Visuomotor therapy modulates corticospinal excitability in patients following anterior cruciate ligament reconstruction: A randomized crossover trial

Background: Corticospinal adaptations have been observed following anterior cruciate ligament reconstruction around the time of returning to activity. These measures have been related to quadriceps strength deficits. Visuomotor therapy, combining motor control tasks with visual biofeedback, has been shown to increase corticospinal excitability. The purpose of this study was to assess the immediate changes of corticospinal excitability following a single session of visuomotor therapy in patients following anterior cruciate ligament reconstruction. Methods: This was a single blinded, sham-controlled crossover study. Ten patients following ACLR (8 Female, 26.1(6.2) years) completed assessments of quadriceps strength at approximately 4- and 6-months following anterior cruciate ligament reconstruction. At 6-months, quadriceps motor evoked potentials were assessed at 80%, 90%, 100%, 110%, 120%, 130%, 140%, and 150% of the patient's active motor threshold. Patients were randomized to receive a single session of visuomotor therapy(active) or passive motion(sham). Quadriceps motor evoked potentials were reassessed for treatment effect. Following a one-week washout period, all patients received the crossover intervention. Findings: Moderate to large increases in motor response following visuomotor therapy 90%(P =.008, r = 0.60), 110%(P =.038, r = 0.46), 120%(P =.021, r = 0.52), 130%(P =.021, r = 0.52), 140%(P =.008, r = 0.60) and 150%(P =.021, r = 0.52) of the active motor threshold were found. Moderate increases in motor response was observed following the passive motion at 80% of the active motor threshold(P =.028, r = 0.49). Interpretation: A single session of visuomotor therapy was found to increase quadriceps corticospinal motor response greater than the response to sham therapy. Visuomotor therapy is a potential supplement to quadriceps rehabilitation programs when upregulation of corticospinal excitability is indicated.