Dr. Mark Humphrys

School of Computing. Dublin City University.

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RSI - A Lecture

RSI - Repetitive Strain Injury.

Many people using computers for a long time develop pains in their fingers or wrists. Nothing strange about this - You have the same in any area that demands repetitive, precision movements - knitting, writers cramp. The condition is actually very old.

Just to be aware that you are at high risk of this happening to you. Things you can do to prevent it developing:

Cut down on hand actions

  1. Reduce the number of mouse movements. Learn keyboard shortcuts. These are normally all listed in the menus. e.g.:
    • In browsers, Ctrl-N or Shift-Click to open new window.
    • In Windows, Alt-Tab to jump to last window, Win-m to minimise all windows.
    • In UNIX, experiment with different windowed environments. Get Windows-like list of processes in a bar along the bottom or side. Redefine key to raise/lower, maximise/restore window.

  2. Reduce the number of things you have to type.
    • Cut and paste URLs and code and data. Never type anything twice (or even once). Never tell people anything twice (or even once). Send them URLs instead.
    • Use macros in editing. Use assisted editors for HTML, programming languages.
    • Use command-line history in UNIX. Use wildcards for filenames. Use filename completion.
    • Write Shell files to automate common tasks.
    • In Windows, make shortcuts to frequently used programs.

  3. Avoid double-click and drag with the mouse. These, more than anything else, are the things that cause damage to people's hands.

  4. Don't play games. You need your hands for your career. Don't sacrifice them to:
    1. games (play sport instead)
    2. chat (meet people instead)
    3. instant messaging (meet people instead)
    4. texting (ring people instead)
    5. online shopping (maybe go to the shops instead)
    6. small devices - mobile phones / PDAs / iPods / music players (maybe do it on a PC instead)
    or other things with tiny buttons or intensive real-time activity.

  5. Basically, figure out what you absolutely need to do on a machine and maybe do some of the other things "in real life" to give your hands a break.

  6. Possibly - Don't learn how to type.

Of course, like everyone else (including me), you will ignore all advice about possible problems until there is at least some indication that you have the problem.

Click the mouse with the keyboard

  1. Windows:
    • Control Panel - Accessibility Options
    • Keyboard - StickyKeys
    • Mouse - MouseKeys (also here) uses numeric keypad instead of mouse. NumLock to turn it on/off.
      click: 5
      double click: +
      start drag: 0
      end drag: .
      right-click: -

  2. Linux (depending on distribution):
    • Settings - Universal access - Mouse Keys
    • Computer - Control Center - Keyboard - Mouse Keys
    • Then can click with numeric keypad as above.

  3. UNIX:
    • XAccess

  4. Using Perfect Keyboard, I program my keyboard so that:
    F1 is single click <mlbd><mlbu>
    F2 is double click <m2click>
    F3 is right click <mrbd><mrbu>
    F7 is drag start <mlbd>
    F8 is drag end <mlbu>
    and I never, ever, have to click the mouse. I just move it with my right hand, click the keyboard with my left.
    I also have things like:
    F5 is Alt-Tab <alt><tab><alt>
    F9 is Alt-Left (back in browser)
    F10 is Alt-Right
    F11 is shift-click (open web page in new window)


ancientbrain.com      w2mind.org      humphrysfamilytree.com

On the Internet since 1987.

Wikipedia: Sometimes I link to Wikipedia. I have written something In defence of Wikipedia. It is often a useful starting point but you cannot trust it. Linking to it is like linking to a Google search. A starting point, not a destination. I automatically highlight in red all links to Wikipedia and Google search and other possibly-unreliable user-generated content.