The Anatomy of a Knitted Sock

I am not a rote learner. I cannot memorise to save my life. Things will not stick in my head if I just read it through. I can only learn by unpicking a concept inside out, and finding out all about the "whys" and "what ifs".

Sock knitting was a baffling conundrum of unfamiliar acronyms (W&T? RM? SSK?) and confusing stitch counts until I knitted enough socks to understand why I was casting on exactly that many number of stitches, and why I needed to place a marker in exactly that spot.

This post is a consolidation of what I understand socks to be.

A diagram of the different parts of the sock

Cuff

The cuff is the opening (or “mouth”) of the sock. It needs to be very elastic (stretchy but also tight at the same time) to keep the sock up the leg, or else the sock will droop down. Sock cuffs are made elastic with the use of the rib stitch (alternating knit and purl stitches). It also helps to use a material that is naturally elastic like wool, rather than a drapey material like cotton or linen.

Some socks are knitted “cuff down”, which means that the knitter starts at the sock and knits until they end at the toe. Socks that are knitted “toe up” start at the toe and end at the cuff.

Leg

The leg is the bit that goes from the cuff to the ankle. It’s knitted in the round, and if you’re feeling a bit adventurous, you can decorate it with different patterns.

Heel Flap

The heel flap is the part of the sock that goes behind your heel. It’s called a heel flap because if you knit from the cuff down, the heel is knitted as a flappy bit and is joined into the rest of the sock afterwards.

This part of the sock receives a lot of friction from rubbing against the back of the shoe. It is usually reinforced using a sturdy stitch like the Slip Stitch Heel (slip one, knit one, purl the alternate rows). It can also be reinforced by incorporating stronger fibres like nylon or mohair.

Heel Turn

The heel turn is where the sock makes a right angled turn to go from a vertical leg to a horizontal foot. It is curved to match the shape of the heel. This curve is made using short row knitting.

Gusset

Gussets are extra bits of fabric (can be any shape but usually triangle or diamond) added to an article of clothing to account for changes in the shape of a human body part or the movement of a joint.

In the case of a sock, the gusset is a triangle piece that is added between the heel, the instep and the sole of the sock. The gusset makes the sock wider to account for the shape of the foot joint.

Because the stitches on the heel flap are vertical and the stitches on the gusset are horizontal, there is an awkward join. The heel flap and the gusset are joined by picking up stitches if you're knitting cuff down socks and by regular decreases if you're knitting toe up socks.

Instep

The instep is the top of the foot at the joint where the leg meets the foot. It is knitted as usual while the gusset is being worked. If your sock has a pattern, you can continue the pattern down the instep.

Foot

The foot of the sock is the same as the foot of your foot. If your sock has an interesting pattern you can continue the pattern here, except on the sole of your sock. Make sure that the bottom of your sock is only stockinette stitch or else the sock will be uncomfortable to walk in.

Toe

As the foot gets narrower where the toes end, so does the sock. This is achieved by either decreasing or increasing the number of stitches in the sock to match the decreasing or increasing width of the foot.