Move Around. Sitting in the same position for a prolonged period puts a great deal of stress on your spine and can increase the occurrence of blood clots, so get up and walk and stretch as frequently as possible. If you are not able to get up, pump (bend and straighten) your legs and feet periodically.
Leg Positioning. Airplane rides can be a bit tight and uncomfortable at times. If your legs are not positioned at a right angle when you sit in an airplane seat, use something to prop up your feet and keep your knees at a right angle. Doing so keeps stress off the lower back. If you have long legs, request an exit row (which generally has more leg room) and make sure you have room under the seat in front of you to extend your legs if needed.
Support your Low Back. Airplane seats do not provide good support for the lower back. Bring a back roll or small pillow to put behind your lower back for support. The blankets provided and folded, can also work well.
Support your Neck. Consider investing in a U-shaped neck pillow to allow your neck to rest, and to keep your neck from being strained if you happen to fall asleep. These are very affordable and can provide much relief if you struggle with neck pain. Also, be aware of your posturing and try to avoid slouching.
Choose Water. Flying dehydrates the body because of the very low humidity levels in the pressurized air cabin. Alcohol, tea, and coffee are diuretics that can encourage dehydration. Water will rehydrate the body and help to prevent circulatory problems.
Icing. If in acute pain, bring a couple of empty plastic baggies on your carry on. These will not be an issue to get through security and can be filled with ice once you’re at the gate and/or on board the plane.
Schedule Smart. Try to book a flight for a time of day when the plane is likely to be less full. With no one sitting next to you it will be easier to move and stretch while remaining in a sitting position, and to change sitting positions as needed.