The Development of a Qualitative Protocol to Analyse the Tackle in Rugby Union Football Trevor N. Savage A thesis submitted in fulfilment of the requirements for the degree of Master of Science School of Risk and Safety Science Faculty of Science University of New South Wales Australia August, 2011 ii ORIGINALITY STATEMENT I hereby declare that this submission is my own work and, to the best of my knowledge, it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged. Signed: ……………………………………………........... Date: …………………………………………….............. iii COPYRIGHT STATEMENT ‘I hereby grant the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I have either used no substantial portions of copyright material in my thesis or I have obtained permission to use copyright material; where permission has not been granted I have applied/will apply for a partial restriction of the digital copy of my thesis or dissertation.' A number of figures have been removed from this thesis because of copyright restrictions. The reference to the figures has been retained. Signed ……………………………………………........................... Date …………………………………………….............................. AUTHENTICITY STATEMENT ‘I certify that the Library deposit digital copy is a direct equivalent of the final officially approved version of my thesis. No emendation of content has occurred and if there are any minor variations in formatting, they are the result of the conversion to digital format.’ Signed ……………………………………………........................... Date …………………………………………….............................. iv ABSTRACT This thesis describes the development of a protocol to analyse the tackle in rugby union. The tackle is a collision event between a Ball-carrier and one or more opponents. The most frequently occurring match event, it has been consistently associated with a high risk of injury. Quantitative investigations of skill and injury in the tackle are hampered by its multi-factorial nature. A reliable qualitative protocol, prepared through a systematic and repeatable framework, represents a potential method of collecting information to narrow the focus for future investigation. A qualitative analysis protocol was developed to assess the tackle through evaluation of 107 mostly nominal fields. Fields were developed in consultation with epidemiological data, coaching literature, and applying biomechanical and qualitative skill analysis frameworks to identify aspects of skill and injury. The reliability of the analysis protocol was then assessed in two inter-rater reliability (IRR) studies. The results of the first IRR study were reviewed at a meeting of an expert panel and the protocol was modified to improve agreement before being tested in a second IRR study. In the first IRR study, substantial agreement (>70%) was obtained in 24 fields. Agreement amongst participants for medical events was almost perfect (91%) and agreement identifying a tackle according to the study definition was 74%. The mean agreement in all fields was moderate (61%). Slight agreement was observed for identifying the body region struck and the direction of travel of the players following the impact. The timing of analysis was identified as a potential reason for poor agreement. The results of the second IRR study suggested that providing a specific temporal reference for observations improved agreement in some fields and substantial agreement was observed in 48 fields. There was still disagreement in some important fields of the protocol. Following operational modifications, the protocol was used to code 6,618 tackles in a larger study of tackling technique and v injury risk. A sample analysis of 100 tackles is presented to demonstrate the utility of the protocol. Few qualitative technique analyses have described the development of the analysis method or examined IRR following changes to improve agreement. The results of this research indicate that the general agreement between raters using this protocol was moderate, and care needs to be taken in defining the variables used. vi “If we ignore the things that we cannot measure, then we cannot fully understand what we are researching” Soshanna Soafer, 1999 “Not everything that can be counted counts, and not everything that counts can be counted” William Bruce Cameron, 1963 vii An elementary tackle in rugby union involving a Ball-carrier and one Tackler viii RESEARCH BACKGROUND AND ACKNOWLEDGEMENTS It was my father who first gave me an interest in the world around me, my daughter who continues to enlighten and inspire me, particularly to ask ‘why’ and my undergraduate lecturer in biomechanics who gave me first the interest and then the opportunity to perform research in this field. The Rugby Union Injury Surveillance Study (RUISS) was the catalyst for my research and the research of our group in the tackle. The necessity of researching injury aetiology in the tackle evolved from RUISS, for which I was Project Officer at the University of New South Wales (UNSW) between 2002 and 2006. The results of RUISS confirmed the observations of numerous concurrent studies by identifying an apparently disproportionate incidence of injuries occurring during the tackle. During my discussions with the rugby faithful of the Sydney grade competition, conversations with medical staff and whilst collecting match video tapes from the bemused general managers of rugby clubs, it became clear to me that there was a widespread interest in investigating and addressing this problem. At the time that this research commenced in March 2006, a limited number of studies had measured tackle impact forces and physiological responses to the tackle, but there had been no attempt to describe the tackle event comprehensively. The limitations of motion analysis and obvious ethical restrictions meant that tackle injury could not be investigated in the laboratory using ‘traditional’ research methods. An alternative had to be found. Qualitative analysis seemed well placed for such an investigation because of its flexibility and utility in narrowing the focus of investigation. However there is was also awareness of addressing the perceived bias of qualitative analysis through constructing an analysis protocol that was systematic in both development and application. This thesis describes the development of a qualitative analysis protocol to analyse the tackle in rugby union. The development of the protocol was undertaken by a ix research group directed by Associate Professor Andrew McIntosh at UNSW in collaboration with the Rugby Football Union, England (RFU). Criteria to assess tackling skills were developed independently by each group. Following significant investigation, discussion and deliberation, these criteria were combined to instigate a reliable and valid method of analysis for future research. As a member of the research group at UNSW, I was actively involved in the development of the tackle analysis protocol and discussions of the results obtained in the inter-rater reliability (IRR) studies. I developed and co-ordinated the IRR studies under the direction of Assoc. Prof. McIntosh. I am indebted to the supererogatious volunteers of the Sydney Rugby Community who assisted with RUISS and the tackle study. I also acknowledge the contribution of the RFU team to this project, particularly Dr. Simon Kemp for his interest in my work and friendship. During my time at UNSW I was fortunate to work with very talented and wonderful people. Research can be a hard slog that was often made easier through their camaraderie. My contribution to the work and dynamic of our research group from 2002 and 2008 is a proud achievement in my career. I should like to make mention of my supervisor, Assoc. Prof. McIntosh, and particularly my co-supervisor, Dr. Bertrand Fréchède, for their guidance and support over the entire period and not only the period of candidature. I would also like to thank DEb and Nicole for their valuable comments on the draft thesis. To my other colleagues and friends from the former biomechanics research group and the former School of Risk and Safety Sciences at UNSW, cheers cobbers. To my family for their love and support, particularly Nicole, who has given up so much and placed many things on hold to join me in Australia, Bridie, my daughter whom I love dearly, and my parents who have contributed much to my person. There have been times where I stared for hours blankly at a computer screen wondering where and how to start and all and sundry have been expected to accommodate the reciprocal effects of hitting the pause button