Comparison of peak cardiopulmonary performance parameters during robotics-assisted treadmill exercise and arm crank ergometry in incomplete spinal cord injury

Objective: (i) to compare cardiopulmonary performance parameters obtained from incremental exercise tests (IETs) performed using a robotics-assisted treadmill and an arm crank ergometer; (ii) to investigate test-retest reliability during both modes of exercise. Design: Each participant performed two IETs to the limit of tolerance on both a robotics-assisted treadmill and an arm crank ergometer. Setting: A Spinal Injuries Unit in the United Kingdom. Participants: 10 people with an incomplete spinal cord injury (SCI). Interventions: Not applicable. Main Outcome Measures: Peak oxygen uptake ((V) over dotO(2peak)), the gas exchange threshold (GET), peak heart rate (HRpeak) and peak lactate (Lactate(peak)) were obtained for each mode of assessment. The mean responses and test-retest reliability of the main outcome measures were determined and compared between modes of assessment. Results: (V) over dotO(2peak) was 16% higher (p = 0.016) and the. (V) over dotO(2) at the GET was 40% higher (p = 0.007) during the robotics-assisted treadmill exercise (RATE) IET. There was a trend for HRpeak to be higher during arm crank ergometry (ACE) (p = 0.058). Lactate(peak) was 46% higher (p = 0.006) during the ACE IET. During robotics-assisted exercise, the test-retest reliability was very high for. (V) over dotO(2peak) (r = 0.95), high for the GET (r = 0.75) and HRpeak (r = 0.88), and moderate for Lactate(peak) (r = 0.58). For ACE, the test-retest reliability was very high for. (V) over dotO(2peak) (r = 0.93), high for HRpeak (r = 0.81) and Lactate(peak) (r = 0.78), and low for the GET (r = 0.16). Conclusions: The results suggest that, when compared with ACE, RATE can be a highly effective stressor of the cardiopulmonary system, and may be a more appropriate mode of assessment to determine and monitor cardiopulmonary fitness in people with incomplete SCI.