Have the same thing...my hips have spurs on them and have arthritis in both hips..if not that get your static nerve checked out
I'm afraid that you might not have hurt on your spine because of some sudden jirk or falling. Take a good massage on your back and a glass of hot milk with 2 pinches of turmeric powder mixed in it.
Also, you can have some pain relief medication meanwhile. Add protein rich diet in your food habits, because some time the pain in lower legs is because of your muscles need more proteins based on your metabolism and working routine.
A number of things; pinched nerve, pulled muscle, pelvic out of alignment. Try staying off it for a few days alternate with ice and heat 20 mins. If you haven't had any kind of injury or fall then go see a chiropractor they work well, but if due to an injury you or it doesn't get better you need to see a doctor.