INJURIES IN PROFESSIONAL RUGBY UNION: A STUDY OF FIVE YEARS OF INJURY DATA WITH TRAINING LOADS AND TRAVEL AS CO-VARIATES Dr Stephen Kara FRNZCGP / Dip Sports Med / Dip Obs. A thesis submitted to Auckland University of Technology in fulfilment of the requirements for the degree of Master of Philosophy (MPhil) August 2013 Faculty of Health and Environmental Sciences TABLE OF CONTENTS Attestation of authorship ........................................................................................................... 4 Candidate contributions to co-authored papers .......................................................................... 5 Acknowledgements .................................................................................................................... 6 Ethical approval ........................................................................................................................ 7 Abstract .................................................................................................................................... 8 Chapter 1 .................................................................................................................................. 9 Introduction, rationale for the studies based on critique of the literature, and structure of the thesis (Preface) ............................................................................................................................. 9 Background ................................................................................................................. 9 Rationale for the studies based on the critique of the literature ........................................ 10 Structure of the thesis ................................................................................................. 15 Chapter 2 ................................................................................................................................ 17 Epidemiological injury data from Super 14 Rugby Union – an observational study over five years (2006-2010) ...................................................................................................................... 17 Overview ................................................................................................................... 17 Introduction .............................................................................................................. 17 Methods .................................................................................................................... 18 Results ...................................................................................................................... 20 Discussion ................................................................................................................. 24 Conclusions ............................................................................................................... 27 Chapter 3 ................................................................................................................................ 28 The temporal effect of prior cumulative team training and match-load and acute training load on in- season injury risk in elite contact sports ................................................................................ 28 Overview ................................................................................................................... 28 Introduction .............................................................................................................. 28 Methods .................................................................................................................... 29 Results ...................................................................................................................... 32 Discussion ................................................................................................................. 34 Conclusions ............................................................................................................... 36 Chapter 4 ................................................................................................................................ 37 The effect of travel on injury risk – how much is this a factor? ................................................ 37 Overview ................................................................................................................... 37 Introduction .............................................................................................................. 37 Methods .................................................................................................................... 38 Results ...................................................................................................................... 40 Discussion ................................................................................................................. 43 Conclusions ............................................................................................................... 44 Chapter 5 ................................................................................................................................ 45 Discussion and conclusions ................................................................................................. 45 Limitations ................................................................................................................ 46 Future directions ....................................................................................................... 46 Key findings .............................................................................................................. 47 References ...................................................................................... 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Appendix 1 .............................................................................................................................. 55 Epidemiological studies from rugby union ............................................................................ 55 Appendix 2 .............................................................................................................................. 70 Summary of studies assessing injury risk as a function of load in contact running team sports .... 70 1 Appendix 3 .............................................................................................................................. 79 Summary of studies assessing the effect of airline travel and sleep deprivation on performance .. 79 Appendix 4 .............................................................................................................................. 85 AUT Ethics Committee approval – October 2011 .................................................................. 85 Appendix 5 .............................................................................................................................. 87 Health and Disability Ethics Committee approval – 22 July 2011 ............................................ 87 LIST OF FIGURES Figure 1.1: The relationship between training load, training phase and likelihood of injury in elite collision sport athletes. Reproduced from Gabbett1 with permission. ........................ 12 Figure 1.2: Overview of thesis chapter flow. .................................................................................. 16 LIST OF TABLES Table 2.1: Player characteristics (mean ±SD) for five years of rugby union play. ................................ 19 Table 2.2: Match and training injuries per season. ........................................................................... 20 Table 2.3: Injury counts according to playing position per year. ........................................................ 21 Table 2.4: Injury counts for incidence type and mechanism according to playing position (injuries adjusted for the number of playing positions in each positional group). .................... 22 Table 2.5: Injuries according to anatomical site. .............................................................................. 23 Table 2.6: Injury severity by prevalence per year. ........................................................................... 23 Table 2.7: Injury duration (mean ±SD) according to anatomical site. ................................................. 24 Table 3.1: 10-day cumulative smoothed daily team load and acute daily team load (intensity-minutes) over five years (mean ±SD). ................................................................................ 32 Table 3.2: Match and training-related injuries in each season. .......................................................... 33 Table 3.3: Effect of 2 SD of 10-day cumulative smoothed daily load expressed as a factor effect on match-related injuries. ........................................................................................ 33 Table 3.4: Effect of 2 SD of actual daily load and of 10-day cumulative smoothed daily load expressed as factor effects on training-related injuries. .............................................................. 34 Table 4.1: Location, match-related injuries and cumulative smoothed daily team load from 2006-2010 (mean ±SD). ...................................................................................................... 40 Table 4.2: Difference between locations on match-related injury data expressed as a factor effect (using a fixed time constant of 10 days for training load).