In the usual knitting process, the sock is begun at the top and knitted toward the toe. Upon reaching the heel, the machine begins to move more slowly in a semicircular ("reciprocated") fashion to produce the heel pocket. It may be adjusted to reciprocate again at the toe to form a toe pocket. All socks do not have reciprocated toes and heels. For example, the basic tube styles have neither. The "fishmouth" toe closure is non-reciprocated but may be used on a stocking with a reciprocated heel.

A knitting process where upon reaching the heel, the machine begins to move slowly in an alternating fashion to produce the heel. The machine may be adjusted to complete the same process for the toe.