Abstract
We measured the anterior laxity of the normal knee in 100 Korean males and 50 Korean females without history of previous injury or symptoms on their knees. The test instrument was the model KT-2000 knee arthrometer, which is designed to record the relationship between anterior-posterior tibial force and displacement. The results were as follow: l. Average age, height and weight were 30.0 yrs, 167.4cm and 61.5kg. Mean thigh circumference was 41.9cm. 2. When tests were performed at 25 degrees of flexion mean displacements were 3.51mm with 151b and 4.38mm with 20lb. When quadriceps were tense, average laxities were 1.03mm and 1.39mm which were less than relaxed status by 6896 (p<0.001). Left knee was stiffer than right knee by 0.58mm (p<0.05). 3. Anterior laxities averaged 1.28mm with 151b and 1.78mm with 201b in 75 degrees of flexion, left knee was also stiffer than right. When quadriceps were tense average laxities were 0.72mm and 1.04mm which were less than relaxed status by 42%(p< 0.001). 4. Male knee was stiffer than female knee with differences of 3-5% in 25 degrees of flexion but stiffness of male knee were increased to 40% in 75 degrees of flexion and at active status of quadriceps. 5. The mean anterior compliance index was 0.87mm in 20 degrees flexion and 95% of subjects had compliance index no more than 1.8mm. The compliance index of male and female were 0.82mm and 0.95mm respectively. 6. The statistical analysis showed negative correlation between anterior laxity and age, height and weight. But ratio were too low to give explanation of meanings (age: r=-0.145, p<0.05, height: r=-0.090, p<0.05, weight: r=-0.075, p<0.05).