Robots　are　increasingly　being　used　in　rehabilitation　to　assist　patients　with　physical　disabilities,　particularly　the　knee　joint.　Physiotherapists　often　practice　the　patient’s　leg　around　the　knee　joint　to　strengthen　the　muscles.　However,　Continuous　Passive　Motion　(CPM)　devices　face　challenges　such　as　lack　of　feedback　and　resistance.　This　thesis　aims　to　address　these　issues　by　using　admittance　and　impedance　concepts　to　control　the　robot’s　flexible　behavior　against　individual　foot　forces.　The　research　uses　a　combination　of　backstepping　and　admittance　algorithms,　Model　Reference　Adaptive　Control　(MRAC),　Sliding-Backstepping　and　Admittance　Control　to　create　a　soft　interactive　patient-robot　interaction.　The　device　is　designed　for　both　left　and　right　legs.　©　IMechE　2024.