What Causes Leg To Give Out While Jumping, Tingling And Burning Sensation?

My 11 yr old daughter was playing at school today and she said she jumped and when she came down, her leg just gave out and she collapsed. When she went to stand up she said her leg was uncontrollably shaking and she couldnt get it to stop so she dropped again. The school personel carried her to the office because she could not walk without her leg giving out. She said it tingles at the knee cap when she stands on it for any length of time or you put pressure on the area. I wouldnt be too concerned, but when I talked to my doctor and told her that my daughter has serious hot flashes, as in one minute she is good, the next she feels like she is a hundred degrees (as she puts it) the doc. said it could be a thyroid issue and asked if I had that checked out. I read online where thyroid issues could also be a possible cause to this issue. Now I am wondering if self treatment is the smart thing to do here. She said she did not twist her leg when she jumped, her leg just gave out and she couldnt use it for a moment and now a tingling, burning sorta sensation when she stands on it is occurring. Any guesses? I dont think she had a stroke...