Force measurement and ankle motion of the forward skating and crossovers with a standard hockey skate and a modified hockey skate Xavier Robert-Lachaîne Department of Kinesiology and Physical Education McGill University, Montreal Quebec, Canada August 2010 A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Masters of Science © Xavier Robert-Lachaîne, 2010 STATEMENT OF ORIGINALITY All material presented in this thesis contains original work completed by the author with the help of McGill’s biomechanics laboratory, except external contributions via references where noted. It is the belief of the author that the material presented contributes to analysis of the kinetics and kinematics of ice hockey skating, as well providing insights into the impact of hockey skate design modifications on skating performance. II ACKNOWLEDGEMENTS I would like to thank Dr. René Turcotte, my supervisor, for giving me direction in the writing of this thesis. His thoughtful advices were based on his experience and answered most of my questions. He was always available to discuss about any aspect of the project. René made sure to give structure to the thesis and assisted me with writing in English, which is my second language. It was fun to work with René who often relaxes the working environment with hockey comments. The contribution of David Pearsall was also considerate. He always put the biomechanical perspective in thought. The technological aspect of the project was evolving a step further with his notable interventions. David insured to get to maximum out of my potential by discussing about the improvement of the methodology and setting deadlines to accomplish specified objectives. The presence of Phil Dixon in the laboratory was an immense source of support. He was often the first person to assist me with any kind of problems during my project. His competence in various fields made him a perfect teacher. Without your help Phil, I would still be in the laboratory writing Matlab functions. Thanks! The help of Yannick Michaud-Paquette was always appreciated. He was ready to assist me whenever he could. Yan made lunchtime entertaining with the various TV shows that brought people together. III Sylvain Gaudet gave me a good support during the construction of the lever and the subsequent calibration. He showed great interest in the project and helped during the data collection. I would also like to thank Adrian De Vincenzo who assisted me for testing during the pilot studies. Ryan was a great help; his expertise in the electronics gave more professionalism to my project. Thanks to Jonathan, Ashley, Zubair, Antoine and Rob for their help with the instrumentation of the skates, testing or data collection. Thanks to Pat and Joe Leamy for providing me with ice times for my data collection. Thanks to McGill Redmen hockey players and other hockey players who freely participated in this study and gave interest throughout. The partnership with Bauer hockey was important for this thesis; they provided the laboratory with hockey equipment, especially the DROM skates. Chris Langevin and Ken Covo also gave depth to the project. Finally, the support of my family was constant throughout my graduate studies. Specifically, my father Serge who gave me the desire to pursue my interests in life and my wife Pierina who is always by my side whatever happens. Thanks to my newly born Selena for all the love you bring. IV CONTRIBUTION OF AUTHORS The following thesis will be submitted for a publication. The paper will be co-authored by Dr. René Turcotte and Dr. David Pearsall; I will be the primary author. I was responsible of conducting the research and writing the thesis. I have instrumented and calibrated the skates, collected the data, processed the data and made a statistical analysis. I was writing the chapters involving introduction, review of literature, methods, results and discussion. Dr. Turcotte was providing comments throughout the writing of the thesis and insured a coherent English. He helped defining the rationale of the study and the experimental design and suggested articles to discuss. Dr. Pearsall was influential in the development of the methods, he also made comments on the chapters and helped in the structure of the ideas. V ABSTRACT Dynamic forces were measured during skating directly on-ice using a Bauer One95 and a second One95 with a modified tendon guard and eyelet configuration (DROM). The intent was to determine if mechanical differences exist in push-off force and ankle kinematics between the two skates. The right skate of each type was instrumented with a calibrated force transducer system to measure medial-lateral and vertical forces during ice skating. In addition, a goniometer was installed about the ankle to measure kinematics during skating. The ten subjects executed three skills: forward skating and forward crossovers in both directions. The DROM skate demonstrated significant gains in plantarflexion and net plantar-dorsiflexion ROM. In general this was not reflected in greater kinetic output except for greater medial-lateral forces. Total peak force occurred later during plantarflexion, suggesting that the increased ROM resulted in a more prolonged force generation during a given skating stride. The 14 to 20% increases in work and power output while wearing the DROM skates did not translate into improved times for these skating tasks. These apparently contradictory findings may well be attributed to lack of player familiarity with the modified skate’s greater ankle mobility. Hence, to determine the DROM skate’s true performance benefits, a longitudinal study of a cohort of players training with the DROM skate is required. VI ABRÉGÉ Les forces de patinage ont été mesurées directement sur glace avec un Bauer One95 (Régulier) et un second One95 qui détenait un protecteur du tendon d’Achille modifié et une configuration différente des œillets pour lacets (DROM). Le but était de déterminer si des différences mécaniques existent dans la force de propulsion et la cinématique de la cheville entre les deux modèles. Le patin droit était instrumenté d’un système calibré d’estimation de la force qui permettait la mesure dynamique des forces durant le patinage. De plus, un goniomètre était installé autour de la cheville pour mesurer la cinématique durant le patinage. Les dix sujets accomplissaient le patinage avant et le croisé-avant dans les deux directions. Le patin DROM démontrait des gains significatifs en flexion plantaire et amplitude de mouvement frontale. En général, ces résultats ne se sont pas reflétés en bénéfices cinétiques, à l’exception des forces médio-latérales. La force totale maximale était délayée avec le DROM, suggérant une production de force prolongée qui résultait de l’amplitude de mouvement supplémentaire. Les augmentations de 14 à 20% en travail et puissance avec le DROM ne se sont pas traduites en amélioration de vitesse. Ces trouvailles apparemment contradictoires pourraient être attribuables au manque d’accoutumance des joueurs avec le patin modifié qui procure une mobilité supérieure à la cheville. Afin de déterminer le potentiel optimal du DROM sur la performance, une étude longitudinale avec un groupe de joueurs s’entraînant avec le DROM est nécessaire. VII TABLE OF CONTENTS STATEMENT OF ORIGINALITY .......................................... II ACKNOWLEDGEMENTS .................................................. III CONTRIBUTION OF AUTHORS ..........................................V ABSTRACT...................................................................VI ABRÉGÉ...................................................................... VII TABLE OF CONTENTS .................................................. VIII LIST OF FIGURES .......................................................... XI LIST OF TABLES ......................................................... XIV CHAPTER 1 – INTRODUCTION ..........................................1 1.1 THESIS OUTLINE .......................................................... 1 1.2 NOMENCLATURE, OPERATIONAL DEFINITIONS AND ABBREVIATIONS ................................................................ 1 1.3 RATIONALE ................................................................. 6 1.4 PURPOSE ................................................................... 12 1.5 HYPOTHESES ............................................................. 12 1.6 LIMITATIONS ............................................................. 13 1.7 DELIMITATIONS.......................................................... 13 CHAPTER 2 – REVIEW OF LITERATURE ............................ 15 2.1 HISTORY OF HOCKEY .................................................. 15 2.1.1 Evolution of the skate ..............................................................15 2.2 HOCKEY SKILLS CLASSIFICATION ................................. 16 2.2.1 Internal factors affecting performance.....................................17 2.2.2 External factors affecting performance....................................19 2.2.2.1 Air friction....................................................................................19 2.2.2.2 Ice friction....................................................................................20 VIII 2.2.2.3 Skate properties ..........................................................................22 2.2.2.3.1 Boot stiffness.......................................................................22 2.2.2.3.2 Range of motion (ROM) ........................................................23