Has anyone here suffered from knee problems, the chronic ones due to pacing too much. I usually have to pace while DDing. Sometimes it ends up being for hours. Until my knees are aching badly. I am afraid it may give rise to future knee problems. Though I am really unsure. I guess I am kinda young to have 'em right now. But yeah. Has anyone had problems similar to this due to pacing or some other intense activity that accompanies them during DDing?