Asymmetric force applicator attachment for weight stack type exercise machines

摘要

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. As the weights in the stack are being raised, no significant force is generated by the motor and eccentric force control cable. As the weights are being lowered, an amount of additional (i.e. in addition to gravity) eccentric force selected by the user via the keypad is applied to the weight stack by the motor via the eccentric force control cable.