Doing Judo last night I landed on my back a few times and it began to hurt, no big deal. This morning/today, I can barely walk. I NEVER cancel classes due to my own injuries, always tough it out, but it wasn't possible tonight. I can't even drive my manual transmission car. Of course, being a masochistic idiot, I didn't do a thing about it last night. Pain is concentrated near the base of my lats radiating out from the base of the spine. It is "back pain" so to speak rather than a muscle ache which worries me somewhat. Anyone have any ideas? I'm more wondering if I should do something about it or if it will pass. I'm absolutely obsessive about taking care of myself (despite being dumb enough to ignore it immediately) so if it's anything I should do to make sure this doesn't become a permanent problem (like my knee) please let me know. Thank you!