Energetic and cardiovascular responses to treadmill walking and stationary cycling in subjects with incomplete spinal cord injury

Abstract

Study design: Randomized controlled trail. Objectives: To investigate if people with incomplete spinal cord injury (SCI) can perform high-intensity weight-bearing exercise by comparing cardiovascular responses at maximal workloads during stationary cycling and treadmill walking, and to explore mechanical efficiencies at sub-maximal workloads. Setting: Sunnaas Rehabilitation Hospital, Nesoddtangen, Norway. Methods: Fifteen people with incomplete SCI and 15 healthy control subjects performed sub-maximal and maximal exercise tests of both stationary cycling and uphill treadmill walking on separate days. Oxygen uptake (VO 2 ; l min − 1 and ml kg − 1 min − 1 ), carbon dioxide production (VCO 2 ; l min − 1 ), respiratory exchange ratio (RER) and heart rate (HR) were continuously measured throughout the tests. Results: The SCI group showed no significant differences in peak VO 2 (2.42 ± 0.68 l min − 1 versus 2.58 ± 0.76 l min − 1 , P = 0.19) or other cardiovascular responses at maximal workloads for stationary cycling as compared with uphill treadmill walking, except for higher RER during the cycle test. The control subjects exhibited a significantly higher peak VO 2 during the treadmill test as compared with the cycle test (P = 0.007). Both groups had lower mechanical efficiency when walking as compared with cycling, but the mean difference between cycling and walking was not significantly different between the groups during sub-maximal workloads (P 40.24). Conclusion: Subjects with incomplete SCI were able to perform high-intensity weight-bearing exercise and exhibited similar mechanical efficiencies at sub-maximal workloads as healthy controls. Uphill walking might be a good alternative to weight-bearing exercise for increasing the physical capacity of people with incomplete SCI.

Effects of overground locomotor training on the ventilatory response to volitional treadmill walking in individuals with incomplete spinal cord injury: a pilot study

“…6 Although there has been substantial emphasis on the neuromuscular 7-9 and cardiovascular 10,11 adaptations following rehabilitation, adaptations of the pulmonary system of individuals with incomplete SCI (iSCI) in response to locomotor training have been less frequently studied.…”

Exercise testing protocol using a roller system for manual wheelchair users with spinal cord injury

“…Mean VO 2peak measured in the present study was similar to that found in previous studies of wheelchair ergometry and ACEs. 15,19,[35][36][37] Two previous studies 16,33 reported higher VO 2peak values than the present study, possibly reflecting the difference in sample populations; Torhaug and colleagues tested persons with paraplegia, and Wouda and colleagues focused on adults with SCI with an ASIA D classification. As 70% of participants from the present study had tetraplegia, we would expect mean VO 2peak values to be lower, as less active muscle mass yields lower metabolic rates.…”

“…These differences in speed may have resulted in higher RPE ratings for the same 30 W workload. 16,33 The ACE also required participants to use an unfamiliar cranking motion and activate the trunk and/ or upper extremity muscles to maintain an upright posture during testing. Wheelchair seating position is critical for lung function and activity performance for individuals with SCI, particularly those with tetraplegia.…”

“…where watt, E, and REE are the submaximal exercise load of 30 W, energy expenditure during exercise (Kcal•min -1 ), and resting energy expenditure (Kcal•min -1 ), respectively. 33,34 One caloric equivalent is represented by the figure 0.01433. Statistical analyses were conducted using the Statistical Package for the Social Science (version 24 SPSS Inc., Chicago, IL, US).…”

“…The present study supplements previous research findings that individuals with SCI are capable of performing high-intensity exercise. 33 However, the inherent heterogeneity of persons with SCI emphasizes the importance of individualizing exercise modes and programs to optimize health and fitness benefits. The RS used in the present study had the ability to control resistance based on each participant's maximal speed, promoting an individualized testing experience within a standard ramp protocol.…”