Erector

Erector is a term with several distinct meanings in English. It can refer to a person or thing that erects or raises something, a set of back-related muscles in anatomy, or a line of construction toys known as the Erector Set. The intended meaning is usually clear from context and from accompanying terms.

In anatomy, the term is often associated with the erector spinae, a large muscle group running along the back that extends and stabilizes the spine. The group comprises three columns: iliocostalis, longissimus, and spinalis. These muscles work to keep the torso erect, assist in bending sideways, and play a role in posture. They are innervated by the dorsal rami of spinal nerves and are susceptible to strain through overuse or trauma.

Erector sets or Erector Sets are a historical line of construction toys created by the American inventor A. C. Gilbert in the early 20th century. The kits used metal rods, beams, nuts, bolts, and wheels to enable children to build mechanical models such as cranes, cars, and engines. The toy helped popularize engineering concepts and hands-on problem solving and became a staple of mid-century STEM play. Over the years, the brand passed through various owners and has seen multiple reissues and reinterpretations by different manufacturers.

As a general noun, erector refers to one who erects or raises something. In anatomy, terms such as erector spinae are common, though precise terminology is preferred. The term is sometimes used informally in reference to arrector pili muscles that raise body hair, though the standard term is arrector pili.