RESUMO
Objective:To investigate the plantar pressure features of diabetic patients, and design the offloading structure of insole to reduce the plantar pressure and internal stress of the soft tissue. Methods:A three-dimensional finite element model of foot was established based on CT images. Hole structure was designed in the high plantar pressure area of diabetic patients. The effects of diameter, depth and interval of holes on plantar pressure was analyzed through orthogonal test and finite element analysis, to obtain the optimal scheme; and the offloading effect was analyzed with finite element analysis and experiment. Results:The peak plantar pressure was higher in diabetic patients than in healthy individuals. The holes with 5 mm diameter, 6 mm depth and 2 mm interval in metatarsal and calcaneus regions might effectively reduce the plantar pressure and internal stress of soft tissue, which was 15.6%, 45.6%, 53.5% and 10.1% less of the peak plantar pressure on toes, metatarsal, midfoot and calcaneus area, respectively, compared to walking without insoles. Conclusion:Finite element analysis is helpful to explore the internal stress of soft tissue in diabetic patients, and insole with hole structure can reduce the plantar pressure and internal stress of soft tissue.