Study On The Biomechanical Characteristics Of Lower Limbs In Patients With Flat Foot During Stairs Walking

With the development of society,stairs walking has become a common activity in people's life,and there are obvious differences in gait when normal people walking on stairs.As a common foot disease,flat foot's incidence is increasing year by year,the more and more affected population is suffering from it,so its prevention,treatment and correction have become an important issue that are worthy of attention.At present,the study of flat foot mainly involves the conditions of standing,ground walking and running,but the gait characteristics and motor function of flat foot under stair ascent and descent is still relatively unknown.Therefore,in order to reveal the movement mechanism of flat foot in the process under stair ascent and descent,this paper combines gait analysis,surface electromyography signal and plantar pressure to comprehensively explore the difference between stair walking and ground walking.Through walking test and theoretical analysis,this paper draws the following main conclusions:Compared with the normal foot,the plantar pressure of flat foot increased significantly during stair ascent,especially in the middle and rear foot area and part of the front foot area,the gait showed obvious instability.In order to avoid the larger impact of plantar force,the activation level and contraction rate of flat foot's LTA?LRF?LBF were significantly higher than that of normal foot,showing higher muscle activity.When going down the stairs,the force on the flat foot is less uniform than that on the normal foot,directly causing the angle of ankle dorsiflexion is obviously increased,LMG muscle activity is significantly enhanced,and LBF muscle activity is significantly decreased.Moreover for the whole stair walking process,flat foot's LMG contributes the most to lower limb muscle activity.Compared with ground walking,the flat foot required more time to complete a gait cycle when going up and down the stairs compared to walking on the flat ground,the percent of the first and second double stance phases have all increased,all require a larger range of joint angular motion.During stair ascent of flat foot,the pressure in the midfoot and part districts of the forefoot increased significantly,the impact force in the plantar increased significantly,and the muscle activity of the LTA?LBF increased significantly.The peak pressure in the MM area of the forefoot and the MA of the middle foot for flat foot is significantly higher under stair descent,and the peak pressure of the LT decreases obviously,which is related to the need for supporting the foot to push forward more and to weaken the pedal when it is off the ground;LRF muscle showed significantly greater muscle activity than walking on the ground,and LTA had smaller muscle contractions but LLG?LRF greater muscle contractions.This study fills the gap of the present research,the biomechanical characteristics of the lower limbs of flat foot walking under different road conditions were enriched.The above conclusions reveal not only the movement rule of flat foot under stair ascent and descent,but also the difference of gait characteristics between flat foot and normal foot,meanwhile provide reference guidance for the prevention and systematic exercise of flat foot.The quantitative analysis results provide some theoretical basis and data support for the optimization of flat foot correction insole.