Something not well documented is the recent changes to WW that no longer export $jigglebone as in the past. Now you need to use the WW Bone Properties, which gives you access to most bone properties and settings.
Advanced Bone Settings (http://dev.wallworm.com/document/161/advanced_bone_settings.html)
Note that you still control $jointconstrain limits in the bone's IK (IK tab in the Command Panel).
Scenario for using Bone Properties:
If you have a model where the model appears to fall apart or droop/sag/stretch, you may need to apply a Bone Properties Attribute to your collision hull nodes.
1) Apply the Bone Properties to all the hull nodes.
2) Select each Hull and turn on these settings in the modify tab: Use General Bone Properties and $alwayscollapse.
3) Re-export the model.