{"id":19716,"date":"2020-08-27T11:00:41","date_gmt":"2020-08-27T15:00:41","guid":{"rendered":"https:\/\/circulatingnow.nlm.nih.gov\/?p=19716"},"modified":"2020-08-20T16:48:04","modified_gmt":"2020-08-20T20:48:04","slug":"mechanics-of-the-human-walking-apparatus-1836","status":"publish","type":"post","link":"https:\/\/circulatingnow.nlm.nih.gov\/2020\/08\/27\/mechanics-of-the-human-walking-apparatus-1836\/","title":{"rendered":"Mechanics of the Human Walking Apparatus, 1836"},"content":{"rendered":"

By <\/em>Allison Muri ~<\/em><\/p>\n

Originally published in <\/em>

treatise on the mechanics of human motion<\/a>, a work that continued a line of inquiry that began in the seventeenth century. Rene Descartes\u2019s conception of the human as a machine animated by a soul and Giovanni Borelli\u2019s application of mechanics to anatomy in On the Motions of Animals <\/em><\/a>(1680\u201381) had helped to initiate the long debate over mechanism versus the immaterial soul and materialism versus vitalism. The suggestion that mechanics\u2014matter and motion defined by mathematically expressed laws\u2014could explain perception, thought, will, and action was politically dangerous and morally suspect. To consider the human a mere \u201cengine\u201d bordered on atheism. Borelli prudently avowed that the principal cause of movement is the soul and the active instrument is the will.<\/p>\n

At the beginning of the nineteenth century the Weber brothers also avowed that walking and running \u201cdepend on free will,\u201d but then methodically demonstrated that \u201csuch mechanical movements can be predicted by calculation,\u201d so that \u201ca voluntary act of will is not needed to move the active instruments successively in the necessary order.\u201d That the legs can oscillate like a pendulum, for instance, is a property that makes possible the regularity of successive steps. \u201cIt appears,\u201d they determined, \u201cthat the constant period of the oscillations results from the force of gravity without requiring an act of will.\u201d<\/p>\n

\"Labeled<\/a>
Imprints taken from cross sections of the skeletal foot demonstrate that the articular surfaces joining the lower leg and foot are round only in one direction, rotate almost entirely in one direction, and therefore can be considered hinges. Mechanik atlas<\/em>, pl. 11
National Library of Medicine #65260510R<\/em><\/a><\/figcaption><\/figure>\n

The Webers were the first investigators to systematically study the mechanics of human motion. To do that they needed to devise a way of capturing reliable data. Artists, they argued, had misrepresented the curvature of the spine and angle of the pelvis. The investigator seeking an accurate visualization of body mechanisms must instead use mechanical and mathematical approaches. The Webers employed the crosshairs of a telescope to measure pelvic tilt at different phases of movement, and then analyzed the phases using differential equations. To illustrate \u201cthe bases of the human walking machine\u201d they encased bones in plaster blocks and sawed them into segments to make imprints on paper. This method, they claimed, \u201cis so true that it replaces the actual specimen.\u201d A draftsman using their equations to determine the body\u2019s position at different phases of motion could illustrate running and springing figures as they might appear on a stroboscopic disk. Because the legs articulate \u201clike hinges\u201d set in a frame or the cogwheels of a watch, they obey strict rules. Such mathematically reconstructed figures can create an impression of movement \u201ccorresponding exactly to nature.\u201d<\/p>\n

\"Overlaid<\/a>
Two figures provide a model of how the motions of running and springing can be accurately drawn. Mechanik atlas<\/em>, pl. 16
National Library of Medicine #65260510R<\/em><\/a><\/figcaption><\/figure>\n

By using mechanical principles so rigorously, the Webers contributed to the ascendancy of a new materialist science of life. Increasingly, inventions such as pumps, telegraphs, combustion engines, and assembly lines would be made to serve as models of organisms and body parts\u2014and would even eventually replace or augment them. Humans and machines seemed now disconcertingly equivalent: the mechanics of living bodies subverted the idea not only of spirit enlivening the human frame but also of free will and even God.<\/p>\n

Allison Muri<\/a>,PhD, is Professor at the University of Saskatchewan. Her research interests include digital media studies and the history of cyberculture in early modern science, medicine, and technologies of communication. In <\/em>The Enlightenment Cyborg: A History of Communications and Control in the Human Machine, 1660\u20131830 she examines the history of mechanically steered, or \u201ccyber,\u201d humans in the works of seventeenth- and eighteenth-century thinkers.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

By Allison Muri ~ Originally published in Hidden Treasure: The National Library of Medicine, 2011. Few movements in a living<\/p>\n","protected":false},"author":19605840,"featured_media":19721,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false},"version":2}},"categories":[12763,51014,347145303],"tags":[273905,22379,3550,1487506,450817],"class_list":["post-19716","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-collections","category-guests","category-rare-books-journals","tag-1800s","tag-data","tag-germany","tag-hidden-treasure","tag-human-anatomy"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/circulatingnow.nlm.nih.gov\/wp-content\/uploads\/2020\/08\/HT_155_2_feature.jpg?fit=900%2C400&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p3xcDk-580","jetpack-related-posts":[],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/posts\/19716","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/users\/19605840"}],"replies":[{"embeddable":true,"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/comments?post=19716"}],"version-history":[{"count":5,"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/posts\/19716\/revisions"}],"predecessor-version":[{"id":19724,"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/posts\/19716\/revisions\/19724"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/media\/19721"}],"wp:attachment":[{"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/media?parent=19716"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/categories?post=19716"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/circulatingnow.nlm.nih.gov\/wp-json\/wp\/v2\/tags?post=19716"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}