MEASURING ELBOW KINEMATICS IN CRICKET BOWLING Theofano Eftaxiopoulou DISSERTATION SUBMITTED IN FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF: DOCTOR OF PHILOSOPHY Departments of Bioengineering and Mechanical Engineering Imperial College London July 2011 MEASURING ELBOW KINEMATICS IN CRICKET BOWLING Acknowledgments First and foremost I would like to sincerely thank my supervisor Professor Anthony Bull for his continuous encouragement and enthusiasm but most of all for his valuable comments and ideas i n every aspect of the thesis . I am also grateful to my co-supervisor Dr John Dear for his guidance, support and advice during this project. I sincerely thank everyone in the Musculoskeletal Biomechanics Group of the department of Bioengineering for being a source of friendship and collaboration over the last three years. However, I am especially grateful to Aliah Shaheen for the patience and skill she showed in teaching me how to use the motion analysis system and the scapula locator and Spyros Masouros for his good advice and encouragement throughout this work. I would like to acknowledge the Marylebone Cricket Club (MCC) and especially Mr. John Stephenson, Mr. Fraser Stewart and Mr. Glen Read for their contribution in sponsoring this project and for allowing me to use their time and facilities whenever required. I would like to express my deepest gratitude to my close friends, Maria Kallivretaki, Giannis Sompolos and Manos Lagopoulos whose support and continuous encouragement, especially during the final stages of this Ph.D. is so appreciated. Thank you. I am forever indebted to my parents Marie and Nicholas and to my brother Harry, without whom this journey would not have been possible. I am thankful to you for supporting and believing in me and allowing me to pursue my passions. To you I dedicate this thesis. 3 MEASURING ELBOW KINEMATICS IN CRICKET BOWLING Ὅτι µπόρεσα ν΄ ἀποχτήσω µία ζωὴ ἀπὸ πράξεις ὁρατὲς γιὰ ὅλους, ἑποµένως νὰ κερδίσω τὴν ἴδια µου διαφάνεια, τὸ χρωστῶ σ΄ ἕνα εἶδος εἰδικοῦ θάρρους ποὺ µοῦ ῾δωκεν ἡ Ποίηση: νὰ γίνοµαι ἄνεµος γιὰ τὸ χαρταετὸ καὶ χαρταετὸς γιὰ τὸν ἄνεµο, ἀκόµη καὶ ὅταν οὐρανὸς δὲν ὑπάρχει. ∆ὲν παίζω µὲ τὰ λόγια. Μιλῶ γιὰ τὴν κίνηση ποὺ ἀνακαλύπτει κανεὶς νὰ σηµειώνεται µέσα στὴ «στιγµή» ὅταν καταφέρει νὰ τὴν ἀνοίξει καὶ νὰ τῆς δώσει διάρκεια. Ὁπόταν, πραγµατικά, καὶ ἡ Θλίψις γίνεται Χάρις καὶ ἡ Χάρις Ἄγγελος·ἡ Εὐτυχία Μοναχὴ καὶ ἡ Μοναχὴ Εὐτυχία. µὲ λευκές, µακριὲς πτυχὲς πάνω ἀπὸ τὸ κενὸ ἕνα κενὸ γεµάτο σταγόνες πουλιῶν, αὖρες βασιλικοῦ καὶ συριγµοὺς ὑπόκωφου Παραδείσου. Ὁ µικρὸς Ναυτίλος Οδυσσέας Ελύτης Whatever I was able to acquire in my life by way of acts visible to all, that is, to win my own transparency, I owe to a kind of special courage Poetry gave me: to be wind for the kite and kite for the wind, even when the sky is missing. I’m not playing with words. I mean the movement you discover being written in an “instant,” when you can open it and make it last. When, in fact, Sorrow becomes Grace and Grace Angel; Joy Alone and Sister Joy with white, long pleats over the void, a void full of bird dew, basil breeze and a hiss of resonant Paradise . The little Mariner Odysseas Elytis (trans: Olga Broumas) 5 MEASURING ELBOW KINEMATICS IN CRICKET BOWLING Abstract In the sport of cricket the objective of the ‘no-ball’ law is to allow no performance advantage through elbow extension during ball delivery. Since the advent of high-speed video photography it has been revealed that some straightening occurs in bowlers who have actions that are traditionally considered in accordance with the law. Measuring the three-dimensional movement of the elbow is vital when assessing bowling legality in cricket. However, the elbow joint is a complex structure with a remarkable range of motion and tracking its movement through skin-based techniques can be highly erroneous due to the thick layer of skin overlying the joint. Within this work, a biomechanical model was mathematically developed and experimentally validated to assess bowling legality in cricket. The new model meets all of the specifications of a measurement method to be used in sports-related biomechanical studies for non-invasive measurement of joint kinematics at high speeds whilst allowing for the subject to move freely within a large volume. The model was compared with existing methods via a series of sensitivity analyses and was found to significantly improve repeatability compared to available elbow measurement techniques particularly in measuring subtle elbow rotations, such as elbow abduction and forearm pronation. In addition this model can be easily implemented within the existing experimental protocol for assessing bowling legality in cricket as proposed by the England and Wales Cricket Board and will be used in future clinical and sport-related studies. 7 MEASURING ELBOW KINEMATICS IN CRICKET BOWLING Contents Acknowledgments .................................................................................................................3 Abstract.................................................................................................................................7 Contents................................................................................................................................9 List of Figures.......................................................................................................................13 List of Tables........................................................................................................................17 List of Abbreviations ............................................................................................................19 Chapter 1 Introduction .................................................................................................... 21 1.1 Motivation ................................................................................................................22 1.2 Main aim and thesis layout.......................................................................................23 Chapter 2 Clinical Biomechanics of the Elbow Joint – Literature Review ............................ 25 2.1 Introduction..............................................................................................................26 2.2 Anatomy and Physiology of the Elbow Joint ............................................................26 2.2.1 Elbow Bones..............................................................................................................27 2.2.1.1 Humerus...........................................................................................................27 2.2.1.2 Ulna..................................................................................................................29 2.2.1.3 Radius...............................................................................................................29 2.2.2 Elbow Joints ..............................................................................................................30 2.2.3 Elbow Movement and Range of Motion ..................................................................31 2.2.3.1 The Carrying Angle...........................................................................................32 2.2.4 Active and Passive Stabilisers of the Elbow Joint .....................................................34 2.3 Elbow Injuries ...........................................................................................................38 2.4 Summary...................................................................................................................39 Chapter 3 The biomechanics of cricket bowling – Literature Review.................................. 41 3.1 Introduction..............................................................................................................42 3.2 Cricket bowling .........................................................................................................42 3.2.1 Fast Bowling..............................................................................................................44 3.2.2 Spin bowling..............................................................................................................45 3.3 The biomechanics of cricket bowling .......................................................................46 3.4 The ‘no ball’ law........................................................................................................48 3.4.1 Definition of a fair delivery.......................................................................................50 3.4.2 Influence of the elbow anatomy on the visual perception of ‘‘throwing’’...............51 3.5 Injuries ......................................................................................................................53 9 MEASURING ELBOW KINEMATICS IN CRICKET BOWLING 3.6 Summary...................................................................................................................56 Chapter 4 Tracking Elbow Movement – Literature Review ................................................ 57 4.1 Introduction..............................................................................................................58 4.2 Elbow Measurement Techniques .............................................................................58 4.2.1 Non-invasive dynamic measuring techniques..........................................................59 4.2.1.1 Motion Tracking Systems.................................................................................59