Study design: Prospective randomized longitudinal clinical trial with matched controls.
Objectives: To investigate the long-term effect of training on postural control and extremity function after an acute anterior cruciate ligament (ACL) injury.
Background: ACL injuries may cause severe problems with recurrent giving way of the knee and reduced functional capacity. The effect of an acute ACL injury and the effect of various training programs on postural control, as well as the relation between postural control and extremity function after such an injury, have not been studied longitudinally.
Methods: Sixty-three consecutive patients, 35 men and 28 women (median age 24 years, quartiles 19-33 years), with an acute nonoperated ACL injury, randomized to neuromuscular supervised or self-monitored training, were examined with stabilometry (amplitude and average speed of center of pressure movements) and a one-leg hop test for distance after 6 weeks (stabilometry only), and after 3, 12, and 36 months, and were compared to a control group.
Results: Regardless of treatment, center of pressure amplitude was persistently higher in both the injured and uninjured legs during the 3-year follow-up, but average speed was less affected or unaffected compared to the control group. The one-leg hop had normalized in the neuromuscular group at the 12-month follow-up, but was shorter in both legs throughout the 3-year period in the self-monitored group. The median value (quartiles) for injured/uninjured legs at 3 months was 150 cm (120-174 cm)/177 cm (140-199 cm), at 12 months was 174 cm (140-200 cm)/180 cm (150-202 cm), and at 36 months was 172 cm (146-200 cm)/178 cm (150-200 cm) in the self-monitored group, compared to the control group (median 186 cm, quartiles 177-216 cm).
Conclusions: The higher center of pressure amplitude in both legs over the 3-year period indicate persistently impaired postural control in single-limb stance. However, functional performance, as measured with the one-leg hop test, was restored by neuromuscular training, but not by self-monitored training.