Another have here. 1st time in my gravel driveway, on a downhill curve on loose gravel at probably 1-2 mph. Only thing I could think of was Arty Johnson from laugh-in on his tricycle. Lay there spread eagle laughing my butt off. Didn't laugh the next 2 times, both in loose gravel, once more in my driveway. Have since relocated my driveway to level ground. No injuries, except to my pride. Glad it wasn't worse for you. Always get back on and enjoy.