Dynamic Characteristics Analysis Of Knee Joint Motion During Walking

In the process of human movement,sports injuries are inevitable.These injuries mainly include sports injuries caused by athletic competition,damage to the musculoskeletal system caused by external loads,movement difficulties faced during rehabilitation,and movement restrictions caused by various bone,muscle,and joint diseases.Overcoming these difficulties is a major focus of modern biomechanics research.Researchers can simulate and analyze the kinematic and mechanical characteristics of the movement process to infer the causes of sports injuries and thus avoid potential risks.This also has guiding significance for the design and manufacture of rehabilitation equipment.Based on the theories of multibody dynamics and finite element analysis,this article used clinical CT images to establish a geometric model of the human lower limb using Mimics.A rigid multibody dynamics model and a flexible gradient-distributed material property model of the femur and tibia were constructed.Based on these models,a rigid-flexible coupled model of a single-sided femur and tibia and a knee bending model were also constructed with the femur and tibia treated as flexible bodies.Adams was used to perform dynamic simulation analysis on the three models.Using PD control and inverse dynamics calculation principles,the muscle force required to drive the single-sided knee joint bending model was calculated.The analysis showed that the joint torques,knee contact forces,and bone stress and strain of the lower limb model constructed from the clinical CT images during walking were similar to those of normal gait in terms of trend.The maximum bone stress was concentrated in the femoral shaft and the lower end of the femoral head,while the maximum tibial stress was concentrated in the middle of the tibia.The time period of the maximum stress on the femur and tibia occurred during the support phase.The muscle trends of the human knee joint model during bending were consistent on the same side,and the amplitude varied with the distribution position.The force exerted by the distal cross-joint muscles was larger than that of the proximal cross-joint muscles.Furthermore,the equivalent stress of the contact surface and the connection point of the ligament in the single-sided knee joint model were analyzed,and all three models obtained results consistent with expectations,indicating that the model construction theory has certain universality.