If you want full freedom of movement, you should opt for a wireless mouse such as this one. This is a slightly more advanced mouse with as many as seven buttons.
From OnBuy
perixx PERIMICE-717 Wireless Trackball Mouse, Build-in 1.34 Inch Trackball with Pointing Feature, 5 Programmable Buttons, 2 DPI Level, 11568
Conrad Electronic
Perixx PERIMICE-717 D Trackball Radio Laser Black 7 Buttons 2000 dpi Ergonomic, Built-in trackball