Power assist robots are usually used for rehabilitation. This paper brings a novelty in power-assist applications and presents a model for manipulating objects. However, power-assist devices for object manipulation can be human-friendly if and only if human characteristics for power-assisted object manipulation are analyzed, compared them with that for manual manipulation and the findings as a whole are included in the control design. However, such biomimetic approach to power assist control design is absent. This paper deals with the development of two independent systems-one for lifting/lowering objects manually and the other for lifting/lowering objects with power-assist. We analyzed human characteristics such as weight perception, load forces, motions etc. for lifting/lowering objects manually and with power-assist and compared them with each other, and thus identified several control parameters. Then we proposed to use the control parameters to determine appropriate control methods and strategies for power assist robots for handling heavy objects in industries that may improve human-robot interactions.