Prediction of trapezius muscle activity and shoulder, head, neck, and torso postures during computer use: results of a field study

Background: Due to difficulties in performing direct measurements as an exposure assessment technique, evidence supporting an association between physical exposures such as neck and shoulder muscle activities and postures and musculoskeletal disorders during computer use is limited. Alternative exposure assessment techniques are needed. Methods: We predicted the median and range of amplitude (90th-10th percentiles) of trapezius muscle activity and the median and range of motion (90th-10th percentiles) of shoulder, head, neck, and torso postures based on two sets of parameters: the distribution of keyboard/mouse/idle activities only (“task-based” predictions), and a comprehensive set of task, questionnaire, workstation, and anthropometric parameters (“expanded model” predictions). We compared the task-based and expanded model predictions based on R2 values, root mean squared (RMS) errors, and relative RMS errors calculated compared to direct measurements. Results: The expanded model predictions of the median and range of amplitude of trapezius muscle activity had consistently better R2 values (range 0.40-0.55 compared to 0.00-0.06), RMS errors (range 2-3%MVC compared to 3-4%MVC), and relative RMS errors (range 10-14%MVC compared to 16-19%MVC) than the task-based predictions. The expanded model predictions of the median and range of amplitude of postures also had consistently better R2 values (range 0.22-0.58 compared to 0.00-0.35), RMS errors (range 2–14 degrees compared to 3–22 degrees), and relative RMS errors (range 9–21 degrees compared to 13–42 degrees) than the task-based predictions. Conclusions: The variation in physical exposures across users performing the same task is large, especially in comparison to the variation across tasks. Thus, expanded model predictions of physical exposures during computer use should be used rather than task-based predictions to improve exposure assessment for future epidemiological studies. Clinically, this finding also indicates that computer users will have differences in their physical exposures even when performing the same tasks

Security that matters: critical infrastructure and objects of protection

Critical infrastructure protection is prominently concerned with objects that appear indispensable for the functioning of social and political life. However, the analysis of material objects in discussions of critical infrastructure protection has remained largely within the remit of managerial responses, which see matter as simply passive, a blank slate. In security studies, critical approaches have focused on social and cultural values, forms of life, technologies of risk or structures of neoliberal globalization. This article engages with the role of "things" or of materiality for theories of securitization. Drawing on the materialist feminism of Karen Barad, it shows how critical infrastructure in Europe neither is an empty receptacle of discourse nor has "essential" characteristics; rather, it emerges out of material-discursive practices. Understanding the securitization of critical infrastructure protection as a process of materialization allows for a reconceptualization of how security matters and its effects

Vocal Culture in the Age of Laryngoscopy

For several months beginning in 1884, readers of Life, Science, Health, the Atlantic Monthly and similar magazines would have encountered half-page advertisements for a newly patented medical device called the ‘ammoniaphone’ (Figure 2.1). Invented and promoted by a Scottish doctor named Carter Moffat and endorsed by the soprano Adelina Patti, British Prime Minister William Gladstone and the Princess of Wales, the ammoniaphone promised a miraculous transformation in the voices of its users. It was recommended for ‘vocalists, clergymen, public speakers, parliamentary men, readers, reciters, lecturers, leaders of psalmody, schoolmasters, amateurs, church choirs, barristers, and all persons who have to use their voices professionally, or who desire to greatly improve their speaking or singing tones’. Some estimates indicated that Moffat sold upwards of 30,000 units, yet the ammoniaphone was a flash in the pan as far as such things go, fading from public view after 1886

Opera and Hypnosis: Victor Maurel’s Experiments with Verdi’s Otello

One day in his private home on the avenue Bugeaud, in Paris’s sixteenth arrondissement, the famous baritone Victor Maurel hosted a meeting which combined music with hypnotism of a young woman

Unsound Seeds

With this image of a curtain hiding and at the same time heightening some terrible secret, Max Kalbeck began his review of the first Viennese performance of Richard Strauss’s Salome. Theodor W. Adorno picked up the image of the curtain in the context of Strauss’s fabled skill at composing non-musical events, when he identified the opening flourish of Strauss’s Salome as the swooshing sound of the rising curtain. If this is so, the succès de scandale of the opera was achieved, in more than one sense, as soon as the curtain rose at Dresden’s Semperoper on 10 December 1905. Critics of the premiere noted that the opera set ‘boundless wildness and degeneration to music’; it brought ‘high decadence’ onto the operatic stage; a ‘composition of hysteria’, reflecting the ‘disease of our time’, Salome is ‘hardly music any more’.The outrage did not end there

Science, Technology and Love in Late Eighteenth-Century Opera

It is a tale told by countless operas: young love, thwarted by an old man’s financially motivated marriage plans, triumphs in the end thanks to a deception that tricks the old man into blessing the young lovers’ union. Always a doddering fool, the old man is often also an enthusiast for knowledge. Such is the case, for instance, in Carlo Goldoni’s comic opera libretto Il mondo della luna (1750), in which Buonafede’s interest in the moon opens him to an elaborate hoax that has him believe he and his daughters have left Earth for the lunar world; and also in the Singspiel Die Luftbälle, oder der Liebhaber à la Montgolfier (1788), wherein the apothecary Wurm trades Sophie, the ward he intended to marry himself, for a technological innovation that will make him a pioneering aeronaut

Operatic Fantasies in Early Nineteenth-Century Psychiatry

In his celebrated essay on insanity in the Dictionnaire des sciences médicales (1816), French psychiatrist Étienne Esquirol marvelled at the earlier custom of allowing asylum inmates to attend theatrical productions at Charenton