Rigging: Digital Orthopedia - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 262

Figure 9.24 Adding another scaling curl for the hand.
This means that the bones of the little finger follow the end of the hand arc, on up the line. Figure 9.24
shows which bones go with which ones in the hard arc. The index finger and its base simply become
disconnected children of the main hand bone. Also, the base and control of the hand arc, the base of the
thumb, and its IK controller all become disconnected children of the main hand bone. This way, when
you move the hand bone itself in Pose mode, the entire hand and finger structure follows along as it
should. This part of the armature and how we built it gives you a good idea of the complexity that can
be involved when rigging. If you really liked building this hand, then congratulations. You might have
what it takes to be a good rigger. If not, don't feel bad. There are lots of great pre-built rigs available,
and there is absolutely no shame in using them.
Toggle IK and Other Constraints
The arms of the character are currently only rigged for forward kinematics, for the reasons we've already
discussed. Many times though, you might want to anchor a hand temporarily, whether it be placing it on
a tabletop or having your character lean against a wall. The hand becomes locked in place, with the arm
getting its motion from the anchor point instead of the shoulder. In those cases, you'll want to use IK.
This is perhaps the trickiest thing we'll set up in this very basic rigging tutorial, but you should be able
to handle it by now.