Posture and Locomotion Coupling: A Target for Rehabilitation Interventions in Persons with Parkinson's Disease

Figure 1

Forward internal model for posture and locomotion coupling during the initiation of gait. To initiate stepping locomotion, posture and locomotion networks are activated in parallel to generate motor commands where the posture network acts on the stepping controller. This motor output modifies the body center of mass-base of support (COM-BOS) relationship. With external posture assistance (e.g., mechanical or sensory simulation of single stance limb loading) that enhances weight transfer to the single stance limb, an efferent copy of the motor commands and sensory information about the actual state of the body can be used by the CNS to modify the two commands in advance based on an internal representation of the body and external environment (forward model). Online sensory information can also modulate posture and locomotion via external feedback.