How Biomechanics Can Improve Sports Performance：如何提高运动生物力学性能.pptVIP

How Biomechanics Can measure Performance D. Gordon E. Robertson, PhD Fellow, Canadian Society for Biomechanics Emeritus Professor, School of Human Kinetics, University of Ottawa, Ottawa, Canada What is Biomechanics? Study of forces and their effects on living bodies Types of forces External forces ground reaction forces forces applied to other objects or persons fluid forces (swimming, air resistance) impact forces Internal forces muscle forces (strength and power) forces in bones, ligaments, cartilage Types of analyses Temporal (times, timing) Kinematic (positions, motion) Kinetic (forces, moments of force) Direct Indirect Electromyographic (muscle activation) Temporal Analyses Quantifies durations of performances in whole (race times) or in part (split times, stride times, stroke rates, etc.) Instruments include: stop watches, electronic timers timing gates frame-by-frame video analysis Easy to do but not very illuminating Necessary to enable kinematic studies Example: Electronic timing Donovan Bailey sets world record (9.835) despite slowest reaction time (0.174) of finalists Kinematics Position, velocity (speed) acceleration Angular position, velocity acceleration Distance travelled tape measures, electronic sensors, trundle wheel Linear displacement point-to-point linear distance and direction Angular displacement changes in joint angular orientations from point-to-point, 3D angles are order specific Kinematics Instrumentation includes: tape measures, electrogoniometers speed guns, accelerometers motion capture from video or other imaging devices (cinefilm, TV, infrared, ultrasonic, etc.) GPS, gyroscopes, wireless sensors Kinematics Cheap to very expensive Cheap yields low information e.g., stride length, range of motion, distance jumped or speed of object thrown or batted Expensive yields over-abundance of data e.g., marker trajectories and their kinematics, segment, joint, and total body linear and angular kinematics, in 1, 2, or 3 dimensions essential fo