= describes & predicts conditions of rest or motion of biological systems under the action of forces. = mechanical aspects of human movement & role of force, time, dist. = study of forces and their effects on living systems. Obtaining 3d model using a vicon: re ective markers (at least 3 per segment) attached to skin, solids of revolutions created based on location of skin markers, bone models added to re ect human anatomy. Devices to measure:: time = stop watches, stroboscopes, rxn timers, phototimers, video recording, space = tape measure, micrometers, anthropometer, gps, photography, cinematography, sonic devices. Coordinate systems: 2d => polar (x, ) & cartesian/rectangular (x, y, 3d => cartesian (x, y, z), cylindrical (x, , z), spherical, direction cosines. Laws of rigid body mechanics : parallelogram law (cummulative law for vector addition), universal law of gravitation, a) all bodies attracted to all other bodies w a force, force = directly proportional to product of their masses.