The most effective way of keeping the blood flowing in the veins and therefore preventing DVT would be to keep moving normally.

However, in many instances we find that we are unable to keep the legs moving normally. Such situations are aircraft flights, coach, train and car journeys.

Aircraft flights in particular keep people sitting down for long periods of time. It can be very difficult to move you legs in your seat and there is not often much room to move around the airplane to any great extent. There are exercises recommended and some new devices to encourage you to move your legs. However, these need you to actively remember to use them and they don't work if you fall asleep or don't use them.

Graduated pressure stockings are a very useful way to increase blood flow in the leg veins that work even when you are asleep or not moving. The principle is shown in the animation on the left.

Slow flow in the veins is speeded up by compression of the legs and therefore of the veins within the legs. It is essential that such stockings are graduated pressure stockings ie: the pressure at the foot and ankle must be the highest and then should reduce as the stocking goes up the leg. If you have properly fitted graduated pressure stockings you do not need these to be full length - below knee stockings are sufficient.