I ve been playing basketball a lot lately and try to dunk. One time when I tried to jump, as soon as I left the ground a pain, similar to landing on a two foot spike, shoot up my leg. The pain lingers in my heel, but only a small amount. The pain intensifies when I jump, though. As I am typing this the lingering pain is still in my heel, but has also traveled up into my shin and has grown to hurt more. Please help me to identify what this pain is, and if is dangerous to my health