To create twisted ribbing in your work you will combine knit and purl stitches in 'columns' and the stockinette stitch columns will all be worked through the back loops (tbl).
This type of ribbing is usually done as 1 by 1 Ribbing. It's most commonly used for the cuff of socks as it creates a firm edge that is less likely to stretch out of shape as much. The twisted stitch columns form an attractive design feature.
1x1 Twisted Ribbing will look a little differently depending on whether it's worked in the round of flat.
Worked flat you will be working the knit stitches on the RS through the back loops but on the WS you will be working the purl stitches through the back loops.
Worked Flat
Row 1 (RS): *K1 tbl, p1; rep to end.
Row 2 (WS): *K1, p1 tbl; rep to end.
Worked in the Round
Rnd 1: *K1 tbl, p1; rep to end.
See it in a video here:
