Abstract
In patients with spinal cord injuries (n=8) and healthy controls (n=8) the hyperaemic response in the buttock skin after sitting on a hard surface was studied using a laser Doppler perfusion imager. They sat for three minutes (short load), or 15 minutes (long load). An exponential mathematical function was used to compare the mean perfusion during the observed interval. The results showed that preloading perfusion is significantly higher among patients than healthy subjects. In both groups, the microcirculation of the skin increased significantly after loading, and peak perfusion was significantly lower after the short load. The mean perfusion was higher among the patients after both loadings, which suggests that there was stronger ischaemic provocation. The main outcome was that there was a dose-response relation between duration of loading and intensity of reactive hyperaemia, and that patients with spinal cord injuries have greater perfusion before and after loading than healthy controls.