Which control site is NOT typically used for assisting with communication devices?

The back is not typically used as a primary control site for assisting with communication devices. Communication devices, often designed for individuals with limited mobility, rely on accessible control sites that allow the user to interact with the device effectively. The thumb, head, and wrist are common and accessible areas where users can control devices using various techniques, such as switches, buttons, or sensors.

The thumb can facilitate selections on devices due to its dexterity, the head can be used for head switches or pointer systems for communication, and the wrist can also be manipulated to use devices like touch screens or switches. In contrast, the back does not provide the same level of direct access or precision for controlling communication devices, making it less suitable as a control site for these purposes. Thus, the back is not a standard choice in assistive communication technology contexts.