Biomechanics of the Human Body

Forces.- Objectives.- Force concept.- Representation of forces: diagram of forces.- Resultant force.- Sum of vectors.- Polygon rule.- Parallelogram rule.- Components method.- Trigonometric method.- Newton's law.- First law.- Second law.- Third law.- Some specific forces.- Force of gravity.- Muscle force.- Contact force, reaction and normal force.- Frictional force.- Pressure.- Torques.- Objectives:.- Concept: Torque produced by a force.- Binary Torque due to two or more non parallel forces.- Rotational equilibrium.- Center of gravity.- Objectives:.- Weight and center of gravity.- Practical method for determining the center of gravity.- Analytical method for determining the center of gravity.- Equilibrium: stable, unstable and neutral.- Movement of the center of gravity.- Rotations.- Objectives:.- Moments of inertia.- Moment of inertia of extended bodies with regular geometry.- Radius of gyration.- Parallel axis theorem.- Moment of inertia of the human body.- Angular momentum and its conservation.- Variation of angular momentum.- Simple machines.- Objectives:.- Work done by a force.- Levers.- First class levers.- Second class levers.- Third class levers.- Levers in the human body.- Moving body.- Articulations and joints.- Muscle and levers.- Identification of levers.- Pulleys.- Combination of pulleys.- Traction systems.- Inclined plane.- Muscles.- Objectives.- Equilibrium conditions of a rigid body.- System of parallel forces.- System of non parallel forces.- Forces on the hip.- Forces on the spinal column.- Forces on the spinal column with incorrect posture.- Forces on the spinal column with correct posture.- Bones.- Objectives.- Skeleton and bones.- Composition of bones.- Mechanical properties of solids.- Tensile and compressive forces.- Elastic modulus.- Young's modulus.- Shear modulus.- Mechanical properties of bones.- Pressure or stress on intravertebral discs.- Pressure on vertebra.- Shear stress in lumbo-sacral disc.- Breaking of bones in collisions.- Easy laboratory exercises.- Introduction.- Significant figures and precision.- Activity 1: construction and calibration of a dynamometer using a rubber band.- Activity 2: conditions for static equilibrium with relation to translation.- Activity 3: experiment with torque, using rubber band dynamometer.- Activity 4: center of gravity - construction of a very stable system .- Activity 5: construction of a system to analyze moment of inertia and conservation of angular momentum.- Activity 6: construction and analysis of different classes of levers.- Activity 7: construction and analysis of inclined plane.- Activity 8: rubber band dynamometers in series and parallel, to simulate muscles.- Activity 9: determination of tensile strength of a rubber band.