Analysis of the underlying principles of the following types of therapeutic exercise: stretching, strengthening; active assistive; active; resistive, using manual resistance pulleys, weights, hydraulics, elastics, robotics, and mechanical or electromechanical devices: neuromuscular relation, inhibition and facilitation; neuromuscular reeducation; motor training or retraining; developmental; activities; breathing exercises, including ventilatory muscle training; aerobics endurance activities, using cycles, treadmills, steppers, pools, manual resistance, pulleys, weights, hydraulics, elastics, robotics, and mechanical or electromechanical devised; aquatics exercises; and conditioning and reconditioning.