Dang, this hits close to home! Here's what I found helped in my case:
I tore a muscle in my groin/inner thigh when I was a kid, but didn't really know to have it checked out, etc. I'm goofy, and it was my right leg, so my front leg.
Every once and a while when skating, I'd get a sharp pain between my leg and groin, usually when lifting my knee up towards my chest (like during an ollie).
The key I found was stretching, specifically after skating. Stretching regularly is never a bad thing, but because that's such a core muscle group used in skating, it really helps to stretch right after the sesh, so it doesn't tighten up.
I'd recommend doing a lunge-type quadricep stretch, and also the "butterfly" stretch sometimes. Personally, I'll spend a few solid minutes doing that lunge stretch immediately after every sesh, and it's made a world of difference.
Hope that helps. Good luck!