presented to The Faculty of Graduate Studies of The University of Guelph by JORDAN BRAY-MINERS In partial fulfillment of requirements for the degree of Master of Applied Science August, 2011 © Jordan Bray-Miners, 2011 ABSTRACT BIOMECHANICAL PERFORMANCE FACTORS OF SLALOM WATER SKIING Jordan Bray-Miners Advisor: Dr. R John Runciman University of Guelph, 2011 The instrumentation and methodology of this study provided quantitative data for a group of six advanced slalom skiers. Rope load, skier velocity, ski roll, ski acceleration and ski deceleration were calculated during the deep water start and cutting portion of a slalom run. Four different ski designs were tested in order to determine if the test subjects were able to achieve a different level of performance on each ski. Through a statistical analysis there was enough evidence to suggest that a different performance was achieved between the skis, for rope load and peak roll. There was also enough evidence to suggest that the skiers were achieving different overall levels of performance. The analysis procedure of this study achieved the goal of proving that it could be used to improve coaching capabilities and product design in the water ski industry. Acknowledgments I would like to start off by thanking my advisor, John Runciman. Without his passion to take research “outside the box” this project would never have been initiated. He constantly assured me that I was doing a good job and showed endless confidence in my personal abilities. There have been several other faculty and staff within the School of Engineering that have had a significant impact on my success. Nate Groendyk is someone who went above and beyond his job as a technician to help develop and troubleshoot my electrical components. More importantly he designed the hardware and software for one of my communication systems, which was a critical component to the success of my test days. Throughout this study I had the unique experience of working with human participants, who were willing to “donate their body to science”. They volunteered their time out of interest and love for the sport of slalom skiing. For that I would like to thank Leo, Hugh, Colin, Blake, Aaron and Kyle. Leo was not only one of my human participants but he also is the owner of an amazing water skiing facility, Lighthouse Lake Water Sports Centre. They allowed me to run all of my test days at their facility. He and his wife, Deb, provided us with great hospitality while we were there. Table of Contents Acknowledgments..............................................................................................................iii Table of Contents............................................................................................................... iv List of Figures.................................................................................................................... vi List of Tables ...................................................................................................................... x Chapter 1: Introduction and Background............................................................................ 1 1.1 The Basics of Water Skiing ................................................................................ 2 1.2 Coaching ............................................................................................................. 6 1.3 Instrumentation ................................................................................................... 7 1.4 Methodology....................................................................................................... 8 1.5 Thesis outline.................................................................................................... 11 Chapter 2: Literature Review............................................................................................ 13 2.1 Literature Review.............................................................................................. 14 Chapter 3: Methods and Instrumentation used for Biomechanical Analysis of Slalom Water Skiing............................................................................................. 23 Abstract......................................................................................................................... 25 1 Introduction and Background ............................................................................... 26 2 Methods................................................................................................................. 30 3 Results................................................................................................................... 39 4 Discussion............................................................................................................. 44 5 Conclusion ............................................................................................................ 47 6 Acknowledgements............................................................................................... 48 7 References............................................................................................................. 48 Chapter 4: Water Skiing Biomechanics a Study of Advanced Skiers .............................. 49 Abstract......................................................................................................................... 51 1 Introduction and Background ............................................................................... 52 2 Methods................................................................................................................. 54 3 Results................................................................................................................... 61 4 Discussion............................................................................................................. 69 5 Conclusion ............................................................................................................ 76 6 Acknowledgements............................................................................................... 78 7 References............................................................................................................. 78 Chapter 5: Biomechanical Analysis of Slalom Water Skiing: an in-depth look at a slalom cut.............................................................................................................. 79 Abstract......................................................................................................................... 81 1 Introduction........................................................................................................... 82 2 Methods................................................................................................................. 85 3 Results................................................................................................................... 89 4 Discussion........................................................................................................... 105 5 Conclusion .......................................................................................................... 111 6 Acknowledgements............................................................................................. 112 7 References........................................................................................................... 112 Chapter 6 – Conclusion and Future Considerations ....................................................... 113 iv 6.1 Conclusion and Future Considerations ........................................................... 114 References....................................................................................................................... 116 Appendices...................................................................................................................... 119 Appendix A: Sample calibration procedure for the load transducer........................... 120 Appendix B: Sample qualitative survey ..................................................................... 122 Appendix C – Ski Survey Results............................................................................... 127 v List of Figures Chapter 3 Figure 1: a) IMU system in its housing strapped to the front of one of the skis. b) IMU and its transceiver system mounted in plastic box....................................... 32 Figure 2: GPS unit wrapped in plastic and mounted in the helmet ................................. 33 Figure 3 - Diagram of slalom course including entrance gates ( x ), skier path and buoys 1 – 6 ( o ) and sample dimensions [“International Waterski & Wakeboard”, 2010]............................................................................................... 37 Figure 4: Example rope load, skier velocity and boat velocity data for one test run. Major activities include: start up (SU), entrance cut (EC), slalom turns (ST) and boat turn around (BTA).................................................................................. 40 Figure 5: Example ski pitch, roll and heading data for one test run. Major activities include: start up (SU), entrance cut (EC), slalom turns (ST) and boat turn around (BTA)........................................................................................................ 41 Figure 6: Example ski acceleration/deceleration data for one test run. Major activities include:
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