The conceptual design of a new sitting-type lower-limb rehabilitation robot along with simplified motion control for its passive range of motion therapies is put forth here. The suggested system’s design is demonstrated and verified using computer-based numerical simulations. For this, the desired motion trajectory is generated with the help of a clinically obtained gait data-set. The robustness of the proposed simplified motion control scheme is verified with the variation of the physical parameters of the patients’ limb. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020.