Motor control after anterior cruciate ligament reconstruction

Almost every week, there is a report in the media that a well known athlete has torn the anterior cruciate ligament (ACL) of the knee.
Although often regarded as a necessity, ACL reconstruction does not guarantee a normal knee function. Many patients do not return to competitive sports, have a higher risk of re-injury and develop degeneration of the cartilage of the knee joint at a young age.
The first aim of the dissertation was to examine how the knee moves after surgery, and the results showed that patients reduce to load of the knee during walking and jumping. Unfortunately, patients who do not move the knee normally have an increased risk to tear the ACL again.
Therefore, the second and more important purpose, was to find a possible explanation. A theory was developed that patients have an increased attention on movement (internal focus) of the knee which affects the learning process to regain normal movements. An external focus means the attention is directed toward the result of the movement. In a novel experiment, patients were embedded in a virtual reality setting in order to distract them from their conscious control of the knee. The results showed that movement of the knee in patients can be favorable influenced.
The findings of this dissertation may indicate that it is time for a paradigm change for rehabilitation. Future rehabilitation that incorporate instructions with an external attentional focus may decrease the risk of tearing the ACL again and delay the onset of wear and tear of the knee.