I'm sure you can probably find a dozen sites online that will suit your needs, but you can try starting at the [URL=http://secure.spts.org/]Sports Physical Therapy Section[/URL]. Scroll down a little bit and you'll see some courses that may be of interest.
California University of Pennsylvania may offer you some masters programs that may be what you are looking for. I don't know that you will get a lot of on-line athletic training, although I did see an ad for an on-line DPT the other day. Wow, how do you do that?