Dynamic assessment of anterior cruciate ligament using an electronic force plate

The active force exerted by the movement of arms and trunk with the knee in extension was measured in 25 patients with anterior cruciate ligament deficient knee. The electronic force sensitive foot plate was used to measure the force. Two sets of measurements were carried out. The antero-posterior stress test for measurement of Fy and the rotational stress test for measurement of Mz. Peak values obtained in anterior cruciate deficient knee were compared with the normal knee on the other side. The measurement of the difference in Fy was found to be a reliable indicator of instability of the knee, but no significant difference was found in the peak torque values (Mz) between the two knees. This study suggests that this test may be useful in the objective measurement of knee instability. Details of the method used and its possible indications are discussed.