Problem with weight paint and particles.

First of all saying hello to everyone as this is my first post on the forum. Well i’m not a new blender user, in fact i’ve been using it for two years now but just not taking it really seriously, i just made some models and things. So some days ago i decided to start my own animation. The fact is that i built up a character which had hair maked out of particles which i attached to the character’s head using vertex groups.
The problem came when i created the armature for the character and started making some poses. When i move the head bone which is attached to the head by some other vertex group, the head moves but the particle system which emulates the hair just stays in the same place as before and so the head remains without hair.
Someone could tell me a way to fix this?? Thanks!!