With　the　popularization　of　biomechanical　simulation　technology,　aiming　at　the　rehabilitation　of　ankle　joint　injury,　we　imported　simplified　model　of　proposed　2-UPS/RR　(two　identical　unconstraint　kinematic　branches　with　a　universal–prismatic–spherical　(UPS)　structure　and　two　rotating　pair　(R))　ankle　rehabilitation　robot　into　AnyBody　Modeling　System.　Therefore,　a　human–machine　model　was　established　using　the　HILL-type　muscle　model　and　muscle　recruitment　criteria.　This　paper　investigated　the　effects　of　rehabilitation　trajectories　on　biomechanical　response　during　rehabilitation.　Additionally,　three　main　lower　limb　muscles　(soleus,　peroneal　brevis,　and　extensor　digitorum　longus)　were　examined　under　different　rehabilitation　trajectories　(plantar　dorsiflexion,　varus　or　valgus,　and　compound　movement)　in　the　present　study.　Based　on　the　biomechanical　response　of　lower　limbs,　the　results　showed　that　different　muscles　had　different　sensitivities　to　the　change　of　rehabilitation　trajectories.　The　correlation　coefficient　between　joint　force　and　plantar　dorsiflexion　angle　reached　0.99　(P　©　2022,　International　Federation　for　Medical　and　Biological　Engineering.