Trackballs are stationary input devices that use a small, rolling ball to move the cursor operated by your thumb or fingers. You may want to consider a trackball if you are experiencing shoulder pain, as it lets you move the cursor while keeping your arm in a fixed position. The other advantage to a trackball is they take up less desk space than a mouse and many trackballs are programmable with multiple buttons that can be assigned keystrokes to help reduce keyboard use. Ergo Works offers a selection of symmetrical, asymmetrical, corded and cordless trackballs to choose from.