A plumb line is a perfectly vertical line. It was used by the ancient Egyptians and up until recently to ensure tall buildings were built straight. A plumb line is usually a piece of cord that has a weight at one end, such as a ‘plum bob’ – derived from the Latin for lead (plumbum).
The posture plumb line is an imaginary straight line from the top of the head to the floor. In this model, perfect posture means our ears, shoulders, hips, knees, and ankles stack up along this line.
The concept of posture was thought to have originated in warfare as a means to improve the efficacy of weapons handling in the 16th century. By the end of the 18th century, it took on a broader meaning as a way to mold a man into a soldier with discipline.
In the 19th century, posture became closely associated with notions of health and illness. German anatomist Christian Wilhelm Braune brought the study of posture to medicine by dropping a plumb line down the backs of his research subjects and measuring the results. With trends like Swedish gymnastics and German krankengymnastics, antecedents of modern physiotherapy, the ideas of ideal posture and pathological postures were introduced.
With notions of illness go notions of morality and in the 20th-century posture became a political tool of eugenicists, who used it to bolster racist arguments about cultural superiority. Later, posture became a tool of teenage rebellion, and slouching became a way to show non-conformity and resistance to authority.
Description provided by Glenn Ruscoe of Australia.
References
Gilman E. 2013. “Stand up straight”: Notes toward a history of posture. Journal of Medical Humanities, 35, 57-83.
Jesson T. 2017. Upright and uptight: The invention of posture. Published on 3 May 2017 on the website www.medium.com, accessed online at https://medium.com/@thomas_jesson/upright-and-uptight-the-invention-of-posture-fe48282a4487 on 19 October 2021.
