Biomechanical Analysis Of The Movement Of The Healthy Side And The Affected Side Of The Lower Limb During Walking In Hemiplegic Patients

Research Objectives:In this study,by analyzing and comparing the dynamic external performance and dynamic internal muscle strength characteristics of the lower limb healthy side,affected side and normal gait of hemiplegic patients to explore the abnormal muscle strength performance of the healthy side and the affected side of the lower limbs of the hemiplegic patients when walking,especially the compensatory characteristics of the healthy side and the affected side of the lower limbs muscles,so as to provided a theoretical basis for the evaluation of lower limb function and rehabilitation training of hemiplegic patients;Research Methods:10 patients with post-stroke hemiplegia(Brunnstrom motor function phase 3)were selected from the rehabilitation department of the Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine to collect the three-dimensional kinematic data(180 Hz)of the complete gait of the lower limbs when walking and the synchronous ground reaction data(1000 Hz),combined with the inverse dynamics method to establish a dynamic simulation model,compared the biomechanical parameters of hemiplegic gait and normal gait lower extremity in a complete gait cycle,analyzed the changes of the angle,angular velocity and angular acceleration of the healthy and affected side joints of the hemiplegic patients,and quantified changes in joint torque and power of joint muscle groups of lower limbs;Research Results:1.During the initial landing period,the muscle torque values of the joints on the affected side are extremely low.The knee extensors,plantar flexors,and coronary hip abduction muscles on the healthy side are passively elongated to do negative work,and the knee on the healthy side of the hemiplegic gait,and the peak knee extensor torque of the healthy side of the hemiplegic gait was significantly higher than that of the normal gait.2.In the early stage of swing,the knee extension muscles of the healthy side passively elongate and do negative work during the knee flexion process.The peak torque of the knee extension is 1.10±0.13Nm/kg,which is significantly higher than the normal gait.The period of the knee flexion process is about 16.2%,which is larger than the normal gait(about 12%-14%).3.During the clearance of the affected side in the early stage of swinging,the healthy hip joint continued to abduct with an amplitude of 2.8 ±0.8°(while the normal gait movement during the same period showed continuous adduction),and the hip abductor muscle group showed active centripetal Contract to do positive work.At the same time,the healthy knee extensor muscle group and hip extensor muscle group actively contract to do positive work,and the peak power of the knee extensor muscle group to do positive work is significantly higher than normal gait;Research Conclusions:1.In the initial landing period,before the affected side touches the ground cushion,the extensor knee muscles,plantar flexors,and hip abductor muscles on the healthy side will start eccentric contraction to control the knee flexion,dorsiflexion,and hip adduction of the healthy side,and then compensate for the lack of 'cushioning function of the affected knee and ankle joints.2.In the early stage of swinging,the healthy side actively bends the knee,and the extensor muscle group performs negative work during the eccentric contraction process,which compensates for the lack of support function of the affected knee and ankle joints.It is recommended to strengthen the exercise of passive contraction control force of the healthy side extensor muscles of hemiplegic patients.3.In the early period of swinging,the healthy side hip joint continues to abduct to make the body incline,helping the affected leg to abduct to complete the foot clearance movement.At this time,the extensor muscles of the hip and knee joints(especially the knee joints)are actively doing positive work to generate the pedaling and stretching strength in order to make up for the lack of side extension function.It is suggested to strengthen the rapid strength exercise for active contraction of the knee extension muscle group of the healthy side of the hemiplegic patients and the centripetal contraction strength exercise of the healthy side with the far fixed hip abduction muscle group.