In middle position it just about all depends on what happens in front of you.
  If no one has raised you can play all the same hands you would have in early position.
  You can also open up your starting requirements.
You are able to limp in now with hands like A10, KJ, Q10, or J10 suited.
  If there are a couple of limpers in front of you calling with any suited A , as well as medium suited connecters.
   The strength of these hands is in a multi way pot.
  That means of no one has limped in front of you it is probably best to just fold.
  There are still too many people to act behind you.
The nature of the opponents behind you also plays a very important part in how you play middle position.
  If there are very aggressive players acting hind you, you should be more cautious from middle position and even play it just like early position.
If there are tight players behind you who do not know how to use their late position advantage, then play middle position more aggressively.
Say, for example, you have J10 suited in middle position and one player has limped in front of you.
  If there is a very aggressive player behind you, one likes to raise with marginal hands once a pot develops, the limp in.
If, on the other hand, there are only very tight player behind you, you may want to raise.
By doing this, you will force some otherwise playable hands, giving you position after the flop.
  If you do get called or raised by one of these tight players, you know you are in trouble to a player who has position on you.