Both my wife and I have had that problem and usually find it is because our legs are not properly supported putting pressure on the sciatic nerve and reducing blood supply to our legs by restricting blood vessels. In our case lengthening the seat to provide this support solves the problem. On overnight trips we do this by putting our rolled up Thermarest pads directly in front of our seat. On day trips we often use just a rolled up peice of blue foam. These modifications make all the difference in the world.
There is a commercially available product designed specifically for this problem. Cascade Designs makes a "thigh support cushion" designed to alleviate pressure on blood vessels and the sciatic nerve. My wife has tried it and found it to work for her.
Edited by mikekayak (04/11/06 09:42 AM)