In the present study the microdialysis method is used to investigate biochemical changes within and around the joint simultaneously in both the resting state and in a joint that had been subjected to exercise. The aim of the present study was, by applying the microdialysis technique, to monitor markers of cartilage breakdown and inflammation in 2 different positions of the knee (inside and in the inner part of the knee capsule) in a group of human females with knee osteoarthritis over a period of 3 hours.