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Hasegawa M.1, Miyazaki M.2, Yokota K.1, Nakahara Y.1, Vitale K.3, Haga N.1
1University of Tokyo Hospital, Tokyo, Japan, 2Teikyo Heisei University, Tokyo, Japan, 3University of California, San Diego, United States
Background: The hybrid assistive limb (HAL) is a newly developed robotic device assisting lower limb movements with the wearer's intention via exoskeleton-powered motion based on the user's bioelectric signals. It is mainly used in Japan, Germany and Sweden for lower limb disabilities affected by neurological and musculoskeletal diseases. However, there is little evidence regarding its effectiveness.
Purpose: To systematically review current literature evaluating the effectiveness of HAL during physical therapy in lower limb disability.
Methods: A systematic review was performed following PRISMA guidelines and was registered in PROSPERO database. Inclusion criteria were studies written in English or Japanese on HAL with lower extremity neurological or musculoskeletal pathology through August 31st 2016. MEDLINE, CINAHL, Web of Science, and Cochrane Library were used for English; Medical Online, Ichushi, and CiiNi were used for Japanese; additionally, relevant studies were manually searched.
Results: 617 potential studies were identified; 15 English and 6 Japanese studies met eligibility criteria. Two reviewers extracted study data and outcomes. There was 1 randomized controlled trial (RCT), 4 non-RCTs, 13 individual studies and 3 cohort studies. A meta-analysis could not be completed due to insufficient clinical and methodological homogeneity among studies. The most frequent condition treated was stroke, in 16 studies (8 acute, 5 sub-acute, 3 chronic). Two studies were for chronic spinal cord injury (SCI), 1 for knee osteoarthritis (OA), and 3 for mixed populations. Subject numbers varied from 7 to 53 patients. Most (20 studies) used HAL for gait retraining; 1 assessed sit-to-stand transfer training. Physical therapy visits with HAL ranged from 1-time only to 60 sessions. Only 9 studies had formal HAL training protocols; 2 German (5 sessions/week x 12 weeks) and 2 Japanese studies (2 sessions/week x 8 weeks) were standardized. The most frequent outcomes were gait function parameters (e.g. gait speed) (12 studies), Activities of Daily Living (ADL) (7 studies), balance function (6 studies), and Brunnstrom staging (5 studies). Other outcomes, including sit-to-stand transfers, cortical excitability, length of hospital stay, Borg scale, and safety of HAL during physical therapy were assessed once each. Overall, 10 studies showed gait improvements and 2 showed improvements in ADL status, balance, and Functional Ambulatory Capacity. Only two studies did not show significant gait differences with or without HAL.
Conclusion(s): HAL has mainly been used for stroke but also in treatment of SCI, knee OA and other diseases. Most studies investigated its potential improvements in gait function, but use of HAL in physical therapy may also improve balance and independence with ADLs.
Our systematic review identified previous studies examining the effectiveness of HAL in physical therapy for lower limb disability. Currently there is a lack of high-quality studies and a paucity of RCTs. Its true efficacy remains unknown but may improve gait, balance, and ADL status based on available literature.
Implications: Larger scale higher quality studies, with similar patient characteristics and a standardized rehabilitation protocol, are needed to adequately perform a review and identify the effectiveness of physical therapy in lower limb disability by utilizing HAL.
Funding acknowledgements: There is no funding in this study.
Topic: Professional practice: other
Ethics approval: This study does not require ethics approval.
All authors, affiliations and abstracts have been published as submitted.
