This is called the snorricam shot. . The shot is achieved by rigging a device holding a camera to the body of the actor. As the actor moves, the camera remains stabilized as the background shifts, creating a feeling of dizziness, panic, or paranoia.
I wanted to see if it was possible to create an entire cinematography reel from scratch. 1 month of prep, 2 months of shooting, and this is the result: