Abstract: The disclosure provides gait modification or treatment apparatus, systems and methods that are appropriate for everyday life, have a significant mechanical effect, and provide a mechanism for tracking the compliance and performance of the patient to allow for individualized management of a gait modification prescription or treatment plan or sequence. Gait modification/treatment apparatus, systems and methods utilizing substantially rectilinear projections in the hindfoot and the forefoot are disclosed. Gait modification/treatment apparatus, systems and methods utilizing a projection that defines an engagement surface extending from the hindfoot to the forefoot are also disclosed. Gait modification/treatment apparatus, systems and methods utilizing a non-linear guide rail extending from the hindfoot to the forefoot are also disclosed.