Abstract: A device and methods for performing a closed-chain exercise for the lower extremities of a human subject and, in particular, the legs, using stimulation. The device may include a sled for receiving the subject and for translating to and fro between a first, lower position in which the legs are at least partially bent and a second, higher position in which the legs are less bent than in the first position. A stimulator is provided for facilitating the performance of the closed-chain leg exercise by the subject to move the sled between the first and second positions, either by way of electrical signals provided directly to the applicable muscles or by way of sensory (e.g., visual) stimulation, with or without electro-muscular stimulation. In another aspect, adaptive feed-forward control may also be used to enhance the exercise regimen performed using the device.