I don't think it's common but my best friends LO, just a little over a year old at the time, started falling all the time, it was kinda crazy, so she took her to the doc. It turned out there was some virus that toddlers are prone to that she had. It gets into the joints. It went away after a couple weeks her LO was walking and playing just fine without all the falling.
I think, more commonly, that with big growth spurts there comes ungainliness. It passes pretty quickly as the kids adjust to their new size.