United Kingdom, Oct. 6 -- Britney Spears has injured her knee after falling down stairs.

The Gimme More singer - who has sons Preston, 19, and Jayden, 18, with ex-husband Kevin Federline - shared a video of her posing and dancing to Robin Thicke's 2006 single Lost Without U and offered an explanation in the caption as to why she could be seen with bandages on her right leg and her hands.

She wrote on the Instagram post: "My boys had to leave and go back to Maui.

"This is the way I express myself and pray through art... father who art in heaven... I'm not here for concern or pity, I just want to be a good woman and be better... and I do have wonderful support, so have a brilliant day !!!

"Psss I fell down the stairs at my friend's hous...