Ergonomics – That Mouse Can Bite You!!

If you need assistance with ergonomics as discussed in this article call us at 1-800-344-4414 or email us at for details and a free estimate.


Written by Robert E. Sheriff, MS, CIH, CSP, President and Candice Kowalewski, MPH

June 29, 2015

That Mouse Can Bite You!!


Meaning Your Computer Mouse Can Cause Carpal Tunnel Syndrome!!!

Carpal Tunnel Syndrome can have a more lasting affect than a bite from a real mouse. This is especially true if it affects your work. Sadly, it is equally as likely to get Carpal Tunnel Syndrome from work in an office as in a factory or warehouse.

By the way, where is my Carpal Tunnel, and what actually is Carpal Tunnel Syndrome?

The Carpal Tunnel is the passageway on the palm side of the wrist where all the nerves, blood vessels, ligaments, and bones pass from the arm to the hand. It controls everything in your hand but your little finger! The passageway is not all that durable and can readily be injured or inflamed.

Carpal Tunnel Syndrome is when this tunnel becomes injured or compressed. Most often, repeated compression results in inflammation which restricts blood flow and/or nerve transmission and/or ligament movement which controls wrist and finger movements.

2_Left Hand        3_Right Hand

Picture(s) source: A patient’s guide to Carpal Tunnel Syndrome

It’s easy to get Carpal Tunnel Syndrome, because the wrist is much less mobile that you might have guessed. First of all, it is not to be used as a resting place. Place your hand flat on a surface. Your wrist should not be touching the surface. Also, the wrist has only one intended movement, downward! Your wrist has very little ability to move sideways or up (back that is). That’s why it’s hard to do push-ups! Your wrist isn’t supposed to be bent back that far! Side to side movement is done primarily from the elbow, as well as rotational movements.


4_Center Mouse and Hand

Using the palm side of your wrist as a support, such as in the use of a mouse, over a lengthy period of time can result in irritation, inflammation, swelling, and pain in the wrist. Supporting the mouse with a wrist pad (however soft) is not appropriate since it will compress your Carpal Tunnel and the surrounding nerves, vessels, and ligaments.

Of course, using your wrist as a pounding or pushing device will almost certainly lead to Carpal Tunnel Syndrome eventually. Shuffling papers, using a computer mouse, using scissors, pushing product on an assembly line, welding on metal parts, rapidly sorting, packaging small items, even heavy use of a musical instrument like a piano can all lead to the same end,–tingling in the fingers, numbness of parts of the hand or fingers, pain in the hand or wrist that does not go away with a day’s rest or a couple of pills. The following table lists common tasks and related occupations associated with carpal tunnel syndrome.


 Job tasks and occupations associated with carpal tunnel syndrome 

Job Tasks


Lifting freight, stock, and material Laborers
Grasping and tugging fabric, pulling cloth Production sewer, tailor, garment worker/stitcher
Milking cows Farmers
Handling objects on conveyor belts Assembly-line workers
Pushing down ratchet, using screwdriver Automotive technicians and mechanics
Hand weeding Gardeners
Using spray gun Painters
Knitting Homemakers
Scrubbing Janitor, maids, house cleaners
Playing stringed instruments with bow Musicians
Using laser scanner at checkout Cashiers
Cutting, de-boning Butcher/poultry-processing workers
Assembling small parts Electronic industry workers
Turning keys Locksmiths
Wearing poorly fitting gloves which apply external pressure Agricultural worker, mechanic, factory workers
Pressing tool into palm Painters, carpenters, stable hand, welders, cutters, solderers, brazers, sheet metal workers
Pounding safety level or stamping machine Receipt processors
Using air-powered hand tools Assembly workers
Flexing or extending the wrist while kneading dough Bakers



There are things you can do if your job entails heavy computer and computer mouse work. Cornell University’s Ergonomic website has “10 Tips for Using a Computer Mouse” that is excellent and some surprising suggestions on preventing Carpal Tunnel Syndrome.

Very often arthritis is believed to be the cause when it’s not. “Oh, I just have a little arthritis in my fingers—that’s all!”

How you can distinguish between “a little arthritis” from Carpal Tunnel Syndrome?

A good summary of symptoms especially if you regularly repeat a task involving the hand/wrist can be found at the Web MD website. Briefly they state these signs of Carpal Tunnel Syndrome:

-Tingling, numbness, pain in the hand, forearm or wrist—especially if it wakes you up at night (or whenever you sleep!)

-Pain gets worse while using the hand or wrist or tightly gripping an object.

-Pain in the arm or elbow.

-Stiffness in fingers when you wake up in the morning (or whenever you wake up).

-Loss of strength when trying to pinch an object.

-Dropping objects when using a tool or even personal objects (such as a hair brush or screwdriver).

-If the symptoms extend to your little finger, then it is likely arthritis not Carpal Tunnel Syndrome (remember that little finger nerves don’t go through that part of the wrist).

Here is some bad news! There are a variety of lifestyle items that can increase your risk of developing a musculoskeletal disease (MSD) such as Carpal Tunnel Syndrome. They include use of tobacco, caffeine, and alcohol. You can find the details in an article in the Journal of Occupational and Environmental Medicine, March 1996, Volume 38, No. 3, pages 290-298 titled, “Tobacco, Caffeine, Alcohol and Carpal Tunnel Syndrome in American Industry, A Cross-Sectional Study of 1464 Workers,” by P.A. Nathan, R.C. Keristan, et. al.

Carpal tunnel syndrome is also associated with several diseases and situations. They are:

  • Arthritis
  • Diabetes
  • Gout
  • Amyloidosis (infiltration of the liver, kidneys, spleen with a starch-like substance)
  • Hypothyroidism (underactive thyroid gland)
  • Tumors of tendon sheaths
  • Wrist fractures and dislocations
  • Wrist cysts
  • Pregnancy
  • Use of oral contraceptives
  • Menopause

All these diseases and situations increase the volume of the contents of the carpal tunnel, resulting in compression of the median nerve. Also some individual factors, such as the size and shape of the wrist and the shape of the median nerve, may contribute to the development of carpal tunnel syndrome.

The final thing is what are the cures for Carpal Tunnel Syndrome? (The first is a don’t!)

  •  Don’t use a splint while performing the task that caused the problem. The splint will just put more pressure on the wrist!
  •  Use a splint at night when you are not performing the causative task!
  •  Anti-inflammatory medications should only be used with a physician’s advice.
  •  Follow Cornell University’s guidance on using a mouse.
  •  Add rest periods in your activity regimen.
  •  Use the bigger muscle of the arm and shoulder to take some of the weight.
  •  Warm-up stretching and regular exercise to maintain muscle health.
  •  Avoid lifestyle activities that increase your risk of CTS such as smoking, drugs (legal and illegal), alcohol.

Assessing a workplace or work activity for its potential to cause Carpal Tunnel Syndrome is a task for an ergonomist or an Industrial Hygienist with the objective of preventing this condition. Also these professionals can investigate an activity that has caused Carpal Tunnel Syndrome and suggest ways to modify the worksite, or the motions required to perform the task and suggest ways to eliminate the source of the problem.

If you are experiencing symptoms of Carpal Tunnel Syndrome, don’t blame your mouse too much, he may be the innocent party here. For more information, or professional help contact us at 1-800-344-4414 or at

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