T. Smitts wrote: I think there have been examples of characters being beamed away in a sitting position and being rematerialized upright, so it's not a huge stretch.
Case in point: Chakotay being beamed away while piloting the doomed Maquis ship in "Caretaker". We seem him walking off the pad, rather than getting up off the floor.
Most likely that's done for the actors' convenience.....like when Ro and Geordi are intangible yet avoid falling through the deck floors. We can't be sure if the GALILEO SEVEN survivors didn't beam up in sitting positions, but we DO know Kirk, McCoy and Bailey had to crouch low before being transported to Balok's ship in THE CORBOMITE MANEUVER.
Both Enterprise transporters and Kelvan neutralizings involve temporary nonexistence of sorts. But since Shea was brought back right side up after being bounced around, it stands to reason Uhura and Chekov would return in sitting position whether chairs are beneath them or not....