Place this clip at the exact frame of the fall in your edit, then follow it with a bruh sound for the reaction shot, and save a scream meme for a second, bigger tumble later in the sequence if the video keeps escalating.
About this sound
This is a roughly sixteen second meme clip built around the Portuguese phrase caiu um anão Luisão, announcing that a dwarf named Luisão has fallen. The delivery stretches the mishap out far longer than a quick reaction, which gives it an awkward, slapstick feeling, turning a simple trip into an exaggerated moment listeners are meant to laugh at.