Excessive loading of the medial compartment of the knee and functional instability in the off-axis planes (frontal and transverse planes) are related to the development, progression, and severity of knee osteoarthritis (KOA). Gait modification strategies such as walking with a modified foot progression angle (FPA) and wider step-width can reduce peak knee adduction moment (pKAM), a surrogate measure of medial knee loading. Specifically, subject-specific FPAs are shown to be more effective in lowering KAM than a generalized FPA. However, detecting the minimum alteration in the kinematic gait parameters that reduce pKAM by a specific amount without causing an unnatural walking pattern has yet to be investigated. Another strategy to reduce pKAM is the electrically induced contraction of the primary knee muscles, such as the long head of the biceps femoris and lateral gastrocnemius, which provide resistance to pKAM. However, studies are scarce on the immediate effect of the enhanced activation of these muscles on pKAM during functional tasks such as elliptical stepping, an exercise recommended for KOA rehabilitation. Firstly, this work explored the feasibility of determining the subject-specific FPA and step-width during the footplates' motorized rotation and linear transition of a robotic elliptical stepping system. Study findings demonstrated a linear relationship between pKAM and FPA and pKAM and step-width during stepping. Using the characteristics of these relationships, we could estimate the minimum change in the FPA and step-width to induce a desired pKAM reduction. Secondly, this work explored the effect of functional electrical stimulation (FES) of the lateral knee muscles on pKAM during the stepping task. Participants reduced their pKAM with FES of lateral gastrocnemius and biceps femoris, which indicated the feasibility of using combined FES and elliptical stepping for pKAM reduction. Thirdly, the last study used a subject-specific training program using the robotic elliptical stepping system to assess the training’s effect on pKAM, functional instability, and clinical outcome measures in participants with KOA. Participants reduced their pKAM and functional instability and improved their stepping speed, gait velocity, and symptoms. These findings demonstrate the feasibility of subject-specific training with the robotic elliptical stepping system for KOA rehabilitation.