if passengers drank a lot more water or juice and/or squirmed around in their seats a lot more , then DVT wouldn't be a problem.
But then they need more toilet visits, and on my last QF longhaul flight I was forbidden - by decree from the flight deck - to form a 'congregation' around the toilets, because as we know, all passengers are relatives of Osama Bin Laden and are bent on plotting a hijack unless prohibited from talking to another passenger; the ones seated next to you, and in front, and behind, don't count of course. Trying to work out exactly when to get out of ones' seat, to arrive at the toilet door first, and therefore not being made to walk the plank for disobeying the Captains' instructions, exercised my mind - and my bladder - for most of the 12 hr flight remaining after dinner. Fortunately, after many false starts, which involved walking seatbelt-less down the length of the aircraft and back many times, I made it. Phew! The relief was unbelievable. Next time I guess I'll pee on the floor - or use my empty beer can. Aussie Rules I guess ( and I never understood them, either. Wot's wrong with Rugby ? )