Biomenchanical Analysis on the pathogenesis of Knee Osteoarthrosis

The three-dimensional knee joint motion data during level walking were obtained from 34 males and 33 females using a 6-degree-of-freedom electrogoniometer. Normal motion pattern of active flexion (full extension to 20deg. flex.), active extension (20deg. flex. to full extension) and early stance phase during gait cycle were evaluated to find the physical difference based on sex and age. Adduction and internal rotation (male 85.3%, female 66.7%) were shown in the normal motion pattern during active flexion of the knees while abduction and external rotation (male 91.2%, female 90.9%) were found in the pattern during active extension of the knees.The screw home motion is detected during active extension (male 61.8%, female 90.9%). Adduction and internal rotation (male 97.1%, female 81.8%) were shown in the normal motion pattern during early stance phase. Females tend to change the pattern of motion with weight bearing. Adduction at early stance phase and abduction under active flexion are shown in females by 12.9%. On the other hand, there is the pattern change by only 2.9%, in males. This gender difference seems to be related to a general tendency of joint laxity in f emales