Harry picked up Hedwig’s cage, his Firebolt, and his rucksack, gave his unnaturally tidy bedroom one last sweeping look, and then made his ungainly way back downstairs to the hall, where he deposited cage, broomstick, and bag near the foot of the stairs.
There are no more uses of "ungainly" in the book.
Show samples from other sources
At that she flung her head high, spun on her ungainly legs and gallumphed back down the ridge apparently more indignant than afraid.
Farley Mowat -- Never Cry Wolf
We struggle with the ungainly thing, making all kinds of clanking noises as we wobble down the stairs.