Effects of Timed Frontal Plane Pelvic Moments During Overground Walking With a Mobile TPAD System

Robotic gait trainingmay improve overground ambulation for individuals with poor control over pelvic motion. However, there is a need for an overground gait training robotic device that allows full control of pelvic movement and synchronizes applied forces to the user's gait. This work evaluates an overground robotic gait trainer that applies synchronized forces on the user's pelvis, the mobile Tethered Pelvic Assist Device. To illustrate one possible control scheme, we apply assistive frontal plane pelvic moments synchronized with the user's continuous gait in real-time. Ten healthy adults walked with the robotic device, with and without frontal planemoments. The frontal plane moments corresponded to 10% of the user's body weight with a moment arm of half their pelvic width. The frontal plane moments significantly increased the range of frontal plane pelvic angles from 2.6 degrees to 9.9 degrees and the sagittal and transverse planes from 4.6 degrees to 10.1 degrees and 3.0 degrees to 8.3 degrees, respectively. The frontal plane moments also significantly increased the activation of the left gluteus medius muscle, which assists in regulating pelvic obliquity. The right gluteus medius muscle activation did not significantly differ when frontal plane moments were applied. This work highlights the ability of themobile Tethered Pelvic Assist Device to apply a continuous pelvic moment that is synchronized with the user's gait cycle. This capability could change how overgroundrobotic gait training strategies are designed and applied. The potential for gait training interventions that target gait deficits ormuscleweakness can now be explored with the mobile Tethered Pelvic Assist Device.