My son is 12 years old and is playing basketball, he had someone fall on the back of his leg, he complained about his ankle hurting when we got home his ankle was swollen and black and blue, we iced his ankle and he played the next day. His ankle has continued to be swollen all week, the inside of his knee has been swelling as well. We have rotated ice and heat for over a week, he still seems to have swelling and pain and now is complaining of burning in both and a feeling like they are both giving away. What could be some injuries that could be related to these symptoms.