You can command your character to stand when you use the following slash command: /stand
Standing is the upright pre-combat position of your character as opposed to sitting.
A character can walk, run, jump, or engage in combat directly from a standing position. If the character is sitting, most actions will automatically change the position to standing.
It takes a short amount of time to stand from a sitting position and about equal amount of time to sit from a standing position, but almost no time to walk, run, jump, or engage in combat.