Maximal motor unit discharge rates of the medial and lateral gastrocnemeii of young males

................................................................................................................................................ i TABLE OF CONTENTS ............................................................................................................................ v LIST OF ABBREVIATIONS ................................................................................................................... vii LIST OF TABLES ................................................................................................................................... viii LIST OF FIGURES ................................................................................................................................... ix LIST OF APPENDICES ............................................................................................................................. x CHAPTER 1: INTRODUCTION ............................................................................................................... 1 1.1 TRICEPS SURAE ........................................................................................................................ 1 1.1.1 General .................................................................................................................................. 1 1.1.2 Muscle Architecture and Length ........................................................................................... 2 1.1.3 Muscle Volume ..................................................................................................................... 4 1.1.4 Strength and Twitch Contractile Properties .......................................................................... 5 1.2 MOTOR UNIT ............................................................................................................................. 9 1.2.1 History and Definition .......................................................................................................... 9 1.2.2 Maximal discharge rates ..................................................................................................... 10 1.2.3 Triceps Surae and Length-Dependent Motor Unit Properties ............................................ 12 1.3 PURPOSE & HYPOTHESIS ..................................................................................................... 14 CHAPTER 2: METHODS ........................................................................................................................ 16 2.1 PARTICIPANTS ........................................................................................................................ 16 2.2 EXPERIMENTAL SETUP ........................................................................................................ 16 2.3 RECORDING............................................................................................................................. 17 2.3.1 Surface EMG ...................................................................................................................... 17 2.3.2 Intramuscular EMG ............................................................................................................ 18 2.4 PROTOCOL ............................................................................................................................... 19 2.5 ANALYSIS ................................................................................................................................ 20 2.6 STATISTICS .............................................................................................................................. 23 CHAPTER 3: RESULTS .......................................................................................................................... 24 3.1 SURFACE ELECTROMYOGRAPHY ..................................................................................... 24 3.2 MVC TORQUE & TWITCH CONTRACTILE PROPERTIES................................................ 24 3.3 MOTOR UNIT DATA ............................................................................................................... 24 3.3.1 Motor Unit Trains ............................................................................................................... 24