Background and objectives: The Honda Walking Assistive device® (HWA) is a light and easywearable robot device for gait training, which assists patients' hip flexion and extension movementsto guide hip joint movements during gait. However, the safety and feasibility of robot-assisted gaittraining after total hip arthroplasty (THA) remains unclear. Thus, we aimed to evaluate the safetyand 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. Gaittraining using HWA was implemented for 20 sessions in total, five times per week from 1 week to5 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 weremeasured preoperatively, and at 1 (pre-HWA), 2, 3, 4, 5 (post-HWA), and 10 weeks (follow-up) afterTHA. The gait patterns at SWS without HWA were measured by using three-dimensional (3D) gaitanalysis and an integrated electromyogram (iEMG).
Results: The patient completed 20 gait trainingsessions 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, andhip torque were remarkably increased 3 weeks after THA and improved to almost the same levelsat follow-up. Maximum hip extension angle and hip ROM during gait were higher at post-HWAthan at pre-HWA. Maximum and minimum anterior pelvic tilt angles were lower at post-HWA thanat pre-HWA. The iEMG of the gluteus maximus and gluteus medius in the stance phase were lowerat post-HWA than preoperatively and at pre-HWA.
Conclusions: In this case, the gait training usingHWA was safe and feasible, and could be effective for the early improvement of gait ability, hipfunction, and gait pattern after THA.
Keywords: The Honda Walking Assistive Device®; gait training; total hip arthroplasty.