| The development of researches on human biomechanics has provided significanttheoretical support for clinical diagnose, disease prevention, medical simulation,rehabilitation engineering, sports competition and aerospace industry. However, thereare still a lot of remaining problems in the field of human biomechanics. For example,the mechanism of joint diseases is yet not clearly known, the service life of artificialjoint is limited because of failure. Besides, there is still not a sophisticated databasefor human kinematics in our country. Consequently, the majority of clinically-usedjoint prostheses are imported from abroad, while the clinical outcomes prove thatthese products are not well-suited for Chinese. Therefore, it is very necessary tofurther study the human biomecha nics.With advanced method s used in modern biomechanical studies, this study, fromthe perspective of biology, mechanics and anatomy, focus on experimental andsimulation analysis of hip and knee joint biomechanics for both healthy subjects andsubjects with pathological joints. The objectives of this study are to provide data forestablishment of joint kinematics database for the Asian race, and to gain insight intothe movement patterns of hip and knee joint, pa thogenesis of joint disease, preventionof sports trauma and the optimal design of artificial joint.Through capture and analysis of lower extremity motions of Chinese duringdaily activities, it was found that the joint kinematics was influenced by age, genderand ethnic background. Compared with males, females demonstrated higher jointmotions in frontal plane and transverse plane. Meanwhile, gait ve loc ity and jointrange of motion during high flexion activities were different between Chinese andwest Caucasian. For the young subjects, knee joint motions during low flexionactivities were highly correlated to those during high flexion activities, whereas thisphenomenon was not de monstrated for the elde rly.The joint kinetics during gait for patients with ACL-ruptured knees was obtainedthrough inverse dynamic method. The results indicated that the kinematics andkinetics were not back to normal three months after ACL reconstruction. Besides, thestudy of correlation between active rotational stability and passive rotational stabilityde monstrated that the evaluation and diagnose method currently used in clinics cannot reflect the joint stability during gait.A finite element mode l of human knee joint with implanted prosthesis wascreated based on CT images. Through simulating the measurement of passive rotational stability of knee joint, it was found that the error between theoretical andexpe rimental results was no more than5%. Study on the relative motion ofpatellofemoral joint revealed that, with increasing flexion angle, the patellar implantrotated along the x-axis, and moved into the inferior and medial direction. Thedistribution of joint forces on the medial and lateral part was further investigated,which provided bases for understanding the role of mechanical factors in developmentof osteoarthritis (OA).The influence of total hip arthroplasty on stress distribution and vibration modeof femur was studied based on finite element analysis. The results indicated that theprosthesis changed the mechanical and structural properties of the intact femur, stressconcentration could be observed around the prosthesis neck, and the naturalfrequencies of femur were changed. Meanwhile, the study on contact mechanics ofnon-spherical hip joint showed that the rotational ellipsoid mode l produced lowerpeak contact stress and higher contact area than the spherical and rotational conchoidmod el, with a similar contact distribution as natural hip joint. |
