There are so many different designs of computer mice available, yet researchers have not yet discovered what design best helps prevent injuries. Although employees should be allowed to try different models and see which suits their needs, we have some tips that may be helpful:

• A battery-powered cordless mouse is highly recommended, because there is no cord to get in the way.
• Shape:
  • Choose a mouse that fits your hand. Many people find the "teardrop" shape comfortable.

Figure 1

• Choose a flat shaped mouse, which reduces wrist extension.
• Choose a mouse that is shaped the same on both sides.
• Avoid a curved mouse.
• Size:
  • Choose a mouse that is large enough to support the natural curve of your hand.

A larger mouse that still fits in the palm of your hand helps you use your larger arm muscles rather than the smaller wrist muscles, which tire easily and are more likely to experience Workplace Musculoskeletal Disorders (WMSDs).

• Buttons:
  • Choose a mouse with buttons that respond to a light touch, so that you don't have to press too hard to make it work, but one that isn't so sensitive that you hardly have to press it to activate it.
  • Choose a mouse with buttons that neither cramps the fingers nor spreads them out too far apart.
  • Choose a mouse with a "drag lock" or "click lock" function.

A well-designed workstation with a properly selected computer mouse helps prevent discomfort and injury. By following the suggestions below, which tell you the safest way to use the mouse, you can further prevent such problems.

• Don't squeeze the mouse. Hold it loosely in your hand with a relaxed grip. A tight grip will not help you position the pointer any better or faster.
• Keep your wrist straight. Your forearm, wrist, and fingers should all be in a straight line (Figure 2).

• Protect your wrist - do NOT use a wrist-rest. Using a wrist-rest puts more pressure on the carpal tunnel in your wrist, which can cause painful Carpal Tunnel Syndrome (CTS). Using a wrist-rest also restricts the flow of blood to and from your hand.
• Keep the mouse clean. If the mouse becomes jumpy or less sensitive, the problem may be a build-up of dust on the rollers.
• Alternate the hand using the mouse, if possible.
• Use the shortcut and function keys on the keyboard instead of the mouse whenever possible.