Transitioning to minimal running footwear; Implications for performance and running related injury when compared to conventional running shoes. Joe P. Warne For the award of PhD. 2014 Transitioning to minimal running footwear; Implications for performance and running related injury when compared to conventional running shoes. Joe P. Warne (BSc) For the award of PhD Dublin City University Supervisors: Dr. Giles Warrington / Dr. Kieran Moran School of Health and Human Performance July, 2014 Volume 1 (of 1). Declaration I hereby certify that this material, which I now submit for assessment on the programme of study leading to the award of PhD is entirely my own work, and that I have exercised reasonable care to ensure that the work is original, and does not to the best of my knowledge breach any law of copyright, and has not been taken from the work of others save and to the extent that such work has been cited and acknowledged within the text of my work. Signed: ____________ (Candidate) ID No.: ___________ Date: _______ Acknowledgements I must first thank Sandra for supporting me through this entire process. She has been the light at the end of each day and made the long road an amazing experience at all times. I must also thank my family for their continued support in whatever I do in life. They are a backbone in times of need and a steady hand to guide me when the path divides. They have been patient and understanding when juggling both a PhD and athletics career, and I could not have done this without them. In DCU I must thank my supervisors Dr Giles Warrington and Dr Kieran Moran, for their guidance and depth of knowledge when compiling this thesis. The PhD track is a steep learning curve, but both Giles and Kieran have kept me from stepping out of my lane. Their time and patience over the last four years was much appreciated. Dr Chris Richter, when you are not in the gym you have given me a lot of your time for data analysis and for this I am very grateful. A “thirty minute” programming session turned into a lot more than you bargained for, but I hope that it was worth it. There have been many other people who have helped me in the last four years to achieve this piece of work. They include; Stephen Cleary, John Fagan, Michelle Hone, Barry Smyth, Brian Gregan, Sharon Kilduff, Enda Murphy, Emma Whelan, Ciaran O’Cathain, Paul O’Connor, Des Earls, Darragh Greene, and probably others that I have missed – my apologies if this is the case. A special thanks to Professor Alan Nevill from the University of Wolverhampton, UK for his expert advice with statistical analysis during the final stages of each study. This work would not have come together without the long hours volunteered by my participants, and for this I can’t thank them enough. I hope that they have taken as much out of their individual experiences as I did out of the entire process. Table of Contents Declaration ........................................................................................................................ iii Acknowledgements ................................................................................................................... iv Table of Contents ........................................................................................................................ i Abstract ...................................................................................................................................... v List of Tables ............................................................................................................................. vi List of Figures .......................................................................................................................... viii Glossary of Terms...................................................................................................................... xi List of Abbreviations ................................................................................................................ xii List of Publications and Communications ............................................................................... xiii Conflicts of Interest ................................................................................................................. xiv Thesis Overview and Guidelines .............................................................................................. xv 1. Introduction .................................................................................................................... 2 1.1 Background and Justification .............................................................................................. 2 1.2 Aim and Objectives ............................................................................................................. 6 2. Review of Literature .................................................................................................... 8 2.1 Factors Related to Performance in Endurance Running ..................................................... 8 2.2 Running Biomechanics and Running Economy ................................................................. 10 2.2.1 Biomechanics Factors Associated with Running Economy ........................................ 12 2.2.2 Gait Changes and their Relationship to Running Economy ....................................... 15 2.2.3 Neuromuscular Factors Associated with Running Economy ..................................... 19 2.3 The Influence of Footwear on Running Economy ............................................................. 21 2.3.1 The Influence of Surface Hardness on Running Economy ......................................... 22 2.3.2. The Influence of Shoe Mass and Shoe Cushioning on Running Economy ................ 25 2.3.3 Elastic Energy Utilisation with Footwear ................................................................... 26 2.3.4 Habituation to Footwear ............................................................................................ 27 2.3.5 MFW Research with Regard to Running Economy .................................................... 28 2.4 Conclusion – Running Economy, Biomechanics, and Footwear ....................................... 30 2.5 Running Related Injury ...................................................................................................... 30 2.6 Running Biomechanics and Running Related Injury ......................................................... 38 2.6.1 Kinetic Factors and Running Related Injury ............................................................... 39 2.6.2 Kinematic Factors and Running Related Injury .......................................................... 44 2.6.3 Gait-retraining Models ............................................................................................... 54 i 2.6.4 Neuromuscular Control and Running Related Injury ................................................. 58 2.7 The Influence of Footwear on Injury and Running Biomechanics .................................... 59 2.7.1 Injuries in Various Footwear ...................................................................................... 62 2.7.2 Kinetic Changes with Footwear ................................................................................. 65 2.7.3 Kinematic Changes with Footwear ............................................................................ 71 2.7.4 MFW Design Considerations with Regard to Running Related Injury ....................... 74 2.7.5 The MFW Transition with Regard to Running Related Injury .................................... 75 2.8 Conclusion ......................................................................................................................... 76 3. The Transition Programme and Overview of Study Design .............................................. 79 3.1 A Transition Proposal ........................................................................................................ 79 3.2 Individual Study Aims and Objectives ............................................................................... 85 4. Study One – “Four weeks habituation to simulated barefoot running improves running economy when compared to shod running”. ...................................................................... 88 4.1 Introduction ...................................................................................................................... 88 4.2 Methods ............................................................................................................................ 90 4.2.1 Participants ................................................................................................................ 90 4.2.2 Experimental design ................................................................................................... 90 4.2.3 Running economy tests .............................................................................................. 91 4.2.4 Four week familiarisation phase ................................................................................ 92 . esting procedure – O2max ........................................................................................ 92 4.2.6 Data analysis for RE tests ........................................................................................... 92 4.2.7 Statistics ..................................................................................................................... 92 4.3 Results ..............................................................................................................................