A method of rehabilitating a person using a person lift device, includes the steps of: calculating a first amount of assistance provided by the person lift device to assist a person in moving between a first position and a second position at a first time; comparing the first amount of assistance to a previously determined amount of assistance; and providing a second amount of assistance as a function of the difference between the first amount of assistance and the previous amount of assistance to assist a person in moving between the first position and the second position at a second time.