To enable navigation without a mouse, you need to turn on the high-contrast color
scheme in your Preferences settings.
To turn on the high-contrast color scheme:
Go to Your avatar > Preferences to open the Preferences page.
Click General Preferences.
At the bottom of the page, click On in the high-contrast
color scheme field.
If you are using a Mac OSX environment, you also need to turn on all "All
controls" for full keyboard access by navigating to System Preferences > Keyboard > Shortcuts and select All options at the bottom of
If you are using Mac OSX, you can enable voiceover capability by navigating to System Preferences > Shortcuts > Accessibility and select Turn VoiceOver on or off.