I hurt my knee last night while ice skating, I fell extremely hard on it. At first it only hurt like it normally would but when I went to kneel down to take my skate off afterwards, I almost yelled in pain. It is now excruciating to kneel or touch the front lower part of my knee cap. At first it was also numb and a tad tingly, but now it is not. It hurts when anything brushed against it- even my own pants or my blanket when bed. Now, 24 hours later, the joint has also been cracking and does not feel quite right. It feels a little loose and generally unusable, as if thighs are moving around in there. Also, when I gently touch the affected area, I can feel things crackling and moving in my knee. What is it?