Mackenzie hated it big time so in the end we didn't do it. I figured she would do it when she started to roll. Even then she rollded back quick smart. I was told constantly by the MCHN that is was SOOOOO important but i thought if she hated it as much as she did I wouldn't make her do it. She never crawled and walked at 13 months. Her neck strength was never an issue and we just did/do lots of crawling now to help with her co-ordination as they say this may not develop aswell as she didn't crawl but in saying that I can't see any issues with her co-ordination!