[临床医学]BasicKineticConcepts.pdf

Basic Kinetic Concepts Course Content I. Introduction to the Course II. Biomechanical Concepts Related to Human Movement III. Anatomical Concepts Related to Human Movement IV. Functional Anatomy of Selected Joint Biomechanical Concepts A. Basic Kinematic Concepts B. Basic Kinetic Concepts What is kinetics? The study of forces tending to cause or result from motion. Can identify and alter forces to change motion for desirable results. Basic Kinetic Concepts 1. Force 2. Torque 3. Free Body Diagrams( 自由体图) Basic Kinetic Concepts 1. Force 2. Torque 3. Free Body Diagrams Force A push or pull Vector quantity with 4 characteristics Magnitude Direction Point of application Line of force The interaction of an object with its surroundings For a force to cause acceleration: Must overcome opposing forces (net force) Must overcome inertia (mass) Even if acceleration does not occur, deformation of the object will occur. Common Forces Weight Reaction forces GRF,Ground reaction forces Friction JRF,joint reaction forces Muscle force Elastic force Intraabdominal pressure Inertial force Fluid force Basic Kinetic Concepts 1. Force 2. Torque 3. Free Body Diagrams Torque AKA moment of force, or moment The ability of a force to create rotation  Fd moment arm - perpendicular distance from the line of force to the axis of rotation Must have a moment arm (be an eccentric force) For a torque to cause angular acceleration: Must overcome opposing torques (net torque) Must overcome moment of inertia (mass, length of the rotating body) Which way will the door turn? FC = 200 N dC = .05 m FB = 100 N