From Pluralpedia, the collaborative plurality dictionary
Applies tosystem functions

A backlash is the feeling of a traumatic memory's emotional impact.

Usually, and normally; backlashes are felt a short period of time after a new, or existing, member fronts- and before they switch out/drift/float/move away from the fronting space.

The resulting feeling of a member that is fronting that is experiencing a backlash can range from; dizziness, confusion, trauma- related rage (even if it doesn’t belong to said member), blurriness and fatigue.

It is normal for said member to appear and the body to become very tired afterwards, to the point of that member temporarily being unable to fully control front for a couple moments before being able to stabilize the controls.