Rotate Body while playing Animation with Mecanim

Hello everybody

i created my own character rigged. to start learning the 3rd person controller stuff in unity3d

i have 5 animation, [idle , walk forward , backward , left , right]

i used Mecanim to animate my character, and everything works fine

but what i'm trying to do

is to let the animation apply only on the Legs

so i can control the upperbody with my mouse

     transform.localEulerAngles = new Vector3(-rotationX, transform.localEulerAngles.y,rotationZ);

so i can let him aim at enemy [just like any 3rd person shooter game]

so i used avatar mask to let him only play animation for legs

and now the animation only apply in legs successfully

but the upperbody is freezing, its not moving using my script

but i tried my script without playing any animation and works fine

do u have idea about this? hope you can help me

sry for bad english,, and thanks