Gait Analysis And Simulation Of Human Lower Limbs Based On TKA

The knee is an easily injured joint because of its largest and most complex structure in human body.TKA has been used to treat advanced knee diseases.However,some of the patients are undergoing the failure of artificial joints after TKA,as arthroplasty is not once for all.Many researchers have done much research on sports biomechanics for studying the pathogenesis of osteoarthritis and the failure of artificial joints,but it’s still not clear.The study of sports biomechanics in China is relatively late,leading to imperfection in lots of fields.Therefore,it’s very necessary to further study sports biomechanics especially for Chinese.The research on human gait is more extensive in sports biomechanics.Gait can be used to characterize human movement during walking and running with its periodicity and stability.With advanced methods,such as 3D motion capture system,FE analysis,muscle-actuated simulation,this study focused on gait analysis and simulation of healthy person and patients with TKA.The results revealed the movement patterns of human lower limb joints and the effects on it of TKA.Meanwhile,the results played a guiding role in the optimal design of artificial knee joint and the rehabilitation after TKA.With kinematics analysis of young and elderly adults during walking and jogging based on 3D motion capture system,it was found that the velocity and stride of elderly adults were smaller than those of young adults.The age differences in spatiotemporal parameters are mainly due to the shorter stride of elderly adults.There were also age differences in joint angles during walking and jogging.The age differences in joint ranges of motion are relative to velocity.3D motion capture system and force platform were used to obtain kinematic and kinetic parameters of elderly women with injured knee and healthy subjects.The results indicated that patients had slower velocity,shorter stride,and longer double-foot support period than healthy subjects before TKA.Patients were more likely to use the knee joint in the healthy side.Injured knee can also affect the movement of the hip and ankle joints.The spatiotemporal parameters and joint moments of patients returned to normal 3 months after TKA.However,there were still significant differences between the lower limb joint angles of patients and those of healthy subjects.Combining the medical tomography technology and 3D reconstruction technology,the finite element analysis was carried out simulation of human gait.The contact stress distribution of the human knee model and artificial knee model were studied at four moments of standing,heel strike,mid-stance and toe-off.The femoral cartilage is most easily lead to abrasion and lesion in human knee joint.And the medial cartilage of the tibia is more likely to be worn than the lateral cartilage.The peak contact stress at tibial insert and femoral prosthesis were higher than other parts in artificial knee joint.These two parts are more easily lead to failure of artificial knee joint.The musculoskeletal model of a patient with TKA was established in OpenSim.The muscle strength and activation in the surgical and healthy sides and the actuated acceleration analysis were studied at 4 different speeds.The results showed that the muscle strength was decreased with speed.The muscle strength and activation in surgical and healthy sides were almost equal,while the function to center of mass were nearly the opposite.