I had a dull pain on occasion, and made the mistake of riding with it, threw my back out so bad I couldn't stand up without dropping to the ground. Took me 45 minutes to stand up and get to my car.
After that I quit doing whips and other foot related tricks, and overall hardly rode. Been 3 years now, I just be as careful as I can, and things have been better. I know when that soreness comes up to quit for the day. It's partly why I hardly ride street anymore. Ramps seem to be less trouble for my back.
But yea, be careful. Mine turned out to be that my cartilage disc was about 1/3 the thickness it should be, and it slipped causing me to pinch nerves causing my legs to give out. Scary stuff. Took a long time to heal up enough to stand for a full work day. let alone ride for more than 15 minutes at a time.
"Hey anybody ever make that mistake like right when you wake up in the morning and you believe in yourself?" -Kyle Kinane
"BIKES!" -Tom Segura