This study investigated whether a 60-minute arm-cranking exercise at 50 % of the individual maximal power output would increase lower limb skin blood flow (laser Doppler flowmetry) in individuals with high-level (T5 - T9; n = 6) and low-level paraplegia (T10 - T12; n = 6), compared to 6 able-bodied controls. Significant (P < 0.05) group by time interactions (two-way repeated measures ANOVA) were found for leg cutaneous vascular conductance, leg skin temperature and esophageal temperature. Cutaneous vascular conductance increased to a peak of ∼ 180 % of pre-exercise rest in both paraplegic groups and to ∼ 436 % in the control group, with differences after 15, 30, 45 and 60 minutes of exercise. Leg skin temperature increased by ∼ 0.3 °C in individuals with paraplegia and decreased by ∼ 2.0 °C in able-bodied. Esophageal temperature increases at the end of exercise were higher in individuals with paraplegia (∼ 0.9 °C) than in able-bodied subjects (∼ 0.5 °C). Heart rate was higher in the paraplegic groups than in able-bodied, whilst stroke volume and cardiac output were not different (impedance cardiography). The data suggest that lesion level had no influence on the results. These findings indicate that there is no excessive shunting of blood to the skin of the lower limbs of individuals with paraplegia during sustained exercise.
Spinal cord injury, laser Doppler flowmetry, active cutaneous vasodilation, esophageal temperature, skin temperature.
