Human-Computer Interaction: Ergonomics and User Interfaces - Vol. 1

By Hans-Jörg Bullinger; Jürgen Ziegler | Go to book overview

Performance and Muscle Load among Young
and Elderly

Laursen B., Jensen B.R., Ratkevicius A.*
Department of Physiology, National Institute of Occupational Health,
Copenhagen, Denmark

*NMR-center, Panum Institute, University of Copenhagen, Copenhagen,
Denmark


1
Introduction

The share of elderly employees is rising. Age-related changes in physical capacity ( Ilmarinen et al; 1991) and muscle function ( Kinoshita and Francis, 1996) may influence the workload when the work demands remain unchanged. This might increase the risk of developing work-related symptoms and pain in the musculoskeletal system. Some of the age-related physiological changes could be important in computer work, especially those concerning the ability to perform precision work. The aim of the present study was to test for age-related differences in working speed and muscle activation patterns when performing computer work.


2
Methods

Eight young (25 years, range 22-28 years) and nine elderly (63 years, range 5670 years) experienced female computer users participated in the study. The subjects performed computer work at a height-adjustable desk with forearms supported. During a 4-hour period, the subjects performed a computer mouse test, consisting of 11 tasks, five times. These tests were based on an ISO standard (ISO 9241, 1994). Six tasks consisted of clicking multidirectional targets of different width (8, 16, 32 pixels, corresponding to 2.5, 5, and 10 mim on the screen and approximately 0.3, 0.6, and 1.2 mim for the mouse) in a selfdetermined speed and a predefined speed (40 mim-1). A circle was traced in a predefined speed (1 rev / 8 s). The remaining tasks were horizontal and vertical (relative to the computer screen) clicking a 16-pixel wide target, double clicking (40 min-1), and dragging (20 mill-1). For each task, the error rate (failing/attempted operations) and working speed (successful operations · min-1)

-89-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this book

This book has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this book

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited page

Bookmark this page
Human-Computer Interaction: Ergonomics and User Interfaces - Vol. 1
Table of contents

Table of contents

Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
/ 1356

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.