Toe standing/walking

Was anyone’s toddler a toe walker? What ended up happening?

So my son just turned 15 months. He is currently in PT because he still wasn’t crawling at 13 months. Now he’s doing excellent with crawling and is finally trying to pull up to stand.

But when we stand him up, he tends to stand on his toes. We have to physically put his feet flat and he won’t keep them flat for long before going back onto this top toes.

I am worried that he hasn’t started walking or anything because he has tight heel cords or something.

The PT said she isn’t worried “since she’s seen him stand flat footed,” but I can’t help but feel like something is wrong.

His 15 month well visit is soon and I’m definitely mentioning it to his pediatrician. But like what type of doctor would they even refer you to for this problem?

Anyone ever had this happen, and if so how did it turn out?