Abonner for at downloade
Forced Tech Poses

Apparently techs can set player animation states. This tech lets you toggle through them.
Poses are standing, flying, falling, sitting, laying, ducking, walking, running, swimming, and none.
For comedic effect, unequipping the tech doesn't automatically reset the state to none, so feel free to mix and match your techs (at least until the pose resets itself on a load)
The tech is vanilla friendly, but has to be enabled with /enabletech forcepose