Every wondered about the parts of a stitch in knitting? I have designated five parts to help in clarifying some techniques. Naming these can help you see how stitches differ.
Parts of a Stitch
Front leg / Right leg This is the yarn as it comes from its anchor point or another stitch that sits in front of the needle. When the stitch is off the needle, it is the right leg.
Shoulders This is a pair, just like our shoulders! They are the widest point of the stitch as it sits on the needle before it goes over. When off the needle, the shoulders are before the stitch connects to the stitch above. They can be considered as right shoulder and left shoulder, or front or back.
Top The area between the shoulders, on the needle it is what sits on top of the needle. When off the needle, it is joined to the stitch above it. This is forward of the base of the legs in the second row of garter, or in purl stitches. The top is behind the base of the legs on knit stitch.
Back leg / Left leg This is the yarn as it goes behind the needle. When the stitch is off the needle, it is the left leg of the stitch. The back leg (loop by others) is often referenced when twisting stitches.
Yarn run The yarn running between two stitches.
How Stitches Interact
I have set these stitches up so the stitches on the right, labeled concave, show purls in two rows. They are labeled concave because the stitches tend to push the top of the stitch forward.
The stitches on the left represent a knit in a purl, or stockinette. I have labeled this convex because they push the top backwards, creating a convex curve. When this happens repetitively, we get the smooth surface of stockinette or jersey.