Using the Animation Rig
From The DarkMod Wiki
An overview of the animation controls on the latest animation rig.
IK/FK arm switch
In the default state the arms are set to FK. To switch the arms to Ik select the move control and look into the toolbox menu. You'll the next 2 options. Set both to 1 to set IK on the arms. The shape of the hand ctrl will change to a different controller