European Journal of Applied Physiology

, Volume 85, Issue 1–2, pp 89–95

Cardiovascular responses during arm exercise and orthostatic challenge in individuals with paraplegia

  • Jacqui Raymond
  • Glen M. Davis
  • Jill Clarke
  • Grace Bryant
Original Article

DOI: 10.1007/s004210100449

Cite this article as:
Raymond, J., Davis, G.M., Clarke, J. et al. Eur J Appl Physiol (2001) 85: 89. doi:10.1007/s004210100449

Abstract.

In this study the cardiorespiratory responses during arm crank ergometry (ACE) performed at two submaximal intensities (30% and 50% of heart rate reserve) and moderate orthostatic challenge were investigated in individuals with paraplegia (PARA). The effect of concurrent electrical stimulation (ES)-induced leg muscle contractions on the responses to ACE during orthostatic challenge was also investigated. Eight PARA (T5–T12) and eight able-bodied (AB) individuals participated in this study, however only seven subjects from each group completed all tests and were used in subsequent data analyses. Oxygen uptake (\(\dot V{\rm O}_{\rm 2} \) ), heart rate (fc), stroke volume (SV) and cardiac output (\(\dot Q_{\rm c} \) ) were assessed during (1) ACE alone, (2) ACE and lower body negative pressure (ACE+LBNP), and, in PARA only, (3) ACE+LBNP with ES (ACE+LBNP+ES). In both PARA and AB, ACE+LBNP decreased SV (by 13–18% and 20–23%, respectively) and increased fc (by 13–15% and 16%, respectively) compared to ACE alone. The decrease in SV was greater in AB than in PARA (significant group × trial interaction; both ACE intensities pooled), but there was no difference in the magnitude of increase in fc between groups. ES-induced leg muscle contractions increased SV (up to 16%) but did not change \(\dot V{\rm O}_{\rm 2} \) or \(\dot Q_{\rm c} \) . The smaller reduction in SV from ACE to ACE+LBNP in PARA may indicate a mechanism by which adequate central blood volume can be maintained in the face of orthostatic challenge, despite the absence of supraspinal control below the spinal cord lesion. With ES-induced leg muscle contractions, the decrease in SV, which occurred during ACE+LBNP, was reversed via reactivation of the lower limb muscle pump and augmented venous return.

Electrical stimulation Cardiovascular Orthostatic challenge Spinal cord injury 

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • Jacqui Raymond
    • 1
  • Glen M. Davis
    • 1
  • Jill Clarke
    • 2
  • Grace Bryant
    • 3
  1. 1.Rehabilitation Research Centre, The University of Sydney, PO Box 170, Lidcombe, NSW 1825, Australia
  2. 2.School of Medical Radiation Technology, The University of Sydney, PO Box 170, Lidcombe, NSW 1825, Australia
  3. 3.School of Exercise and Sports Science, The University of Sydney, PO Box 170, Lidcombe, NSW 1825, Australia

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