Benefits of a trackball mouse:
- May help with arthritis of the hand / fingers because it keeps the hand and fingers moving
- Allows you to avoid grasping which can reduce hand cramping or muscle spasm
- Can reduce incidence of tendinitis of the index or middle fingers
A trackball mouse frees you from having to actually grip or hold the mouse during use and the mouse casing stays in one position on the desktop. Rather than move the mouse around the desktop to move the cursor, like you would with a standard mouse, you move the cursor by rolling a ball housed within the mouse casing. The primary reason for using a trackball mouse would be to free the user from having to continuously grasp the mouse. This is particularly beneficial if you are suffering with hand cramping from prolonged gripping, or arthritis in the hand and fingers. For arthritis in particular, use of a trackball mouse can actually be therapeutic as the trackball mouse requires the user to move the hand and fingers a lot during use, as opposed to use of a standard mouse which requires very little movement of the hand and fingers (with a standard mouse the movement comes more from the wrist and arm to move the mouse whereas the hand itself does not move much at all). Movement is the best thing for arthritic joints, which is why use of a trackball mouse is generally a good option for anyone suffering with arthritis in the hand or fingers. Of the trackball mice I have used, the Kensington Orbit mouse feels the most natural in terms of size and shape, and the layout is simple yet logical. The trackball, which controls the cursor, is a good size and feels solid and responsive in my hand. The scroll wheel is smartly positioned as a ring around the trackball, which at first I thought would be difficult to use but I quickly discovered that it actually felt quite natural when using it in the same way you might turn a dial - use of the thumb to rotate counter-clockwise, and use of the ring and pinky fingers to rotate clockwise. As noted above, the best thing about using this mouse is that your hand and fingers are very mobile when moving the trackball and scroll wheel. As anyone with arthritis can attest to, keeping arthritic joints moving can help with symptoms of joint stiffness. In addition, when your hand is idle on the mouse (i.e. those moments between mouse actions when your hand isn't really doing anything) your hand is in a loose resting position over the top of the moue as opposed to a standard mouse where the hand is in a constant grip-like position. Keeping the hand loose and open may reduce the incidence of cramping or muscle spasm in the hand.
Another good reason to switch to a mouse like the Kensington Orbit trackball mouse is if there is tendinitis of the index or middle finger. Tendinitis of these fingers may occur as a result of the small repetitive movements required from constant clicking of the left and right mouse buttons on a standard mouse (which for most people are operated by the index and middle finger, respectively). The Kensington Orbit trackball mouse requires the user to use the thumb for left button functions and the ring and / or pinky fingers for right mouse button functions, thus freeing up the index and middle fingers from being used for left and right mouse click functions.
The Kensington Orbit trackball mouse has the trackball centrally positioned, whereas some trackball mice will have the trackball optimized for use with the thumb. I generally do not recommend the type of trackball mouse that requires the thumb to operate the trackball. When using a thumb trackball mouse the hand tends to remain quite static and most of the movement comes only from the thumb. Continuous circumduction of the thumb (the circular movement required to operate this type of trackball) significantly increases the risk of tendinitis of the thumb. For that reason, if you are considering using a trackball mouse other than the Kensington Orbit, of which there are many fine options, I would advise that you avoid a thumb trackball mouse and choose a central trackball mouse.