Reliability and relatedness of peak VO2 assessments during body weight supported treadmill training and arm cycle ergometry in individuals with chronic motor incomplete spinal cord injury.

STUDY DESIGN: Prospective assessment as part of initial evaluations for randomized-controlled trial participation.

OBJECTIVES: To determine the test-retest reliability of peak VO2 testing during both robotically assisted body weight supported treadmill training (RABWSTT) and arm cycle ergometry and to assess whether a relationship exists between these two measurements in individuals with chronic motor incomplete spinal cord injury (CMISCI).

METHODS: Twenty-one participants with CMISCI enrolled in a 3- month, RABWSTT randomized-controlled trial. As part of their baseline assessments, individuals underwent VO2 peak assessments twice on separate days during both RABWSTT and arm cycle ergometry using a metabolic cart.

RESULTS: Peak oxygen consumption measured at baseline correlated significantly between repeated tests in the RABWSTT (r=0.96, P<0.01) and the arm ergometer (r=0.95, P<0.01). A Pearson correlation (r=0.87, P<0.01) existed between the peak VO2 measurements obtained using RABWSTT and arm ergometry, although Bland-Altman analysis suggested a more limited relationship with a bias of 1.1 favoring arm ergometry. This relationship was stronger for individuals with tetraplegia than for people with paraplegia.

CONCLUSION/CLINICAL RELEVANCE: Determination of VO2 peak during both RABWSTT and arm ergometry in individuals with CMISCI is highly reproducible. Furthermore, a moderate correlation exists between peak VO2 measured during RABWSTT and arm cycle ergometry in this population for individuals with tetraplegia. This correlation offers implications for future cardiovascular testing of individuals with CMISCI, as two reliable peak VO2 measurement techniques are possible.