Page 137 - Handbook of Electronic Assistive Technology

Chapter 5 • Alternative Access Technologies 125

Keyboard Shortcuts and Macros

Another alternative to the mouse is to use the keyboard; this can give almost complete
access to a computer. Many of the menus and functions in software and apps running on
operating systems offer keyboard shortcuts; instead of using the mouse to pull down the
menu and select the item, you can press a combination of keys. Examples of keyboard
shortcuts are Open File (CTRL + O), Copy (CTRL + C), and Paste (CTRL + V). Keyboard
shortcuts can increase efficiency and comfort for all users.
Users who type with a headpointer or mouthstick, or who require a keyguard, will
almost certainly have difficulty with mouse control. Users who cannot hold down two keys
at once can press them sequentially using Sticky Keys.
• Windows keyboard shortcuts. 17
• MacOS keyboard shortcuts. 18
• iOS hardware keyboard shortcuts. 19
Trackballs

With a trackball or rollerball you move a ball with your fingers (or foot, nose, elbow, etc.)
and the mouse pointer moves correspondingly. Trackballs may be suitable for people:
• Who cannot grasp or move a mouse, but who have good dexterity with hand and
fingers.
• Who suffer pain or fatigue when moving the mouse (due to RSI or arthritis, for example) –
with a trackball less movement of the hand, wrist and arm is required.
• Who have poor fine motor control – people with uncontrollable movements and tremor
usually find trackballs easier to control than mice.
• Who have limited workspace – for example, who use a small wheelchair tray.

Trackballs vary in diameter from between 35 and 75 mm (Fig. 5-14). Smaller balls are
more sensitive – the arc of movement required to move the mouse pointer a given distance
on screen is smaller than that for a larger ball – and so smaller trackballs require greater
dexterity. It is, however, also possible to reduce the mouse speed, which then requires the
user to spin the ball further. Some trackballs are shaped to fit the hand, or have wrist and
palm rests.
There are many different types of trackball available from mainstream technology sup-
pliers and specialist assistive technology providers. Most trackballs are supplied with soft-
ware for adjusting the response and for programming buttons (e.g., to drag or to double
click when a button is pressed once). If you want a trackball and you do not need a button
guard it is worth exploring the mainstream devices because they are programmable and
often less expensive than the specialist trackballs.

17 https://support.microsoft.com/en-us/help/12445/windows-keyboard-shortcuts.
18 https://support.apple.com/en-gb/HT201236.
19 https://support.apple.com/kb/PH23094?viewlocale=en_AU&locale=en_AU.