The gait analysis technique for the lower limbs is currently one of the important clinical research directions for the diagnosis, the treatment and the intervention of osteoarthritis. This paper reviews the current clinical applications of three gait analysis techniques, the pressure sensing technology (the plantar pressure system), the computer vision technology (the marked gait analysis system and the unmarked gait analysis system) and the wearable technology (the wearable sensor system). Comparison is made with respect to the measurement principle, the experimental method and the clinical application advantages and disadvantages of the asynchronous state analysis system. Due to its complicated operation and the high professional requirements, it is not conducive for non-professionals to operate the computer vision technology equipment. With the wearable inertial sensing system technology, the personal, intelligent and comfortable wearable devices could be used. Due to its outstanding technical advantages and wide application prospects, it is an important development direction in the field of the medical prevention and the medical security in the future.

This paper identifies the changes of the running gait after the ACL rupture and the further effects of the concomitant medial meniscus tear on the running gait changes after the ACL rupture. Based on the 3D motion capture analysis method, quantitative analyses are made for the changes of the running gait in the ACL-deficient patients (22 healthy controls, 8 isolated ACL-deficient patients, 8 ACL-deficient concomitant with medial meniscus tear patients). The results show that for the ACL-deficient knee joint, a significant decrease of the exogenous flexion moment is observed during jogging, which is not only related to the weakening of the extensor muscle strength of the ACL-deficient side, but also related to the change of the neuromuscular control mode. For the patients with ACL rupture combined with the medial meniscus tear, a significant external rotation instability of the knee is observed during jogging, which may be related to the reduced control of rotation stability caused by the medial meniscus posterior horn tear. It is suggested that in the rehabilitation training program for the ACL rupture patients, one should pay attention to their abnormal running gait and intensify the training of flexor and extensor muscles and rotational muscle group and the neuromuscular training to improve their abnormal running gait and reduce the risk of the secondary injury after the ACL rupture.

The lower limb gait analysis is an effective method to quantitatively analyze the biomechanical changes of the internal motion of the knee joint, as well as an effective way to study the occurrence, the development and the intervention of the knee osteoarthritis (KOA). Two kinds of gait analysis experimental systems and their principles are reviewed, as well as the changes of the KOA patients' 3D lower limb gait. Due to the complexity of the lower limb biomechanics and the limitations of the research technology, the technique of the 3D orthopedic insoles is still in the preliminary stage, and there is no consensus with respect to the therapeutic effect of the products, and they have not been mass-produced and used. Therefore, the application principle and the manufacture process of the 3D orthopaedic insoles in the KOA are emphatically discussed. The dynamic and static structures and the changes around the knee joint of patients with the KOA, as being widely used in the design and the production of the 3D orthopaedic insoles, provide an important solution for the early conservative treatment of the KOA. And it can not only meet the dual requirements of comfort and functionality for patients, but also significantly reduce the manufacturing cycle and cost.