The number one question and answer for animators trying to use the HIK (Human IK full body rig) in Maya and MotionBuilder.
Note: The latest versions of the software have renamed Reach T and R to IK Blend T and R.
For artists useing Motionbuilder, understanding how the character controls work and how they effect the resulting animation is essential. Yet it is one of the most confusing areas to deal with when working with the Full body IK chracter rig in Motionbuilder (and also in Maya)
I see it as one of the most asked questions on the forums and so I wanted to post a few pages from our class PDF document. The PDF file explains what the pinning contorls do and how to use them and the reach contorls on the rig and what effect they have on the final animaton.
to the Mocap Club exampled guide to the character control rig .