Plantar Fasciitis Orthopedic Insole Design And Effect Evaluation

Plantar fasciitis is a kind of foot disease that causes microscopic tearing of the plantar fascia due to foot ligament being affected for overstretched,and the incidence of plantar fasciitis is higher than other lower limb diseases.The effects of orthopedic insoles is well in the clinical treatment of plantar fasciitis,especially it can reduce foot pain in a short period of time.However,the mechanism of the effect of orthopedic insoles on the treatment of plantar fasciitis is currently unknown,and there is still little research on the effects of orthopedic insoles on the biomechanics of lower limbs in patients with plantar fasciitis.Therefore,the purpose of this experiment was to explore the effect of material hardness and insole arch support height on the immediate effect of lower limb biomechanics of plantar fasciitis patients and to evaluate the effect of orthopedic insoles on subjects in the short term.Method:Sixteen subjects were recruited in the experiment.The foot scanner was used to scan the subject’s feet,and a total of 9 types of orthopedic insoles were made based on their foot model for three combinations of different hardness and three different support heights.A cross-over randomized design was used where each insole was worn by sixteen subjects while three-dimensional motion data were collected in nine different conditions in the standard shoes.Insole comfort was measured on a 100mm visual analogue scale.Plantar pressure under the medial forefoot,lateral forefoot,midfoot,medial rearfoot,lateral rearfoot were recorded from 16 participants with plantar fasciitis using the Pedar-X system.Participants walked at their normal comfortable speed along an 10m walking in different condition.Main outcome measures were average pain(VAS)and walking distance.The collected index include plantar peak pressure,contact area,pressure time integral,step length,stand time,joint angle,joint moment,first peak ground reaction force,time to reach the first peak,loading rate,the root mean square of the gastrocnemius muscle,anterior tibial muscle and soleus muscle during the stand period.It is necessary to collect valid data three times in each case.According to the experimental results,,a set of optimal insole parameters were selected and made for subjects.Then these subjects check treating effective and repeat the experiment after they has wore insole 15 days or 30 days.Statistical analysis was performed on the results of the immediate experiment using two-factor repeated measures analysis of variance(ANOVA),and Tukey’s Post-Hoc test was used where significant differences were found(p<0.05).The intervention test was analyzed using one-way repeated ANOVA tests were performed to compare the three sessions conditions and the Tukey’s Post-Hoc test was used where significant differences were found(p<0.05)Results:The material hardness and support height of the orthopedic insole have a significant effect on the subject’s subjective comfort.The higher the insole support height,the greater the material hardness,and the stronger the subject’s pain in the midfoot area.In terms of plantar pressure distribution,different material hardness and support height also have significant effects on the plantar pressure distribution in the medial forefoot area,midfoot area,and medial heel area.The orthopedic insole with a hardness of 60°or 70° increases the peak pressure of the forefoot;with the increase of the arch support height,the peak pressure in the midfoot area also increases;the interaction of hardness and arch support have significant effect on the plantar peak pressure in heel mask.In terms of kinematics,the support height of the orthopedic insole only reduces the joint angle of the ankle on the frontal plane,and has no effect on the knee joint angle and gait parameters.The hardness of the material has only a significant difference in the impact of the ankle joint on the frontal plane,and there is no significant difference in the impact on other dynamic indicators.The follow-up experiment results showed that with the intervention of orthopedic insoles,the subjects’ daily walking distance has increased,and the maximum pain in the feet decreased significantly.However,intervention on the plantar pressure distribution did not have a significant effect.It has no significant effect on the joint angle and torque of the ankle joint,and only increases the abduction angle of the knee joint.The intervention effect of the orthopedic insole reduces the first peak of ground reaction force.Conclusion:The study found that the material hardness of Shore C70 and arch support height+5° were the optimal design parameters for orthopedic insoles.The intervention effect of orthopedic insoles made with these two parameters can effectively reduce foot pain and reduce tibial inversion and ankle valgus in patients with plantar fasciitis,and reduce lower limb muscle activity in patients with plantar fasciitis.It proves that the intervention effect of the orthopedic insole made by the optimized parameters is positive and effective.