IF I BEND DOWN MY KNEES CAN'T TAKE THE WEIGHT TO STAND BACK UP SO I HAVE TO HOLD ON TO SOMETHING.IF MY KNEES ARE BENT FOR ANY LONGER THAN A COUPLE OF MINUTES I NEED TO STRAIGHTEN THEM OUT BUT THEY HURT. IT SEEMS TO BE THE LEFT ONE MORE AND THE ACHE IS ON THE FRONT OF THE KNEE AROUND THE KNEECAP.