Level AWCAG 2.2

2.5.4 Motion Actuation

Functionality operated by device motion or user motion can be operated by user interface components.

Why it matters

Wheelchair-mounted devices
When the device is fixed in place, shaking or tilting is physically impossible.
Motor impairments
Shaking the device is difficult or dangerous for many users with motor impairments.
Involuntary movement
Tremors and spasms cause unintended motion that can accidentally trigger shake gestures.
User control
A setting to disable motion-based activation respects every user's autonomy.

Live demo

Motion actuation

Only 'shake to undo' is available, so users who cannot shake the device cannot use the feature.

Text editor

Hello, world!
Relies only on device motion with no button alternative

Understanding through personas

Inoue (30) — Spinal cord injury

I have my tablet mounted on my wheelchair. 'Shake to undo' isn't possible for me, so on-screen buttons are my only option. Apps without them force me to give up that feature.

Checkpoints

References