I didn't realise myself that she had low muscle tine and friends and family were shocked as she had held her head and neck up early while on her belly and could stay like that for ages, she also loved to weight bear on her legs. It was picked up when the health nurse layed her on her back then put one finger in each of my dd's hand to grasp onto, at 6 months, her neck should have stayed up as she pulled her slowly (instead of hanging back) and her bum slid out from underneath and she wasn't helping at all to pull herself up. Combined with this she didn't roll very often and was a bit later with sitting etc so thats when we got sent to a paed physio. She gave us exercises to do at home. To be honest I am not sure how much it helped as I suspect she prob would have done things in her own time anyway, but then there was no harm done and made me feel like I was doing something! When we were discharged from the hosp physio program at 18 months the physio said you would never know now as she had completely caught up and was even ahead in some gross motor areas!