Effects Of Internal Contact Unstable Structure Insole On Biomechanics Of Lower Extremities

Objective: The concept of unstable structural shoes is to rely on the design concept of unstable training equipment,to design the sole structure into an unstable convex surface,the change of the sole structure,resulting in the human body in the walking state of "instability".It forces the human body to adjust the posture constantly and strengthen the muscle activation to maintain the balance of the body.This research combines the design idea of unstable shoe tools,at the same time,by adding unstable structural elements to the midfoot area of the insole,it fits directly with the sole.Furthermore,the kinematics and dynamics of lower extremities and the characteristics of foot pressure caused by unstable structure are further verified,and the human body wearing the experimental shoes of internal contact unstable structure is discussed.The effects of normal walking and jogging on human function in normal walking and jogging on human lower limb motion system were verified by comparing shoes with normal walking and jogging in the process of normal walking and jogging.Methods: Twelve women took part in the test.The common sports shoes were selected as the control group,and the experimental group was the sports shoes with unstable structure with protruding in front of the midfoot of the shoe sole in the experimental group.The rest of the position was slightly sunk.Walking and jogging were used to test the biomechanical data of the lower limbs of the subjects' right leg in a gait cycle.an 8-camera Vicon motion analysis system,force measuring platform and Novel Pedar sole pressure measurement system were used to collect relevant data synchronously.SPSS 17.0 software(SPSS,Chicago,IL,US),was used to analyze the difference of kinematics and dynamics between experimental shoes and control shoes by paired sample T test.The significance level was set at 0 05.Results: The step of walking and jogging of the worn-in-contact type unstable shoes was significantly lower than that of ordinary shoes(p <0.05).When walking,the hip joint of the shoes with the unstable structure is larger in the sagittal plane,the range of the vertical plane is smaller,the peak buckling and the stretching angle are higher than that of the normal shoes.The flexion angle of the knee joint at the time of walking was large,and the peak angle of the inside and outside of the coronal plane was significantly reduced and the range of activity was small(P<0.05).The angle of the back of the ankle joint of the worn-in contact type unstable structure is larger.The peak angle of metatarsal flexion was larger(P < 0.05),the angle of valgus peak in coronal plane was increased,and the activity in vertical plane was smaller(P < 0.05).During jogging,the flexion angle of hip joint was increased,while the peak angle of flexion decreased while the angle of extension peak increased(P < 0.05),and the angle of internal rotation in vertical plane generally increased when the heel just landed in the sagittal plane wearing the inner contact unstable structure shoe(P < 0.05).The peak angle of ankle metatarsal flexion and internal rotation decreased when wearing internal contact unstable structure shoes,and the motion of knee joint and ankle joint decreased significantly(P < 0.05)when wearing the inner touch unstable structure shoes(P < 0.05),compared with the normal shoes,the motion of knee joint and ankle joint decreased significantly(P < 0.05).0.05)The growth rate of vertical load in normal sports shoes was significantly higher than that in internal contact unstable structural shoes(P < 0.05).The plantar contact area was larger in the shoes with unstable inner touch structure,especially in the toe area,in the medial part of the anterior metacarpal and in the midfoot(P < 0.05).The peak pressure of the whole foremetacarpal part and heel was lower in the big toe area of unstable shoes during walking and jogging(P < 0.05),and the time pressure integral of other parts except the lateral part of anterior metacarpal and midfoot area was also significantly decreased(P < 0.05).Conclusion: The ankle,knee,and hip angle of the lower limb during walking and jogging of the through-contact type unstable structural shoe pad have obvious changes with the general sports shoes,in particular the joint angle and the peak angle of the heel just after the ground.In that running state,the insole of the through-contact type unstable structure makes the growth rate of the vertical load and the peak value of the passive impact force to be significantly reduced.In that method,the contact area of the middle-foot area is increased when the insoles of the unstable structure are worn,and the peak pressure and the time-pressure integral of the middle-foot area are remarkably reduced,and the stress borne by the plantar region of the sole is reduced.