Abstract
Seven male and three female subjects with no history of previous injury to their knees and two subjects with anterolateral rotatory instability were examined using a CYBEX to measure anterior displacement of tibia.
Anterior laxity of normal subjects averaged 4.9 millimeters in 45 degrees of flexion, while insufficient subjects averaged 12.0 millimeters.
Since anterior displacement of tibia is probably caused by patello-femoral compression force in association with activity of quadriceps femoris, rehabilitation of patients who underwent a repair for anterolateral rotatory instability should be done carefully and active ROM exercise should be done for assisting screw home movement which is opposed to anterolateral rotatory instability.
