question: My left knee has been having some problems and i dont know if it is serious or not. on the inside of my left knee next to my knee cap when i bend and straighten it you feel a strange movement like something sliding back and fourth. sometimes this causes me pain and i also think that soemtimes my knee gives out. i have fallen quite a few times recently. about 4 years ago i had a fall which was quite hard and landed on that knee and evey since around that time my knee has been acting up. when i bend and straighten it yo also hear a weird grinding noise and i can feel the movement all the way around the knee to the back and sometimes when i bend and straighten it i get a weird uncomfortable feeling all the way to my foot. it is not always painful so im not sure if i should be concerned