CAN MICE MAIM?
Cindy Burt, MS, OTR

The introduction of Windows software has resulted in a dramatic increase in the use of pointing devices such as mice and trackballs. Computer operators have reported increased upper extremity discomfort after using these devices for extended periods of time. This article will assist you in determining whether your discomfort is related to use of a pointing device and what to do about it.

How do you determine if your discomfort is related to use of a pointing device? The most obvious indicator would be a unilateral problem. A unilateral injury affects only one arm or hand. Pain, discomfort, fatigue or soreness would be related to the hand operating the pointing device. If you have pain in one hand, look at activities you are completing with that hand. Causes could include the pointing device, use of the numeric keypad, the cursor arrow keys, the function keys, the space bar, escape or other editing keys.

What do you do if you are having problems? Ignoring pain, symptoms or warning signals may complicate an injury and lengthen recovery time. Computer-related problems are much easier to treat in the early phases. Monitor your situation. Infrequent discomfort that goes away overnight is most likely fatigue. Reoccurring pain that lingers could be a sign of something serious. Seek medical treatment if you are experiencing frequent, lingering pain and discomfort in your arms and/or hands.

Make sure your treating physician is familiar with work-related repetitive motion injuries. General physicians may not have the experience and training required to treat overuse problems. Your doctor may refer you to see an occupational or hand therapist for treatment and training. Therapy could include massage, stretching activities, and education on body mechanics, positioning, and proper use of equipment. Therapy may take from a few weeks to several months depending on the severity of the injury and flare-ups.

The most important change you can make could be to your work area. However, what is right for one person, may not be right for another. If you make changes and feel better, you are probably on the right track. Below are some possible solutions to reduce or eliminate pain related to pointing device use.

• Limit the use of the mouse or trackball if possible. The best remedy for a pointing device injury is rest to the affected limb or area.
• If you are experiencing shoulder or neck pain, evaluate your posture and work station height. It may be too high or low. Your workstation should be approximately at elbow level with your arms relaxed at your side.
• Repetitive movement of the upper arm associated with pointing device can result in shoulder pain. Use of a trackball can reduce this problem. A trackball reduces the need to complete upper arm movements by utilizing the smaller forearm muscles. However, use of these muscles could result in forearm pain. Start gradually and build up your tolerance to use these smaller muscles. Be aware of your wrist position when using the trackball. Avoid excessive wrist extension by attempting to keep your wrist in a neutral position with the use of a pad placed in front of the trackball. Finally, avoid overuse of the thumb. Do not purchase a trackball that uses the thumb to roll the ball.
• If your work requires repeated button clicking, try using a trackball with a foot pedal or device that requires less force to activate. The Kraft Trackball (619/724-7146) and the Curtis Trackball (800/955-5544) are available with foot pedal options to reduce the load on the fingers. The Microsoft Mouse (206/882-8080) has low button activation force and is available for PC users.
• Drag-lock features are available on most trackballs. This option allows you to click on an object and hold without depressing the button. The held object can be released when a second click is executed. Logitech (800/231-7717) has a mouse with drag-lock capability. However, the Logitech is large in size, and requires high activation forces. MAC users can use a $3 MAC Shareware program.
• Soreness in the ring or little finger may result from a pointing device that is too large or too small for you. Evaluate your hand size in relation to the device. The device should fit comfortably with the palm of your hand in a neutral position.
• Avoid prolonged holding of the pointing device. If you are not using the pointing device, let it go.
• Elbow soreness can result from poor posture or positioning. Make sure your workstation is properly set up. Repeated extension of the fingers or constantly holding the fingers suspended over your pointing device can aggravate the tendons at the elbow. Try to rest your fingers gently on the device surface.
• Use of a pen stylus can aggravate your tendons. Try switching to a puck stylus to use different muscles. Switching periodically could help on a long term basis.
• A last alternative may involve switching hands. Do this with caution, gradually building up strength and endurance. Be aware that switching hands may result in pain or discomfort in the other hand.

It is important that you take a break from working at your computer every 20 to 30 minutes. Repetitious work at a computer is fatiguing to your arms as well as your eyes. Your body needs periodic breaks to rest and recover. Move around and complete other tasks that allow you to change positions.

Increasing work demands often lead people to ignore pain and discomfort. Be aware of your body, and take preventive measures to increase your comfort level. If you have any questions about using a pointing device, contact your injury prevention specialist. Occupational therapists are available to assist you in evaluating your work station needs.