The utilization of virtual realilty studying changes in motor control after ACL injury

Patients may fail to to fully utilize motor learning capabilities after
ACL-injury and subsequent ACL-reconstruction. It appears that cognitive
changes in motor control have occurred after injury of the ACL. It has been
shown that patients who have had an ACL-reconstruction have a 5-fold increase
to sustain the same injury when compared to non injured subjects.34 It is
currently not well understood what the cause of the significant increased risk
is. A possible cause that has been reported is that patients have an
ineffective motor control which places them at greater risk.34 If the causes of
these abnormal movement patterns are known, rehabilitation programs can be
developed and implemented to determine if and how these alterations can be
normalized or optimized. This research may aide in understanding how
rehabilitation may be improved.

The goal of the study is to investigate whether and to what extend conscious
control of the movements of the knee joint is present. Evidence is emerging
that patients use an attentional focus that is directed to conscious control of
the movements (internal focus). This strategy has been shown to be detrimental
in motor learning. The patients will be embedded in a virtual reality setting
in order to distract them from their conscious control of the knee. The
hypothesis is that patients reach a more normalized movement pattern, that is,
with a focus on the effects of the movements (external focus) in the virtual
reality setting versus the same biomechanical task in terms of stepping down a
20-cm box.

The study will be a observational study. Patients will be tested at 6 months
after surgery. Control subjects will be tested to establish reference values.

The burden of the research consists of the regular physical examination which
takes place in the context of routine checks after surgery. This study intended
to determine the suitability of patients for possible participation in the
study. Insofar as this physical examination takes place in the context of
regular patient care, therefore places no additional time requirements for the
patient. The measurements made when the patient gives his/her consent to
participation is in total duration 1 hour. The measurements are performed 6
months after surgery. Heavy physical work, according to the Directive Anterior
Cruciate Ligament of the Dutch Orthopaedic Society are allowed 3 months after
surgery. In general at 6 months, patients either entirely or partially return
to sports. The task of the research is to move from box 20 cm high. For
clarity, this is similar to the height of a stair. In this sense, the
researchers consider the risk as very low since it is similar to an everyday
task like stairs and down.