In this paper we present a novel approach in human/robot collaboration, where the robot controls not only its arm but also the human's by means of functional electrical stimulation (FES). The task is described by using the cooperative dual task-space approach, providing a considerable degree of invariance with respect to the morphology of the agents involved. Experimental results in a "ball in the hoop" task using healthy blindfolded subjects show the validity of the approach and encourages further experiments with impaired subjects, for instance hemiplegic or quadriplegic patients.