2.9. Activity Level

Activity level was measured by the knee scoring system of the Japanese Orthopaedic Association (JOA score), a confirmed, reliable tool [26]. There is a strong correlation between the activities of daily living grade of the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the JOA score [27]. The JOA score consists of pain on walking, pain on ascending or descending stairs, range of motion, and joint effusion. The items are scored from 0 to 30 points, 25 points, 35 points, and 10 points, respectively. A high score indicates a good activity level. We recorded the total score (lowest: 0 points; highest: 100 points).