Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. I would like to know more information such as swelling, redness of the skin, and fever. Also, if you have a previous history of trauma or sprain in your ankle. Anyway based on limited information that you gave, the only conditions that comes in my mind is deep vein thrombosis or thrombophlebitis. This is a condition that happens in long hours of flight or position of legs downward and small blood clots are created in the deep veins of the leg causing pain, swelling, and redness of the skin. Usually, a Doppler ultrasound and blood test can confirm or exclude this diagnosis. The second option might be a lower back discal hernia but the pain pattern would be a bit different like you are describing. Sometimes, long drive can aggravate discal lumbar hernia so an MRI of the lower back would exclude that diagnosis. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Edvin Selmani