Hi doctor , I recently got my left knee sprained during work. About 10 years ago, I had my ACL torn and done a surgery using my hamstring . Till now, I feel the pain comes back again. And I cannot stand/walk more than two hours. so, I went to family doctor and he wrote me a note for 2 months off. so, is my ACL starting to loosen up? can I still stand and walk for 8 or more hours a day because it is my job requirement.