The aim of this study was to investigate the plantar blood flow response to the same accumulated pressure stimulus in diabetic patients with different peak plantar pressure (PPP), which is important for assessing the risk of diabetic foot ulcer. Eleven diabetic subjects with high PPP (PPP ≥ 207 kPa) and 8 diabetic subjects with low PPP (PPP < 207 kPa) were asked to walk naturally on a treadmill so as to induce an accumulated stimulus of 73,000 kPa·s on their first metatarsal head, which was monitored with a sensorized insole. Blood perfusion (BP) in the first metatarsal head was measured before and after walking. Results showed that blood flow after applying the same walking stimulus was significantly decreased in comparison to the basal BP before walking in both high PPP and low PPP groups (p < 0.05), but no significant differences were found between the two groups in terms of BP parameters and its percentage change (p > 0.05). Moreover, BP parameters were not significantly correlated to PPP and the pressure-time integral (PTI) of the subjects' gait (p > 0.05). This indicated that, besides PPP and PTI, the accumulated mechanical stimulus should be taken into consideration when assessing the risk of diabetic patients developing foot ulcers. Graphical abstract Plantar blood flow response to a walking stimulus.
Keywords: Blood flow; Diabetic foot ulcer; Plantar pressure.