Animate > IK/FK Keys > Move IK to FK

This menu item moves the current IK handle to the last joint in its joint chain.

In a typical IK/FK rig, the IK handle does not move with the skeleton during FK manipulation and thus appears out of sync. This can cause confusion when there are many IK handles. When animating with IK and FK, you can use Move IK to FK to synchronize the IK handle’s position with the end effector’s position.

For example, before switching from FK to IK in your animation, you need to move the IK handle to the FK bone’s position so that the animation does not jump when the FK switches to IK.