The Study On The Distribution Of Plantar Pressure In Diabetic Patients During Gait Cycle

Diabetic foot is a common complication of diabetes,characterized by hard-to-cure ulcers on the skin or tissue of the foot.The increase of plantar pressure is an important cause of diabetic foot.Therefore,the study on the distribution characteristics of plantar pressure in diabetic patients through plantar pressure experiment is of great significance to the prevention of diabetic foot and the development of auxiliary devices.A dynamic mechanical system is formed between the tissues of the foot and the shoe,and it is difficult to measure the mechanical state of the tissue in this system in real time.Therefore,it is uncertain whether the mechanical state of the internal tissues of the foot affects the plantar pressure in diabetic patients.In view of the above problems,this study uses the plantar pressure experiment combined with the multi-gait moment simulation of the foot to study the distribution law of plantar pressure and the mechanism of plantar pressure increase in diabetic patients,and buffers are made according to the test and simulation results.The design and optimization of decompression insole is of great significance for reducing the plantar pressure and the risk of tissue ulcers in diabetic patients.In this study,diabetic patients(DM),diabetic neuropathy patients(DPN),and control groups(NC)were selected as subjects.Plantar was divided to hindfoot region(H)、midfoot region(MF)、metatarsal region(MET)、phalangeal region(T).Peak force,peak pressure,and percentage of high pressure in differenced groups were analyzed using ANOVA one-way analysis of variance.Through CT/MRI scans and gait experiments,we obtained A healthy male’s lower limb CT and MRI and ground reaction force and the shank-ground angle.During the gait cycle were choosed flat foot,neutral,and push-off as the feature moment,and constructed a multi-tissue foot FEA model.Based on the multigait moment simulation of the foot,the plantar pressure,foot tissue stress and ground clearance angle under different plantar fascia hardness are obtained.Based on the peak pressure and high pressure percentage data,a pressure relief insole solution with Poron cushioning material embedded in the MET and H regions was designed,and the area of the cushioning structure(85%,90%,95%)and the sole-sole contact were designed.The shape is optimized,and finally the decompression effect of each scheme is compared and analyzed based on the plantar pressure experiment and multi-gait moment simulation.The plantar pressure test data showed that the peak MET force in the DM and DPN groups increased by 14.1% and 3.5%,respectively,and the peak H force increased by 14.3%and decreased by 6.2%,respectively,compared with the NC.Compared with NC,the absolute value of the difference between the peak force of the left and right feet in the DM and DPN groups was significantly reduced in the foot area outside the toe area,indicating that there is a uniform load on the left and right feet in the diabetic population.The.simulation results of the full gait cycle show that the stress of the plantar fascia at the first to third metatarsophalangeal joints increases with the stiffness of the plantar fascia,which is spatially consistent with the peak pressure changes in the MET and T bipedal regions.;Peak pressure was positively correlated with the degree of plantar fascia sclerosis and increased the risk of tissue ulceration in the MET and T-foot regions.The comparison experiment of the decompression insole scheme shows that the decompression effect of the S2 scheme with the cushion pad is 90% of the lateral distance is the best.The simulation comparison results of the optimized insole scheme show that the decompression ratio of the optimized decompression insole in MET and H is increased by 11.0% and 8.6%respectively compared with the S2 scheme,and the peak stress of the plantar fascia is increased by 1.9 MPa compared with the basic pad and the S2 scheme.