Indentation assessment of plantar foot tissue in diabetic patients

The authors investigated the biomechanical properties of the plantar foot tissue in diabetic patients using an ultrasound indentation system. Four neuropathic diabetes mellitus (DM) patients and four normal subjects were chosen for this study. Indentation tests were performed at four sites (the 1st metatarsal head, 2nd metatarsal head, big toe and heel) in selected postures. The tissue thickness and effective Young´s modulus were measured by the ultrasound indentation system. Statistic analyses showed that the Young´s moduli of DM patients were significantly higher than those of normal subjects at various sites. Meanwhile, the tissue thicknesses of DM patients were significantly (p<0.05) lower than those of normal subjects. The Young´s modulus at the 1st metatarsal head was significantly (p<0.05) higher than that at the other three sites in DM patients. This site dependence was not observed in the normal subjects