Factors Predicting the Effects of Hybrid Assistive Limb Robot Suit during the Acute Phase of Central Nervous System Injury

To improve the activities of daily living of patients with injury to the central nervous system, physical therapy starting from the acute phase of the injury is important. Recently, the efficacy of physical therapy using a hybrid assistive limb (HAL) robot suit was reported. However, individual differences exist in the effects of HAL. We investigated factors predicting the effects of HAL in 15 patients at our institution with central nervous system injury, primarily due to stroke, who underwent training using HAL during the acute phase. Patients were classified as either "with HAL suitability" or "without HAL suitability" based on scores from 10-m walking speed, gait, satisfaction, and pain. In both groups, Brunnstrom stage before HAL intervention, Fugl-Meyer assessment (FMA), stroke impairment assessment set (SIAS), and functional independence measure (FIM) were evaluated. Although motor function items did not differ significantly, FIM cognitive function items (P = 0.036), visuospatial perception items on SIAS (P = 0.0277), and pain items on SIAS (P = 0.0122) differed significantly between groups. These results indicated that training using HAL does not involve pain in patients with central nervous system injury during the acute phase, and exhibits positive effects in patients without pain and with high communication ability and visuospatial perception function. When conducting HAL intervention, incorporating functional assessment scores (FIM and SIAS), including peripheral items, may be useful to predict the suitability of HAL.