@helenczerski
1/2
When you sit still for long periods, your blood doesn't move that fast ... people are at risk of blood clots. When you take a brisk walk your blood moves a lot faster and it is partly because you are pointing and flexing your toes. Apparently that causes some valve action in your feet/ankles that moves the blood along.
People who sit for long periods (like in a plane) are encouraged to do a few reps of point/flex their toes periodically during flight to avoid blood clots.