Voluntary driven exoskeleton as a new tool for rehabilitation in chronic spinal cord injury: a pilot study.
BACKGROUND
Treadmill training after traumatic spinal cord injury (SCI) has become an established therapy to improve walking capabilities. The hybrid assistive limb (HAL) exoskeleton has been developed to support motor function and is tailored to the patients' voluntary drive.


OBJECTIVE
To determine whether locomotor training with the exoskeleton HAL is safe and can increase functional mobility in chronic paraplegic patients after SCI.


METHODS
A single case experimental A-B (pre-post) design study by repeated assessments of the same patients. The subjects performed 90 days (five times per week) of HAL exoskeleton body weight supported treadmill training with variable gait speed and body weight support.


METHODS
Eight patients with chronic SCI classified by the American Spinal Injury Association (ASIA) Impairment Scale (AIS) consisting of ASIA A (zones of partial preservation [ZPP] L3-S1), n=4; ASIA B (with motor ZPP L3-S1), n=1; and ASIA C/D, n=3, who received full rehabilitation in the acute and subacute phases of SCI.


METHODS
Functional measures included treadmill-associated walking distance, speed, and time, with additional analysis of functional improvements using the 10-m walk test (10MWT), timed-up and go test (TUG test), 6-minute walk test (6MWT), and the walking index for SCI II (WISCI II) score. Secondary physiologic measures including the AIS with the lower extremity motor score (LEMS), the spinal spasticity (Ashworth scale), and the lower extremity circumferences.


METHODS
Subjects performed standardized functional testing before and after the 90 days of intervention.


RESULTS
Highly significant improvements of HAL-associated walking time, distance, and speed were noticed. Furthermore, significant improvements have been especially shown in the functional abilities without the exoskeleton for over-ground walking obtained in the 6MWT, TUG test, and the 10MWT, including an increase in the WISCI II score of three patients. Muscle strength (LEMS) increased in all patients accompanied by a gain of the lower limb circumferences. A conversion in the AIS was ascertained in one patient (ASIA B to ASIA C). One patient reported a decrease of spinal spasticity.


CONCLUSIONS
Hybrid assistive limb exoskeleton training results in improved over-ground walking and leads to the assumption of a beneficial effect on ambulatory mobility. However, evaluation in larger clinical trials is required.
Department of Spinal Cord Injuries, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44797, Bochum, Germany. Electronic address: bergmannsheil@bergmannsheil.de.
Mirko
M
Aach
Department of Spinal Cord Injuries, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44797, Bochum, Germany.
Oliver
O
Cruciger
Department of Neurology, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44797, Bochum, Germany.
Matthias
M
Sczesny-Kaiser
Department of Neurology, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44797, Bochum, Germany.
Oliver
O
Höffken
Department of Spinal Cord Injuries, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44797, Bochum, Germany.
Renate Ch
RCh
Meindl
Department of Neurology, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44797, Bochum, Germany.
Martin
M
Tegenthoff
Department of Neurology, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44797, Bochum, Germany.
Peter
P
Schwenkreis
Faculty of Engineering, Information and Systems, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-0006, Japan.
Yoshiyuki
Y
Sankai
Department of General and Trauma Surgery, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44797, Bochum, Germany.
Thomas A
TA
Schildhauer
D000203:Activities of Daily Living; D000328:Adult; D005080:Exercise Test / Q000379:methods*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D017063:Outcome Assessment, Health Care; D010264:Paraplegia / Q000209:etiology / Q000534:rehabilitation*; D010865:Pilot Projects; D012656:Self-Help Devices; D013119:Spinal Cord Injuries / Q000150:complications / Q000503:physiopathology / Q000534:rehabilitation*; D016138:Walking / Q000502:physiology*
Exoskeleton; Hybrid assistive limb; Paraplegia; Rehabilitation; Spinal cord injury; Treadmill training