I was making a rock garden yesterday evening and while sitting on the ground with my legs stretched out , I reached out to my left oto get the rock I wanted and my right knee made a pop sound, almost like someone cracked no rhere knuckles loudly. I am 62 and need to know what I can do for my knee, that is very sore. It hurts when trying to bend it, a lot, but not much sitting with my legs out. Please let me know what I should do for it.