Effects of Knee Bracing on the Sensorimotor Function of Subjects with Anterior Cruciate Ligament Reconstruction

Abstract

The sensorimotor performance of the knee joint in 31 subjects who had undergone unilateral anterior cruciate ligament reconstruction at least 5 months previously was tested under three bracing conditions, 1) the DonJoy Legend brace, 2) a mechanical placebo brace, and 3) no brace, in random order. The accuracy of the subjects’ ability to reproduce specified knee joint angles was tested as well as the isokinetic performance of their knee muscles at 60 and 180 deg/sec. The results showed that subjects with the brace or placebo brace performed similarly in reproducing the knee joint positions, but both groups performed better than the subjects without a brace. Isokinetic tests revealed no difference among the three groups in extensor and flexor peak torque production at 60 deg/sec or total work done by the extensors and flexors at 60 and 180 deg/sec. These results suggest that knee bracing can improve the static proprioception of the knee joint, but not the muscle contractile function, in subjects with anterior cruciate ligament reconstruction under isokinetic testing conditions. The finding of similar performances for joint angle reproduction in the brace and placebo brace groups suggests that the apparent improvement in proprioception with knee bracing was not due to the mechanical restraining action of the brace.