i FEET AND FOOTWEAR: FRIENDS OR FOES? By SIMON FRANKLIN, BSc. A thesis submitted to the University of Birmingham for the degree of DOCTOR OF PHILOSOPHY September 2017 School of Sport, Exercise and Rehabilitation Sciences College of Life and Environmental Sciences University of Birmingham September 2017 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. ii Abstract A third of over 65s have at least one fall per year whilst a quarter of over 45s endure foot pain. Footwear is associated with both fall risk and foot pain hence its investigation is of great importance. This thesis explores the potential benefits of minimalist footwear for the older adult population. Chapter 2 ascertained the kinematic and kinetic differences between walking barefoot versus in footwear whilst highlighting the limited research on minimalist footwear, older adults and muscle activity differences. Accordingly, Chapter 3 outlined that minimalist footwear is kinematically more similar to barefoot, irrespective of age, thus offering a viable alternative. Similarly, Chapter 4 showed walking in minimalist footwear and walking unshod exhibit similar lower leg muscle activation patterns whilst differences exist to conventional footwear. Chapter 6 demonstrated how increasing intrinsic foot strength improved functional and static balance whilst Chapter 7 showed promise for minimalist footwear improving foot strength, functional balance, balance confidence as well as reducing foot and joint pain in a sample of older adults. In conclusion, this thesis highlights the need for future work to continue to investigate minimalist footwear in both older adults and other age groups for benefits to stability, foot health and joint pain. iii Acknowledgements I would first like to acknowledge my supervisors, François and Michael, who gave me the opportunity to do this PhD which has helped me to develop as both an academic and a person. I could not have completed this PhD without the help and friendship of numerous people and I will try my best to cover as many of these people as possible. Firstly Borut, you helped me settle into the research group and office right from the first day and by the time you left you had become a great friend along with teaching me so much and in effect becoming my third supervisor! I tried to repay you with proof reading your endless supply of papers you impressively churned out and entertainment through my cycling failures and gymnastic attempts (!) but a huge thank you goes to you! Similarly Danique, I can’t repay you enough for your Matlab help along the way! It was great to have you both in the research group (along with Laura on the occasions she was around!) but you all set very high standards to follow including you Laura who have always been a fraction better than me right from our undergrad! Next I have to give a mention to the original great bunch of postgrads here when I first started. Benny, Fletchy, Ryan, Alex, Soden, Doris and Mike thanks for keeping me sane with our numerous barbeques (Fletchy and Ryan especially, Kings of the BBQ regardless of the time of year!), pool sessions (Benny, we need to add up the money and time we’ve spent around pool tables at Riley’s and the Soak the past 4 years!), squash games and general good times! Most of you have finished up and moved on but of course Alex you are still plodding on as you do but maybe we can graduate together if you’re not late to that as well! To all of the newer bunch, Stu, Steve, Jamo, Stocksy, Gav, Ste, Nathan, Brandon, Seabright, Sarah, Sardar, again thanks for the support and friendship along the way and particularly in the case of Seabright and Stu endless hours of priceless entertainment! A special shout out also has to go to all the SportexR football team mates over the years, I won’t name you all but you know who you are, definitely the best part of Mondays and Wednesdays if not the whole week. Save a iv space for me in next season’s champions league as an honorary team member? I don’t want to say goodbye just yet... Finally from the PhD setting I would like to thank the techies Steve, Dave, Andy, Manjit and all the admin staff for all your help fixing any problem I encountered. Janice and Ned for providing additional support towards the end of my PhD; Anna, thanks for your Matlab help and I can’t forget all of my volunteers who participated in my studies. I could not have done any of this without you and meeting and getting to know all of you during the data collection phases was the part of my PhD which I always enjoyed. I also need to thank the MRC-ARUK Centre, including Janet, Lisa and Alison, for the funding and support which enabled me to complete this PhD, Hobos Shoes and Two Barefeet Boarding Co. for the shoes I used as control shoes and Vivobarefoot for kindly providing the intervention shoes for my final study. I also need to mention all my friends outside of my PhD life who have been there from the start and continue to offer their support and show interest in my work. Matt, you’ll be glad to hear I’m finally growing up and leaving Uni! As much as you take the mick I know that you’ll always be there if I need your help and you’re truly a great friend. Gracie, your hard work and drive is inspiring and you deserve the very best from life. Ash and Tyler you’re both just great guys with hearts of gold and I have no doubt we’ll be friends for life. Last and by no means least I need to thank my family and April for all the support you have given me throughout the last 4 years. It hasn’t always been plain sailing but you were always there for me to encourage me to keep at it as you said it will all be worth it when I get to the end and look back. I’m glad I listened, I’m proud of the thesis I have produced as a result and I hope I’ve made you proud also. April thanks for putting up with me on a daily basis through it all, your approach to life is an inspiration to me, you always have a smile on your face and always have faith in me and what I can achieve. I couldn’t have done it without you and without doubt the best part of my PhD was meeting you. v Table of Contents List of Figures .............................................................................................................................. i List of Tables ............................................................................................................................. iv List of Abbreviations .................................................................................................................. v List of Publications ................................................................................................................... vii Chapter 2 – Franklin S, Grey M.J, Heneghan N, Bowen L, Li F.X. Barefoot vs. common footwear: A systematic review of the kinematic, kinetic and muscle activity differences during walking, Gait & Posture, 2015, 42(3), 230-239 .......................................................................................... vii Chapter 3 – Franklin S, Grey M.J, Li F.X. Is walking in barefoot-like shoes the same as walking barefoot. A kinematic and kinetic comparison across age. Gait & Posture, 2017; under review ..................................................................................................................................................... vii Chapter 4 – Franklin S, Li F.X, Grey M.J. Modifications in lower leg muscle activation when walking barefoot or in minimalist shoes across different age-groups. Gait & Posture, 2018, 60, 1-5 ................................................................................................................................................ vii Chapter 5 – Franklin S, Li F.X, Grey M.J. Assessing the reliability of a customised device at measuring great toe flexor muscle (gTFM) strength and the importance of its study.; in preparation .................................................................................................................................. vii Chapter 6 – Franklin S, Li F.X, Grey M.J. Increasing Foot Strength Improves Balance in Older Adults.; in preparation ................................................................................................................. vii Chapter 7 – Franklin S, Grey M.J, Li F.X. Does minimalist footwear improve balance and foot strength in older adults?; in preparation .................................................................................... vii Chapter 1 – General Introduction .............................................................................................. 1 1.1 Gait and Balance ..................................................................................................................... 2 1.1.1 The Gait Cycle .................................................................................................................. 2 1.1.2 Balance Mechanisms ....................................................................................................... 7 1.1.2.1 Visual-Vestibular