Hmm im not sure many babies do like tummy time. I rarely gave my DD's tummy time and they turned out fine and developed the same as other babies and hit milestones at the rough age that is in books. So far DS hates it too so he hasnt had much time either.
DD hated tummy time and it didn't affect her at all. She even HATED lying on her tummy on DP's chest which just about broke his heart, poor thing. Anyhow, she was one of the earliest crawlers at Mothers Group and walked at 12 months.
I haven't read the research so I shouldn't make generalisations but all I can say from my experience with DD is ... it's a croc.
I actually question the relevence too. I know lots of babies who hate tummy time so their mums didn't do it and they were fine? It would be interesting where they link the 2 things. I can see it helping with other issues, like flat heads, but once they can roll which is usually done before crawling they can roll to their tummies to crawl anyways.
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