This variety gives a twisted effect like what you will see in a whipped running stitch.

Back stitch: Lay the foundation by doing a back stitch.

whipped back stitch1       whipped back stitch2
Fig 1: Take another thread and needle and bring it out through A. Pass the needle under the stitch A-B, from above, as shown. Do not pluck the fabric underneath.   Fig 2: Similarly, pass the needle under the stitch B-C, from above, as shown.
whipped back stitch3
Fig 3: Continue this process of taking the needle under each back stitch foundation to give it a twining effect.


Make sure that while taking the needle and thread under each running stitch, you do not pluck the fabric underneath. You can use a blunt needle to acheive this.
Make sure to leave the back stitch just a bit loose in order to allow the other thread to pass through it easily