Research Of 6DOF Motion Of Knee During The Walking And Single Knee Twisting Combine Squatting After Anterior Cruciate Ligament Deficiency

Background and objective:At present,Anterior cruciate ligament deficiency(ACLD)is diagnosed by clinicians based on inquiry,physical and imaging examinations,but there is no objective,fast and accurate quantitative method to obtain the dynamic characteristics of the knee joint.This research investigates the 6DOF motion of knee joints with4.5km/h treadmill walking and single knee twisting combine squatting.The kinematic characteristics of knee joint dynamic dysfunction after ACLD were analyzed to provide guidance for clinical treatment and rehabilitation.Methods:Twenty-one patients diagnosed with unilateral ACLD admitted to the Department of Sports Medicine,Shanghai Sixth People’s Hospital from October 2019 to October2020 were enrolled in this study.The six degrees of freedom(Varus-valgus,internal/external rotation,extension/flexion,anterior/posterior,proximal/distal,medial/lateral)of the knee were calculated by the Opti-knee digital navigation 3d dynamic evaluation system.In 4.5km/h treadmill walking,after collecting the motion of 6DOF,the range of motion of each degree of freedom was calculated,and the 6DOF motion at each critical moment of gait were selected.The frame where the maximum extension-flexion activity in the single knee twisting combine squatting was selected as6 DOF motion of the peak flexion.Subjects were scored by the International Knee Literature Committee Assessment Form(IKDC)and Lysholm Knee Function Score.The results of MRI examination and intraoperative knee arthroscopy of the subjects were collected to confirm ACLD and ensure the accuracy of diagnosis.Paired sample T test was used to compare measurement data of 6DOF motion of affected and healthy knee joint in range of motion of 6DOF,motion of 6DOF of each critical moment of gait and peak flexion.The results of basic clinical data of patient,MRI examination and intraoperative knee arthroscopy were analyzed by descriptive statistics.Above results P<0.05 was considered to be statistically significant.Results:1.All subjects were diagnosed with ACLD with a mean age of 29.2 ±6.50 years,BMI of 26.6±4.40kg/m2,injury time of 12.5±15.08 weeks,IKDC score of 62.4 ±9.30 and Lysholm score of 59.6±10.12.2.In 4.5km/h treadmill walking,the extension-flexion range of the affected knee joint was reduced by 6.8±1.7°,and the proximal-distal range was decreased by 0.6±0.55 cm compared with that of the healthy knee joint.At initial contact,the flexion of affected knee joint increased by 4.8±1.05° compared with that of healthy knee joint.At peak flexion of stance phase,compared with the healthy side,the affected knee joint anterior translation decreased 0.6±0.69 cm,distal translation decreased 0.3±0.40 cm,and medial translation increased 0.4±0.57 cm.At peak extension of the stance phase,compared with the healthy side,the affected knee joint internal rotation and flexion increased 5.9 ±3.62° and 5.3±2.33°.At peak flexion of swing phase,the flexion,anterior and proximal translation of affected knee joint decreased 3.9±2.95°,0.6±0.89 cm and 1.0±0.88 cm respectively,internal rotation increased 0.6±0.72 cm,compared with that of healthy side.There was no significant difference in other results.3.At peak flexion of single knee twisting combine squatting,there were 5.1±4.14°,0.4±0.76 cm and 0.6±0.92 cm reduction in flexion,anterior translation and proximal translation respectively of the affected knee joint compared with the healthy side.There was no significant difference in other results.Conclusion:After ACL injury,Opti-Knee was used to measure the 6DOF motion of the knee joint on the 4.5km/h platform walking,and the corresponding kinematic differences could be displayed at range of motion and each critical moment of gait,and its kinematic characteristics could be obtained quickly and accurately in clinic.The results of the single knee twisting combine squatting did not display the difference between healthy and affected side of the knees of ACLD patients.The individual differences between the subjects’ exercise habits and abilities and the fear of the movement also affect the research results of this movement...