More than difference in meaning, I'd speak about difference in usage.
I find (1) and (2) to be similar in meaning, but I'd use (1) within a context of a list of damages:
1') We have a (more probably one) man injured, two women dead, and three children in shock.
There is a slight difference in emphasis: in a man injured the emphasis falls on injured, while in an injured man we are speaking about a man (emphasis on that noun) who happens to be injured (secondary information).
As regards (3) and (4), I think (4) is more likely to occur, for the reasons mentioned above and also because I don't like the proximity of the two participles, the past participle injured and the present participle lying, in (3). I think we could, or even should eliminate the comma in (4).