Inertial dampers are the starship systems that absorb the forces of acceleration and sudden maneuvers, keeping crew members from being crushed or thrown about.
Starships change speed and direction far faster than any living body could tolerate. Inertial dampers create a compensating field that cancels most of the resulting forces, so the crew feels little more than a jolt even during violent maneuvers.
The system cannot respond instantly to every impact. Heavy weapons fire, collisions and power failures can briefly overwhelm it, which is why crews are often thrown from their stations during battle. A complete failure at speed would be fatal to everyone aboard.