Functional Connectivity After Anterior Cruciate Ligament Reconstruction

Background: Despite surgical reconstruction and rehabilitation, individuals after a primary anterior cruciate ligament injury have a significantly increased risk of relapse. The mechanisms for this increased risk may go beyond mere physiological and biomechanical changes of the reconstructed anterior cruciate ligament. The loss of ligamentous mechanoreceptors can affect sensory feedback and consequently result in a disrupted afferent input to the central nervous system. However, research on the neuroplasticity of the central nervous system after anterior cruciate ligament injury and more specifically on the cooperation between different brain areas (=functional connectivity) in motor execution and performance is limited. Research purpose: To investigate the changes in terms of functional connectivity in the brain after sustaining an anterior cruciate ligament injury and associated reconstruction? Population: * Patients after anterior cruciate ligament reconstruction * Healthy controls Protocol: First, all participants are required to complete several questionnaires regarding the level of anxiety and the functioning of the knee in daily activities and sports. In addition, during the baseline testing, participants will be required to perform an experiment while electrical brain activity is recorded by means of an electroencephalography (EEG) measurement. During this experiment, the participants will have to successively perform the following exercises: 10x knee extension from sitting (left and right), 10x bipodal squat from standing, 5x 30 seconds unipodal standing (left and right). The above protocol will be administered to the patient group for the first time 8 weeks after the anterior cruciate ligament reconstruction. When the patients do not need further rehabilitation, they will be invited a second time to execute the same protocol again. The control group will only have to carry out the above protocol once. Finally, for one year after the last test, the