Gait Analysis Of Spastic Hemiplegia Patients Based On Dynamic Simulation

Objective: Stroke is one of the diseases with high morbidity and disability rate in our country.Because of the damage of central nervous system,stroke patients have hemiplegic motor dysfunction.Normal walking can not be separated from the orderly contraction of muscles.Therefore,the abnormal gait of hemiplegia is closely related to the contraction of muscles.The purpose of this thesis is to analyze the kinematics and kinetics data of lower limbs in hemiplegic gait.Through the comparison and analysis of hemiplegic and normal gait,i obtain the high muscular tension of lower limbs and locate the target of botulinum toxin A injection,so as to provide reference for rehabilitation treatment.Methods: Using Vicon 2.3 three-dimensional gait image analysis system,the motion trajectories of Marker points of two spastic hemiplegic patients were collected.Kinematics data were obtained through Nxeus operating system.Then the number of motion frames of 35 Marker points needed was obtained through TRC file.The dynamic model was established by importing the.SLF file into LifeMOD system.Then,the spatiotemporal parameters,kinematics,ground reaction force and muscle strength of the spastic hemiplegic gai are compared with the normal gait.Result: 1.There are asymmetries in step length,support phase,swing phase,support time and double support time of hemiplegic gait,and the gait speed is slowed down and the width is increased 2.The ankle joint has insufficient dorsiflexion angle in the support stage of the frontal axis and insufficient dorsiflexion moment in the landing stage,and even the second case has foot drop phenomenon in the hemiplegic gait.There is excessive adduction angle in the sagittal axis during the swing phase,which causes strephenopodia;the knee joint is limited in the swing phase flexion movement on the frontal axis;and the hip joint is limited in the swing phase flexion movement on the frontal axis.3.The ground reaction force on the healthy side of the hemiplegic gait is smaller than that of the normal gait range,and the overall change of the ground reaction force on the healthy side is gentle,but the decrease of the ground reaction is smaller than that on the affected side,which indicates that the support force on the affected side of the hemiplegic patients is insufficient to compensate with the healthy side when walking.4.On the muscle strength of ankle joint,there are insufficient gastrocnemius and soleus muscles on the affected side of hemiplegic patients,and insufficient acceleration of triceps pedal off the ground in support and off-ground phases,which leads to shorter swing distance of shank,shorter step length and lower step speed.The first patient with hemiplegia has a too high tension in the lateral head of the gastrocnemius muscle,causing the angle of plantation at the landing stage and the supporting stage to be too large.When the heel touches the ground,it only takes a short time to adjust the foot to bear the weight of the healthy side.In the off-ground stage,the plantar flexion is insufficient,resulting in inadequate passive flexion of the knee joint.At the same time,the knee extension and hip flexion are insufficient and the abduction angle is increased,which is only an adaptive change to maintain body balance by widening.Because the tension of medial head of gastrocnemius muscle and lateral head of gastrocnemius muscle is too high,the plantar flexion angle is too large in landing stage and supporting stage.When the heel touches the ground,the knee is overextended due to the weakness of hamstring muscle.The patient spends a long time adjusting the foot.At the same time,the hip joint stretches to reach the maximum hip angle at the initial stage of swing by increasing the hip flexion angle angd driving the knee flexion to swing the thigh forward,so the hip flexor muscle strength is weak.5.Because the degree and location of gastrocnemius muscle tension in two patients with spastic hemiplegia are different,the site and dose of botulinum toxin injection are different in rehabilitation clinic.Kinematics and kinetics data of the first and second patients with hemiplegia after 300 U and 270 U botulinum toxin treatment are improved.Conclusion:Modeling by forward dynamics simulation can be used to analyze the abnormal muscle strength of the gait muscles of spastic hemiplegia,and judge the site of high muscle tension in triceps surae,so as to provide effective guidance for the treatment of spasm.