Comparison of peak cardiopulmonary performance parameters during robotics-assisted treadmill exercise and arm crank ergometry in incomplete spinal cord injury
Affiliations: [a] Centre for Rehabilitation Engineering, Department of Mechanical Engineering, University of Glasgow, Glasgow, UK | [b] Queen Elizabeth National Spinal Injuries Unit, Southern General Hospital, Glasgow, UK | [c] The Scottish Centre for Innovation in Spinal Cord Injury (http://www.SCISCI.org.uk)
Correspondence:
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Address for correspondence: Professor Kenneth J. Hunt, Centre for Rehabilitation Engineering, Department of Mechanical Engineering, James Watt South Building, University of Glasgow, Glasgow G12 8QQ, UK. Tel.: +44 (0) 141 330 4340; Fax: +44 (0) 141 330 4343; E-mail: k.hunt@mech.gla.ac.uk.
Abstract: 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 (V̇O2peak), the gas exchange threshold (GET), peak heart rate (HRpeak) and peak lactate (Lactatepeak) 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:V̇O2peak was 16% higher (p= 0.016) and the V̇O2 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). Lactatepeak was 46% higher (p=0.006) during the ACE IET. During robotics-assisted exercise, the test-retest reliability was very high for V̇O2peak (r=0.95), high for the GET (r=0.75) and HRpeak (r=0.88), and moderate for Lactatepeak (r=0.58). For ACE, the test-retest reliability was very high for V̇O2peak (r=0.93), high for HRpeak (r =0.81) and Lactatepeak (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.
