Effects of powered exoskeleton-assisted gait training in spinal cord injury: a randomized controlled pilot study

Abstract

Background
Robotic exoskeletons have emerged as a promising intervention for gait rehabilitation in individuals with spinal cord injury. Given the high cost and technical complexity of most of these systems limit their clinical application in daily life. Identifying the patient populations that would benefit the most from these devices might be the key to guiding the development of lower-complexity and more accessible exoskeleton designs.


Methods
This randomized controlled pilot study included individuals with SCI classified according to the American Spinal Injury Association Impairment Scale (ASIA A, B, and C). Participants were allocated to either an intervention group receiving powered exoskeleton-assisted gait training or a control group receiving conventional passive orthotic gait training. The rehabilitation program lasted 8 weeks. Outcome measures included cardiopulmonary efficiency parameters (oxygen consumption, metabolic cost of walking, and physiological cost index), functional walking performance (6-minute walk test and Walking Index for Spinal Cord Injury), Visual Analogue Scale for fatigue and 12 item short term health survey for quality-of-life measures, neurophysiological indices H-reflex to M-wave (H/M) and F-wave to M-wave (F/M) ratios to assess the degree of Spasticity, and pelvic floor pressure parameters (resting and maximum anal pressure) to assess pelvic floor and anorectal function.


Results
Participants with ASIA C (motor-incomplete) injuries demonstrated the most pronounced improvements after rehabilitation. The intervention subgroup showed significantly lower metabolic cost and reduced physiological cost index. Trends toward improvement were also observed in aerobic capacity, walking endurance, gait symmetry, and pelvic floor parameters. In contrast, individuals with ASIA B injuries demonstrated modest cardiopulmonary improvements without significant functional gains, while ASIA A participants showed no statistically significant changes following rehabilitation.


Conclusion
Powered exoskeleton-assisted rehabilitation appears most beneficial for individuals with motor-incomplete SCI, where residual voluntary motor function can synergize with robotic assistance to improve walking efficiency. These findings support the development of simplified, lower-complexity exoskeleton systems targeting patients with incomplete injuries to enhance clinical accessibility and rehabilitation outcomes.