"Insidious Toe-walking"

I hate insidious toe-walking.  Some argue that there is no such diagnosis.  If a child is toe-walking, there is a reason. Something is wrong if they are on their toes.  Let me tell you, some kids, it is so dang hard to tell why the heck they are toe-walking. It makes no sense.  I had an onslaught of toe-walkers come in.  Three evals in one week (which is a TON for the setting I am in by the way) and they are all toe-walkers.  Only one of them appears to possibly have any sensory issues and she is 13. 13 years old and just now she finally got sent to PT because she is toe-walking.  Her pediatrician has been telling her mother since this girl was 10 months old that she would grow out of it, the orthopedic who saw her 4 years ago told her to do calf stretches.  Seriously? What 9 year old kid is going to do calf stretches everyday, especially when they hurt.  This girl is in a ton of pain.  Whatever. So frustrating.  She ended up seeing a different orthopedic surgeon this last week and she is going to have surgery. Which is good...but anyway, back to toe walking. Another little girl comes in- she's almost three and not only does she walk on her toes, she walks on her tippy toes- like a little ballerina without toe shoes. She has the ability to walk flat footed, but as she fatigues she goes higher and higher up on her toes. What the heck? And then, the other girl is 6 and the first time I treated her after the eval, all I had to do to get her to walk with heel-toe progression is put a "squeaker" on her foot so every time she put her heel down it makes a squeaking sound and she walks heel-toe for the entire session.  What in the world? I don't understand toe-walking.