[fecak]

The study you linked appears to have one possible flaw. It reports on whether a child walked on their toes 'at some time'. In the many kids I've been around with autism, it's impossible not to notice the toe walking because it is so frequent. For our child, we would actually be more inclined to notice when she didn't toe walk.

If you combine this one with another couple symptoms, it's best to get it checked out.