Gait Training Using the Honda Walking Assistive Device® in a Patient Who Underwent Total Hip Arthroplasty: A Single-Subject Study

Background and objectives: The Honda Walking Assistive device^® (HWA) is a light and easy wearable robot device for gait training, which assists patients’ hip flexion and extension movements to guide hip joint movements during gait. However, the safety and feasibility of robot-assisted gait training after total hip arthroplasty (THA) remains unclear. Thus, we aimed to evaluate the safety and feasibility of this gait training intervention using HWA in a patient who underwent THA. Materials and methods: The patient was a 76-year-old woman with right hip osteoarthritis. Gait training using HWA was implemented for 20 sessions in total, five times per week from 1 week to 5 weeks after THA. Self-selected walking speed (SWS), step length (SL), cadence, timed up and go (TUG), range of motion (ROM) of hip extension, and hip abduction and extension torque were measured preoperatively, and at 1 (pre-HWA), 2, 3, 4, 5 (post-HWA), and 10 weeks (follow-up) after THA. The gait patterns at SWS without HWA were measured by using three-dimensional (3D) gait analysis and an integrated electromyogram (iEMG). Results: The patient completed 20 gait training sessions with no adverse event. Hip abduction torque at the operative side, hip extension torque, SWS, SL, and cadence were higher at post-HWA than at pre-HWA. In particular, SWS, TUG, and hip torque were remarkably increased 3 weeks after THA and improved to almost the same levels at follow-up. Maximum hip extension angle and hip ROM during gait were higher at post-HWA than at pre-HWA. Maximum and minimum anterior pelvic tilt angles were lower at post-HWA than at pre-HWA. The iEMG of the gluteus maximus and gluteus medius in the stance phase were lower at post-HWA than preoperatively and at pre-HWA. Conclusions: In this case, the gait training using HWA was safe and feasible, and could be effective for the early improvement of gait ability, hip function, and gait pattern after THA.