Tremor in child's leg

[frozenmad]

My son was running around yesterday and when he stopped and bent his leg he had an involuntary tremor and couldn't stop his leg shaking. This lasted for around 30 minutes every time his leg went in a certain position. Is it likely to have just been a trapped nerve?

Did he have the ball of his foot on the floor? I think there is a nerve there that can make that happen if you are pressing on it at the right angle. Or at least it happens to me if I put my foot at a certain angle, always has done.

No, it was propped up on a chair.