I started stretching a year ago. I was averaging 5-6 hours a day and after 6 months I started having really bad knee pain. At first, I wasn't sure if it was related, I'm pretty active although up there in age, but 4 months later I stopped stretching and the pain started to get better, although it didn't disappear. Around a week ago I restarted stretching only a couple of hours a day, and the knee pain started to get bad again. Has anyone experienced something similar? Is it possible the stretching can be causing this?