Early Postoperative Rehabilitation Using the Hybrid Assistive Limb (HAL) Lumbar Type in Patients With Hip Fracture: A Pilot Study

Abstract

OBJECTIVE: To extend life expectancy after surgery, patients with hip fractures need to improve their mobility quickly through postoperative rehabilitation. Voluntary hip joint motion supported by the hybrid assistive limb (HAL) lumbar type, an exoskeleton robot suit characterized by its ability to detect the wearer's intentions through the bioelectrical signals and assist hip extension motions at an optimal timing, may be effective to improve mobility in patients with hip joint dysfunction after surgery. We aimed to introduce rehabilitation using the HAL lumbar type in the early period after hip fracture surgery. METHODS: Patients who underwent internal fixation for hip fracture at a single institution were prospectively enrolled. They received early postoperative rehabilitation (forward and backward bending of the lumbar spine, pelvic tilt forward and backward, standing up, and squatting) using the HAL lumbar type (six times a week for 15 min per session). Five-times-sit-to-stand (FTSS) and timed-up-and-go (TUG) tests were conducted at baseline before HAL rehabilitation (pre-HAL) and after the HAL rehabilitation (post-HAL) intervention. RESULTS: We enrolled 14 patients (one man, 13 women) in this study. There were no adverse events, and all patients were able to complete the entire rehabilitation program. Post-HAL FTSS showed significant improvement compared with pre-HAL and had a large effect size of 1.81 (95% CI = 0.93 to 2.66) and sufficient power. CONCLUSIONS: Robotic rehabilitation with HAL lumbar type could be introduced without adverse events, even in the early postoperative period following surgery for hip fracture. Further study is needed to develop an appropriate rehabilitation protocol using the HAL lumbar type.