You're not supposed to hold them down, but you are supposed to control the environment. Meaning go onto the floor and make a boundary around them, allowing them to have their seizure, but so they wont move about.
Also if you put something in their mouth they can choke on it.
To shove something in their mouth could turn out much worse than biting their tongue.
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Also, these things are coming from people that work with people with these issues or have these issues in their families.
Alicia's brother has them, as does my nephew.