Function after anterior cruciate ligament injuries - Influence of visual control and proprioception

Information about limb positions and movements consists of input from visua l, vestibular, cutaneous, muscular, tendinous and joint receptors, but the relative contribution from each type and location of receptors is not known . The aim of this study was: a) to measure the contribution from Visual cen tral on extremity function, as measured with a one-leg hop test in healthy persons, in patients with an asymptomatic ACL injury, after non-operative t reatment and in patients with a stable knee after an ACL reconstruction, b) to investigate if there was any relation between proprioception from the e xtremity, as measured with the threshold for detecting passive motion of th e knee, and the one-leg hop test with a gradual decrease in Visual control. There was a decrease in hop-length when the subjects were deprived of visua l control that was significant when the dominant eye or both eyes were blin ded, both in the 2 patient groups and the reference population. The magnitu de of the length reduction did not differ between the groups or between inj ured and healthy limbs. In all 4 threshold tests performed as a measure of peripheral proprioceptio n, a stronger relation to hop-length was recorded for the blinded hop than with full visual control in the patients with nonoperated ACL injuries. The coefficients of correlation between hop-length and the proprioceptive reco rdings in the injured limb were of the same magnitude as on the healthy sid e.