jhoferLNW2332 Skeleton setToSetupPose() method sets all bones, constraints, slots, and draw order to their setup pose values, so it should be possible to reset them by this. Disabling and enabling GameObjects alone does not call setToSetupPose()
, so I think Spinebot's answer was confusing on that point.
For your information, resetting the physics constraints to their setup poses can also be done individually: PhysicsConstraint-setToSetupPose