Apparatus and associated methods relate to a knee-position control system having a knee engagement pad, a lower-leg control member and an upper-leg control member, the knee engagement pad configured to naturally position a user's knee in response to movement of a foot-rest of a natural-gait therapy system. In an illustrative embodiment, the upper-leg control member may pivot about a point substantially axially coincident with a user's hip. In some embodiments, the upper-leg control member may be pivotally coupled to the lower-leg control member at a pivot point substantially axially coincident with a user's knee. The lower-leg control member may be pivotably coupled to the foot rest at a pivot point substantially axially coincident with a user's ankle. The knee-position control system may advantageously position a user's knee in a natural position relative to both the user's ankle and the user's hip, in response to movement of the user's foot.