About 50-65% of all anterior cruciate ligament (ACL) injuries are reported to occur during landing from a jump or a one-step stop landing. These injuries typically occur during sports that require sudden deceleration movements or changes in direction, such as basketball, volleyball, and soccer. During landing, the functional role of the lower extremity is to generate, absorb, and transmit large forces as safely as possible. This functional role can be compromised when the ACL is injured. Only a third of ACL-injured athletes are able to continue sports like football, basketball or volleyball. Most athletes who want to stay active in those types of sports elect to have their injured ACL reconstructed. However, successful ACL reconstruction in terms of restoring the mechanical stability of the knee joint does not automatically mean restoration of normal knee function 3 . It has been shown that even for months and years after ACL reconstruction deficits in (1) gait , (2) running3) balance, (4) muscle strength, (5) proprioception and (6) jumping/landing persist. The findings of these functional deficits reported in the literature are not fully understood until now. It appears that patients sustaining an ACL injury develop an adaptive motor pattern. The ACL contains mechanoreceptors which relay proprioceptive information to the CNS . In fact,there is increasing evidence that a lesion of the ACL results in : 1) Modifications in the response properties of the Central Nervous System (CNS) such as increased response threshold or latency 2) Changes of the cortical representation by afferent inputs of the nearest areas; 3) Reorganization of the spinal input. These changes were present after injury of the ACL, but interestingly persisted after reconstruction of the ACL. Based on the aforementioned, we content that a lesion of the ACL should be regarded also as a neurophysiological lesion instead of only a simple musculoskeletal lesion. Summarizing, it appears that patients after ACL-injury and subsequent ACL-reconstruction hold on to a motor control program which may have been useful in the beginning stage but seems redundant > 6 months after ACL-reconstruction where mechanical stability has been almost fully restored. This implies that cognitive changes in motor control have occurred after injury of the ACL, indicating a lack of adaptability to reorganize the CNS after reconstruction of the ACL, hence, resulting in a disturbed motor control. Based on the above mentioned background it is expected that patients fail to modify their motor programming after ACL reconstruction. Furthermore, during the early stages of motor re-learning, the execution of movement requires much attention, so that there exists also a dependency on cognitive control. In earlier research it has been established that throughout the learning stages, dependency on cognitive and visual control of movement diminish to normal values and that motor control becomes automatic again, indicating that the reorganization of motor control systems is completed. However, patients after ACL reconstruction may fail to do so. The goal of the study is to gain insight in the changes in motor control programming after injury to the ACL and subsequent reconstruction of the ACL.
Door bewegingsanalyse verkrijgen van gegevens van de feitelijke bewegingspatronen en aanspanningspatronen in en rondom de knie na een VKB-reconstructie.