Relationship between heart rate and oxygen uptake during submaximal arm cranking in paraplegics and quadriplegics

The purpose of this study was to clarify the effect of the level of spinal cord injury (SCI) and of daily exercise on the relationship between heart rate (HR) and oxygen uptake (VO2) in persons with SCI (PSCI) during an arm cranking exercise. Eighteen PSCI were divided into three groups according to the level of SCI; 4 quadriplegics (C6-C8), 7 high- level paraplegics (T3-T8), and 7 low-level paraplegics (T10-L2). In the relationship between HR and VO2, the higher the level of SCI, the smaller the slope of regression line, that means the HR at a given VO2 become larger as level of SCI was higher. Significant differences were found among these regression lines (P < 0.01). In addition, the regression lines between HR and VO2 in active persons tended to shift toward upper in comparison with those in inactive persons. The present investigation clearly shows that the HR-VO2 relationship in PSCI is remarkably influenced by the level SCI and physical training.