The Effect of Using a Powered Exoskeleton Technology Training Program on Joint Range of Motion on Spinal Cord Injured Individuals: A Pilot Study

BACKGROUND: Paralysis and loss of normal upright function is the most commonly acknowledged ongoing impairment related to spinal cord injury, although numerous co-morbidities exist. The risk and progress of some these conditions may be mitigated by upright function. Over-ground powered exoskeletons have the potential to provide many physical health benefits associated with upright mobility; however research into the specific effects of powered exoskeleton use on the joints does not yet exist. The ReWalkTM enables people with lower limb disabilities to carry out routine ambulatory functions such as walking, standing, sitting, and ascending/descending stairs. Changes in patients’ joint range of motion as a consequence of one week of intensive powered exoskeleton training as part of a physiotherapy program were investigated.

METHODS: Sixteen participants aged 21-69 years with spinal cord injury between C3 and T12 (ASIA Impairment Scale A-D) visited the therapy center. Passive range of motion of ankle dorsi-flexion, hip extension and shoulder internal rotation and extension was measured using goniometry. Participants then undertook the training program which included use of parallel bars, crutches, different surfaces, and stairs/sitting/standing/walking. The program is supplemented by the use of functional electrical stimulation, far-infrared heat therapy and physiotherapy for exercise preparation. After five days range of motion was re-measured. Paired t-tests were run on bilaterally averaged pre and post ranges of motion, accepted significance value was p≤0.05.

RESULTS: Mean dorsi-flexion increased from 1.7° (plantigrade = 0) to 6.9° (t(11)-6.3;p<0.001). Mean hip extension increased from 8.2° to 14.1° (t(13)-3.5;p=0.017). There were no significant changes to shoulder extension (pre-64.7, post-66.7°, n=9) or shoulder internal rotation (pre-74.3, post- 78.9°, n=11).

CONCLUSION: Although this was a pilot study and lacked a control condition, the addition of ReWalk™ technology was novel as part of a physiotherapy program. Participation in the training program appeared to result in significant increases in ankle dorsi-flexion and hip extension which may be beneficial for all types of ongoing upright weight-bearing therapy in this population.