Abstract: An exercise and rehabilitation system includes a patient positioning system, a dynamometer, an electronics module, a computer and a communications module. The electronics module includes a servo-amplifier and a controller and the controller receives torque and position data from the dynamometer, computes the control signal for the servo-amplifier, receives high-level control settings from the computer and communicates torque and position data to the computer. The communications module communicates with the electronics module, and the computer.

Abstract: An attachment for a weight stack type exercise machine to pull the weight stack down while it is being lowered, (or to pull on a weight stack lifting means so as to add to the force applied to the lifting means by the weight stack) so that the eccentric exercise force required to lower the stack is greater than the concentric exercise force required to raise it. Such asymmetric exercise forces more closely match muscle strengths, which are normally greater for eccentric exercise than for concentric exercise. The attachment has an electric motor and a control unit including a keypad, a display and a microcontroller. The motor is coupled to the weight stack by an eccentric force control cable or a toothed belt or alternatively is operatively connected so as to apply additional force to the lifting arrangement. The keypad allows the user to select the amount of force added during the eccentric phase of exercise, when the weight stack is moving down.

Abstract: An attachment for a weight stack type exercise machine to pull the weight stack down while it is being lowered, so that the eccentric exercise force required to lower the stack is greater than the concentric exercise force required to raise it. Such asymmetric exercise forces more closely match muscle strengths, which are normally greater for eccentric exercise than for concentric exercise. The attachment has an electric motor and a control unit including a keypad, a display and a microcontroller. The motor is coupled to the weight stack by an eccentric force control cable. The keypad allows the user to select the amount of force added during the eccentric phase of exercise, when the weight stack is moving down and part of a lifting cable connected to a handle or engageable member on the weight stack type machine is moving in. A sensor enables the controller to determine whether the weight stack is moving up or down.

Abstract: A motor-driven treadmill includes a stationary ultrasonic range finder which continuously measures the distance to the torso of a person walking or running on the moving tread of the treadmill. When the person approaches too closely to the front of the treadmill, the treadmill speed and/or the treadmill slope are increased; and when the person retreats too far away from the front of the treadmill, the treadmill speed and/or the treadmill slope are decreased. The response of the treadmill speed and/or slope control system may be improved by making the controller responsive to the rate of change of the distance between the person using the treadmill and the front of the treadmill, so as to provide anticipation of the distances which will be traversed by the user of the treadmill.