Your infant might benefit from PT if they cannot do the following at the appropriate age
3 months old
*Lift head 45-90 degrees while on tummy
6 months old
*Actively roll from back to tummy
*Lift head and chest off supporting surface while on tummy
8 months old
*Sit independently
*Move onto hands and knees without support
10 months old
*Crawl on hands and knees
*Pull to stand
12 months old
*Stand alone or at furniture
*Cruise along furniture
*Take steps independently
18 months old
*Walk independently
*Lower to the floor without falling