Respiratory, cardiovascular and metabolic responses during different modes of overground bionic ambulation in persons with motor-incomplete spinal cord injury: A case series

• Main Authors: Jochen Kressler, Tracie Wymer, Antoinette Domingo
• Format: Article
• Language: English
• Published: Foundation for Rehabilitation Information 2017-09-01
• Series: Journal of Rehabilitation Medicine
• Subjects: walking; cardiovascular; exoskeleton; spinalcordinjury.
• Online Access: https://www.medicaljournals.se/jrm/content/html/10.2340/16501977-2281
• ISSN: 1650-1977; 1651-2081

Objective: To investigate the effects of overground bionic ambulation with variable assistance on cardiorespiratory and metabolic responses in persons with motor-incomplete spinal cord injury. Design: Case series. Subjects: Four participants with chronic, motor-incomplete spinal cord injury. Methods: Subjects completed a maximal graded exercise test on an arm-ergometer and 3 6-min bouts of overground bionic ambulation using different modes of assistance, i.e. Maximal, Adaptive, Fixed. Cardiorespiratory (oxygen consumption) and metabolic (caloric expenditure and substrate utilization) measures were taken using a mobile metabolic cart at each overground bionic ambulation assistance. Results: Cardiorespiratory responses ranged from low (24% VO2peak) for the least impaired and fittest individual to supramaximal (124% VO2peak) for the participant with the largest impairments and the lowest level of fitness. Different overground bionic ambulation assistive modes elicited small (3–8% VO2peak) differences in cardiorespiratory responses for 3 participants. One participant had a large (28% VO2peak) difference in cardiorespiratory responses to different modes of overground bionic ambulation. Metabolic responses mostly tracked closely with cardiorespiratory responses. Total energy expenditure ranged from 1.39 to 7.17 kcal/min. Fat oxidation ranged from 0.00 to 0.17 g/min across participants and different overground bionic ambulation modes. Conclusion: Overground bionic ambulation with variable assistance can substantially increase cardiorespiratory and metabolic responses; however, these responses vary widely across participants and overground bionic ambulation modes.