¶ Introduction
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¶ Keyboards
Typing will become difficult as the intrinsic muscles in the hand weaken. Hunt-and-peck will remain possible as long as the arms are able to be lifted up such that the hands can be held above the keyboard.
Keyboards which have tall buttons are the easiest to use for hunt-and-peck. The tops of the keys can catch the fingernail which simplifies indexing on the key cap.
¶ Re-mapping keys
Key combinations, such as using the shift key along with a letter, or control-alt-delete are the most difficult keyboard tasks. Key mapping software can be used to map frequent combinations to simpler ones. Rarely-used keys can be sacrificed for this purpose, or if the key mapping software supports it, a second keyboard could be provisioned.
¶ Key Mapping Software
- macOS: Karabiner Elements
- Windows: AutoHotKey
¶ On-screen keyboards and hardware alternatives
An alternate input device will be required once hand and upper limb weakness have reached a point where it is no longer possible to hold the hands above the keyboard. Such devices include:
- On-screen keyboards operated using a pointing device, such as a mouse.
- Proprietary hardware keyboards designed for people with disabilities.
On-screen keyboards can be quite tedious to use due to the amount of clicking required. To streamline the process, frequently entered text—like names or addresses—can be added as custom buttons. Additionally, common key combinations such as cut, copy, and paste are excellent options for assignment to these custom buttons.
¶ Mice
Using a mouse becomes increasingly challenging as muscle weakness and atrophy in the hand worsen. While the specific sequence of difficulties experienced can vary from person to person, the following provides a general estimate from earliest onset to latest:
- Accessory buttons operated by the thumb become harder to press.
- Operating a scroll wheel with the middle finger becomes more difficult.
- Double-clicking sufficiently quickly becomes more difficult.
- Clicking with the index finger becomes more difficult.
- Placing the hand on the mouse without accidentally clicking a button becomes more difficult.
- Clicking the mouse without also causing a small amount of movement becomes more difficult. The user interface may interpret this as a dragging operation instead of a click.
¶ Adaptations
Purchasing adaptive pointing devices can potentially be avoided for a very long time by making the following adaptations:
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Difficulty clicking the primary button with the index finger can be mitigated by flipping the role of the buttons on the mouse, and instead using the middle and ring finger as a primary click. It is possible to get used to this change within a few hours.
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Difficulty double clicking quickly enough can be mitigated by increasing the double click time interval in the operating system's pointing device settings.
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Accidental clicks when placing the hand on the mouse can be mitigated by moving the mouse to a region of the screen where the accidental click will have no consequences.
¶ Using only one mouse button
Users can replicate middle click, and right click functionality using a modifier key coupled with the primary click in the following manner:
macOS:
Middle-click: ⌘ + primary click
Right-click: control + primary click
Windows:
Middle-click: control + primary click
Right-click: shift + primary click
¶ Trackballs
Trackballs will be difficult for anyone that has mobility issues with their thumbs. With ALS, such issues are often one of the earliest symptoms.
Trackballs are likely to be of limited use to someone with ALS.
¶ Adaptive Devices
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¶ Voice Dictation
Voice dictation can be used in place of a hardware input device for typing. Its use requires relatively clear speech to work well.