A Roller ball, also sometimes known as a trackball, provides a mouse alternative that is operated by the user moving a ball to control the pointer movement. Left and right click operations are provided for by buttons with an additional button (in most models) for drag lock to allow for easy single handed operation.
For more advance computer control and for users with more severe motor problems some models have additional buttons providing easy speed control and direction lock.
Accidental button presses are reduced by having recessed buttons and in addition some roller balls and trackballs have keyguards and extra sockets to allow external switches to be used as alternatives to the built-in buttons.
Wireless roller balls and joysticks allow the user to choose the best position for operation and give them more independence.
These devices operate in the same way as a standard mouse so they do not require any additional software, simply connect to a USB socket and they can be used at the same time as a standard mouse.
Inclusive Technology also supply angled Rollerball rests to give further positioning options.