Nancy Bush writes in Sock Knitting Master Class:

My inspiration for this sock design was a pair of socks from Estonia. The original socks were knitted by my friend Maimu Poldoja in a natural white wool yarn. I studied the cables and spent some time making samples to discover how they were worked so that the ribbing melted into the stockinette stitch cables and then emerged from the other side. I found that by making the cables a bit “unbalanced,” each of the 7 rib stitches found a place in the cable. I chose my favorite cast on—the double-start method— to provide a decorative and very elastic edge.

--Copyright, Interweave Press 2011