Preventing flat head syndrome

pumpkinspice4321

My sister's friend's little boy is currently wearing a helmet for flat head. He looks adorable but I know his mom feels like crap over it. I don't know all the details but I started googling and that freaked me out.

I didn't realize how common this is and I would really like to avoid it the best I can. I read about tummy time but babies sleep a lot! On their backs! I found this mattress thingy - actually it is kind of like a wedge that goes on the mattress for the baby to sleep on. It is hard to describe so click here to see it.

How can you find out if this product ACTUALLY works? I have read there should be nothing in the crib so will this decrease the chance of flat head and increase the chance of SIDS? Anyone else feeling stressed about all these bad things that could happen? sigh.