Yes, because of the V2 rule, meaning that the verb wants to be the second part of a sentence. This sentence has four parts: ibland - sover - jag - på golvet. As we see, the verb follows the adverb if we move the adverb to the start of the sentence. If we instead go for a more direct word order, we get jag - sover - ibland - på golvet, where the verb is still in second position. It's even grammatically acceptable to say på golvet - sover - jag - ibland.
Does that clarify and/or exemplify it a bit for you?
Late answer, but yes, there's a subtle difference in what you communicate. The thing you put first in the sentence is the 'topic', the thing you start out with, usually the thing you're talking about. So very roughly it could be Ibland sover jag på golvet = statement about what sometimes happens while Jag sover på golvet ibland = statement about me.