The Effect of Neuroplasticity of the Brain on the Incidence of Anterior Cruciate Ligament Injury and the Effect of Injury this Ligament on Brain Function And Structure (Systematic Review)

Objective: The present study aimed to investigate neuroplasticity of the brain on the incidence of anterior cruciate ligament injury and the effect of injury this ligament on brain function and structure before ligament reconstruction, after ligament reconstruction, and after a period of rehabilitation exercises. Materials & Methods: Previous studies were conducted from PubMed, Scopus, Web of Science, Google Scholar, Science Direct, Medline, Pedro, Cinahl, SPORTDiscus, and Cochrane Database, (from 1970 to 2021), and also Persian and English keywords related to the research topic were used to search for articles. Results: 65 articles were found according to the search method. according to the inclusion and exclusion criteria, 24 articles were reviewed. 5 articles that prospectively, examined the affect of  neuroplasticity of the brain on the incidence of anterior cruciate ligament injury, concluded that the brains of persons who have later ruptured ligament, it was different from the uninjured persons, especially in the motor-sensory part of the cerebral cortex and cerebellum, which caused errors in the planning of movement in the brain of these persons. Another 10 articles that examined the effect of an anterior injury on brain function and structure observed changes in the level of the sensory cortex and motor cortex of the brain at least two weeks after the injury, which after one year these structural and functional changes were widely increased in injured persons compared to healthy persons. These studies also showed that ligament inefficiency, as well as mechanical receptor damage, cause reorganization of the central nervous system. Also, one of the most important findings in this section was that in injured persons compared to healthy persons, the control activity of motor-visual areas, and also their need for visual feedback have increased. The other 7 articles that examined these changes after ligament reconstruction concluded that the functional and structural changes resulting from the injury not only did not return to normal but also despite the reconstruction, these negative changes increased after a while. Two other articles examining these changes after a period of rehabilitation exercises concluded that functional and structural changes as well as corticospinal stimulation in these individuals not only did remain but was increasing. Conclusion:The results of previous research have shown that changes in the brain after injury not only persist after anterior cruciate ligament reconstruction but also increase afterward. Finally, the results of the present study showed that common rehabilitation exercises whose main focus is not on eliminating these functional and structural changes in the brain, can not eliminate this negative neuroplasty after injury, which is one of the important causes of secondary injury and subsequent complications. The article concludes that in developing exercises to prevent injury to this ligament, and also rehabilitation exercises, it is better in addition to traditional rehabilitation exercises, use the new principles of motor learning and exercises related to visual feedback to eliminate negative neuroplasticity created in the brain and create positive neuroplasticity to support this ligament.