Study On Foot Type And Plantar Mechanical Characteristics Of Pregnant Women

Pregnancy is an experience that almost every woman has in their life.During the pregnancy,many women will experience foot edema,blistering,molting,cocoon,onychomycosis,beriberi and other symptoms.In addition,there are spine,lumbar pain,leg and foot varicose veins and so on.In this paper,the study group consists of twenty-two four-month pregnant women(the second trimester of pregnancy),a long-term and effective continuous tracking was carried out,while twenty non-pregnant women were chosen to contrast.The ways we use in this study are literature review,questionnaire survey,foot type measuring and plantar pressure measurements.The research we mainly conduct is to record the changes of pregnant women’s feet when they stand and walk with barefoot in different pregnancy period(13~27weeks gestation and 28~40weeks gestation)with the frequency of 1time per month in pregnancy period and 1 time 6 months later after delivery.By analyzing the foot shape(foot length,foot width,foot circumference,foot high),mechanical data(percentage of touchdown,phase,gait cycle,impulse,peak pressure and other indicators),and the results of the questionnaire survey,we’ve got some important outcomes,providing theoretical basis for the design of pregnant women shoes.The results were shown as follows:(1)Swelling is the most obvious phenomenon in gestation period.The survey showed that 77.2% of the pregnant women were accompanied with different degree of swelling.Foot swelling could lead to foot length,foot width,girth become bigger,shoes sizes of more than 70% pregnant women during pregnancy becomes large.Postpartum female foot size decreased compared with the pregnancy period,but still greater than non-pregnant women.The result showed that postpartum women swelling eased visibly,but the state can not recover completely.(2)The peak pressure in the regions of Metatarsal 3 and Metatarsal 4 during the pregnancy and postpartum.The pregnant women foot force impulse in the regions of Metatarsal 2 and Metatarsal 3.The non-pregnant women peak pressure and force impulse were in the Metatarsal 2 and Metatarsal 3 region.The results indicated pregnant women the force of the foot has been transferred,the deformation of the foot concentrated in the forefoot.(3)The maximum pressure load rate appeared in the region of heel and mid foot,which illustrated that the heel was the main force point in the different gestation and postpartum.The pregnant women in the second and third trimester of pregnancy,as well as postpartum women maximum pressure in the mid foot region was significantly higher than those of non-pregnant women.It indicated that pregnancy has a bad effect on woman’s feet.(4)The foot flat phase lasted most long time in the second and third trimester of pregnancy,and postpartum period compared with non-pregnant women.On the contrary,the forefoot push off phase was the most time-consuming for non-pregnant women.The pregnant women time used to complete a whole gait cycle is nearly twice as much as non-pregnant women,which revealed the main reason for slow pace and the gait of procrastination of pregnant women.