You can lock an object’s ability to move, rotate, or scale about any of its local axes by selecting objects and then setting options on the Locks rollout of the Hierarchy panel.

Enabling and disabling Local transform axes is also referred to as setting degrees of freedom (DoF) for an object. If an axis is enabled, an object is free to transform about that Local axis.

The Locks rollout contains three groups: one each for Move, Rotate, and Scale. Each group contains three options, one each for the X, Y, and Z Local axes of the selected objects.

• When turned on, the objects cannot be transformed about the selected Local axes when you directly use one of the transform tools.

  Objects can still be transformed by other means such as being a child of a transformed parent object or being part of an inverse kinematics chain.

• When turned off, objects can be freely transformed about the unlocked Local axes.