Sunday, June 28, 2009
Not a pretty sight, and certainly not one you want to see below your knee on a trans-Atlantic flight. On average, it's a bad thing that airplane seats on such journeys are so close together that you can hardly reach your feet to pull off your shoes, but a good thing insofar as inspecting your ankles is difficult. But when I finally got my lower leg into viewing range on the leg of the trip from Madrid to Philadelphia, it was strictly Exhibit B for me!
This would be a good time to review venous return from the lower leg and all that might interfere with it during a summer flight. Consider blood and its journey from toe back to heart after its load of oxygen has been delivered to these nether regions. Each heartbeat sends a surge of blood through the elastic arteries which expand as the blood pushes by and then contract in a springy sort of way to amplify its forward progress. By the time the blood passes through the teeny weeny capillary bed back to the leg veins, however, it's a different story.
The veins which carry blood back to the heart are neither elastic nor springy. When the blood arrives in the venous system, that pulsing kick from the heart's action is much diminished. In the upright or seated position, gravity is tugging that old deoxygenated blood downwards. The veins have valves on their inner walls that open to partially prevent this gravitational backwash, and activation of the leg muscles helps to further squeeze venous blood in its upward course.
Think for a moment, then, about a middle-aged lady(MAL) stuck in a seat for 9 hours watching "Bride Wars" and "Marley and Me" and eating salty airline meals. Actually, the movie choices have nothing to do with our cankle tale here, but believe me, these were dismal ways to pass time. So the MAL has already walked too much through the hot Spanish sun with her venous system dilated from the heat and saggy with age. She's retaining water from the high salt food. Furthermore, as she sits motionless in steerage, two 90 degree turns in her leg veins (at the knees and the hips) further slow the flow.
Oh gad, methought, those are NOT my ankles (or more precisely, where are my ankles?). For those of you wondering when your ankle bones will re-emerge from the inflight edema, mine took two days and I've seen it take up to two weeks in some of my patients.