Sagittal plane translation of the knee during stair walking - Comparison of healthy and anterior cruciate ligament deficient subjects

With an electrogoniometer system, we made bilateral measurements of the max imal sagittal plane anterior-posterior knee translations in 15 healthy subj ects (controls) and 14 patients with arthroscopically confirmed unilateral anterior cruciate ligament deficiency during two types of ascents and desce nts (straight and side). In both groups, during the ascent cycle the tibia moved anteriorly in relation to the femur, whereas during the descent cycle it moved posteriorly, There was wide individual variation in maximal trans lation in both the control and anterior cruciate ligament-deficient groups (range, I to 12 mm; mean, 7 mm). The maximal translations were similar in b oth groups (P > 0.05), but they occurred at a significantly smaller flexion angle in the injured knees (38 degrees +/- 8 degrees) than in the control and noninjured knees (44 degrees +/- 8 degrees) (P < 0.05). The translation during step ascent and descent did not differ between the injured and cont rol knees. These findings indicate that patients with anterior cruciate lig ament injuries are able to control abnormal anterior translation during nor mal activity.