Under the backdrop of the "Healthy China 2030" strategy, running has become the most common form of exercise. Fitness running is a kind of endurance aerobic exercise. Compared with swimming, aerobics, and other sports with high activity and intensity, the risk of lower limb fatigue injury during fitness running is higher. In this review paper, the risk factors for running-related injuries were summarized by consulting and analyzing the database and focuses on discussing and analyzing the impact of running on joints. The results showed that hip adduction, knee bending, and ankle joint abnormalities are the three joint-related factors that cause the main injuries during running. Four rehabilitation intervention methods for running-related injuries were proposed, that can guide patients to generate personalized rehabilitation treatment plans through training.

BACKGROUND:Ligaments are important structures in maintaining the stability of the lumbar spine,and these structures are prone to degradation due to the generated mechanical stress.However,there are few studies on ligament injuries. OBJECTIVE:To determine the range of motion and stress of each ligament in the state of motion based on a three-dimensional finite element model,and to systematically explore the influence of ligament injury on the stability of the lumbar spine and its biomechanical significance. METHODS:The L4-L5 lumbar finite element model was established.All free forces on the lower surface of L5 were constrained,and a torque of 5 N·m was applied to simulate the motion states of the lumbar spine.Progressive ligament damage was simulated by changing Young's modulus of the ligament. RESULTS AND CONCLUSION:(1)The extension range of motion of most ligament injuries increased significantly.In contrast,there was no significant change in the lateral bending range of motion.(2)The range of motion of capsular ligament injury increased significantly in flexion,extension and lateral bending.The extension range of motion increased significantly after the anterior longitudinal ligament injury.Intertransverse ligament injury resulted in a significant increase in the lateral bending range of motion.(3)After a single ligament injury,the most significant change in range of motion was observed during extension.After a single ligament injury,the stress of the remaining ligaments increased,especially the capsular ligament.The stress changes of the interspinous ligament and ligamentum flavum were the least obvious.Ligament stress changes least in lateral bending and most in torsion.(4)Ligament damage did not result in major changes in disc pressure,indicating that ligament injury leads to an increased range of motion of the lumbar spine and affects the stability of the lumbar spine.(5)Capsular ligament was stable in flexion,extension and lateral bending.The anterior longitudinal ligament showed a stable extension;the intertransverse ligament stabilizes the lateral curve.(6)Extension exercise is sensitive to a ligament injury,and the pathological changes of the ligament can be examined by extension exercise.(7)Stress compensation was given to the remaining ligaments to maintain the stability of the lumbar spine after a single ligament injury.(8)Interspinous ligament and ligamentum flavum injuries have the least impact on the peripheral ligaments,while capsular ligament injuries have the greatest impact on the peripheral ligaments.(9)The ligament injury has the least effect on the residual ligament stress during lateral bending exercise,while it has the greatest effect on the ligament stress during the twisting exercise.Patients with ligament injury should avoid twisting exercises.Ligament injuries do not affect disc pressure.

BACKGROUND:Ligaments are an important structure for stabilizing the lumbar spine,and they are prone to degenerative changes with age.Currently,there is limited research on lumbar ligaments. OBJECTIVE:To investigate the effect of different combinations of ligament injuries on biomechanical characteristics of lumbar spine under four motion states of forward bending,backward extension,lateral bending,and torsion under a certain sequence of ligament injuries. METHODS:A finite element model of the L4-L5 segment of the lumbar spine was established,and corresponding moments were applied to simulate four motion states of forward bending,backward extension,lateral bending,and torsion.The combined injuries of the ligaments were performed in order to obtain the motion range of each vertebra and the stress of each ligament. RESULTS AND CONCLUSION:(1)Every time a ligament was removed,the remaining ligament stress would increase.Under all four working conditions,capsular ligament would experience the highest stress,especially during forward bending.With the removal of ligaments,the range of motion of the vertebrae was also continuously increasing.(2)When flexing forward,after removing the first ligament capsular ligament,the average stress change in the remaining ligament was the highest,followed by the removal of supraspinous ligament.After removing capsular ligament,the change rate of range of motion was the highest,while after removing posterior longitudinal ligament,the change rate of range of motion was the lowest.(3)When extending backward,all ligaments had the highest rate of stress change after removing capsular ligament,the highest rate of range of motion change after removing capsular ligament,and the lowest rate of range of motion change after removing posterior longitudinal ligament.(4)When bending,the stress change rate of interspinous ligament decreased after removing intertransverse ligament,while supraspinous ligament increased more.After removing capsular ligament and interspinous ligament,the range of motion change rate increased significantly.(5)During lateral bending,after removing capsular ligament,the stress change rate of the remaining ligament was much higher than that of other ligament damage combinations,and the range of motion change rate was the highest after removing capsular ligament.In other cases,the range of motion change rate did not exceed 8%.(6)If the root ligament is damaged,the remaining ligaments will undergo stress compensation.Ligament damage will affect the stability of the lumbar spine,with minimal impact in cases of lateral curvature.Patients with lumbar instability should avoid forward flexion and backward extension movements,which can make it easier to detect the pathological condition of the ligaments.(7)Capsular ligament is an important structure for maintaining lumbar stability,and supraspinous ligament plays a significant role in anterior flexion,maintaining the integrity of the entire lumbar ligament.

Objective To compare the action effect of traditional and modified lumbar massage obliquity manipulation with different degrees of lumbar degeneration. Methods The biomechanical model of quality-spring-damping system lumbar spine was established and massage forces from professional massage doctors were collected. The force was used as input of the model, and lumbar degeneration was simulated by increasing elastic coefficient of the spring and damping coefficient of the damping in the model. By using MATLAB/ Simulink simulation technology, the effects of massage obliquity manipulation ( the maximum relative displacement and maximum acceleration) with different degrees of lumbar degeneration were obtained for comparative analysis.Results When the lumbar spine was degenerative, the maximum relative displacement and maximum acceleration of each segment were obtained under two manipulations. With the increase of lumbar degenerationdegree, the maximum relative displacement and maximum acceleration of each segment under two manipulations showed a downward trend, and the attenuation rate of the maximum relative displacement and maximum acceleration of each segment under two manipulations was obtained. Conclusions When degenerative changes in the spine do not occur, the effectiveness of traditional lumbar massage obliquity manipulation is slightly better than that of modified lumbar massage obliquity manipulation, but the safety of modified lumbar massage obliquity manipulation is obviously better than that of the traditional lumbar massage obliquity manipulation, so the modified lumbar massage obliquity manipulation should be used. With the aggravation of lumbar degeneration, the action effects of two manipulations are attenuated in a power function. The attenuation rate of effectiveness of modified lumbar massage obliquity manipulation is significantly faster than that of traditional lumbar massage obliquity manipulation, indicating that the modified lumbar massage obliquity manipulation should not be used in the caseof lumbar degeneration.