Wednesday, December 17, 2008

Mouse Rest

The wrist rest is probably the most widely used and misunderstood piece of ergonomic equipment available. 

Placing a wrist rest in front of the keyboard has become synonymous with providing ergonomic adjustments to a work area. 

  • When an ergonomic assessment is required, the very first item that is often checked off on the ergonomic modification checklist is provision of the wrist rest. 
  • When clients tell me that they have made ergonomic changes to their computer desk, they often mean that they have purchased a wrist rest.


The Concept is Good, But….

My problem with the wrist rest is not with the concept.  Wrist rests can play an important role in wrist positioning for those using a keyboard or mouse.  The goal is to have a neutral wrist (the wrist being flat and straight, not bent forward or back or angled to either side).  A neutral wrist angle reduces stress and friction on the structures at the wrist and can help reduce discomfort and fatigue with typing and mousing activities.

However, I do have two issues with the wrist rest.  The first is in the name and the second is in the training (or lack of) for its use.

Purpose – Guide and Glide

In spite of the misleading name, the wrist rest is not designed for resting the wrist while typing.  The wrist rest should guide the wrist into a neutral position enabling the wrist to glide over the wrist rest while typing.  The wrist should only actually touch down on the wrist rest during typing breaks. If the wrists are actually planted down on the wrist rest during typing, the small finger muscles are isolated causing awkward finger positioning and movements and creating muscular stress. 

 Proper Wrist Rest Use

When typing, the wrists should be in a neutral position.  They should float over the wrist rest and hand placement for key reach should be initiated through the shoulder and elbow. 

See Neutral Position – Fingers, Wrist & Forearm

See Typing Style – Repetitive Strain Injuries are NOT Just About the Keyboard

Similarly, a wrist rest in front of a mouse causes the mouse to be activated by swiveling the wrist.  This can lead to repetitive strain injuries and tendinitis.  As with the keyboard, mouse movement should be initiated through small shoulder and elbow movements while the wrist is held in the neutral position.

See Pain-Free Mousing

The Bottom Line

Those who are responsible for providing ergonomic modifications to work stations should be aware of the proper function and use of the wrist rest.  They need to provide the appropriate training if they issue a wrist rest.  Otherwise, those who do not know better will revert to the function of this poorly named ergonomic piece of equipment and rest their wrists while typing - potentially increasing their work injury risk.

Marji Hajic is an Occupational Therapist and a Certified Hand Therapist practicing in Santa Barbara, California. For more information on hand and upper extremity injuries, prevention and recovery, visit Hand Health Resources.

Labels: , ,

Wednesday, December 10, 2008

Female and Fashionable

Women develop carpal tunnel syndrome, tendinitis and other repetitive strain injuries about twice as often as men.  Hormonal shifts, fluid retention, pregnancy, and menopause are known to increase the incidence of risk for repetitive strain injuries.  Also, women are typically smaller than men.  Smaller bones and muscles need to work harder to perform the same job increasing the risk of muscular fatigue and strain.  As women work with tools that are typically designed for larger bodies, they may be working on equipment that is too high or too heavy, causing the female body to work in awkward positions or perform forceful muscular exertions (two of the risk factors for developing a repetitive strain injury).

These are issues that we need to be aware of but may not be able to impact to a large degree.  However, the following two tips for female fashion divas are things that we as women can do to immediately reduce our risk of injury from repetitive strain.

Long Fingernails

Women typically have longer fingernails than men.  When fingernails are longer, typing style is affected.  The least stressful position for typing is with the fingers relaxed and slightly rounded - as if the hand is resting over a large ball. 

Typing should be performed by tapping the tip of the finger against the key using the least force necessary to activate the key. The longer the fingernail, the flatter the finger needs to be on the keyboard so that the pulp of the finger is hitting the key rather than the tip of the finger.  This places stress on the smaller muscles of the hand that run between the bones of the finger.  This also places stress on the muscles on the outside of the forearm. 

If you are experiencing pain in the forearm or the outside of the elbow, try trimming those fingernails and type with the hand in as relaxed a position as possible using the tips of the finger rather than the pulp.

For more information:

Typing Style - Repetitive Injuries are NOT just about the Keyboard

High-Heeled Shoes

High-heeled shoes push the weight of the body forward.  In order to maintain an upright posture, women use extra muscular effort, primarily in the lower back, to keep themselves from falling forward.  This exaggerates the arch of the lower back. 

In addition to possible back, knee and ankle pain, women who wear high-heeled shoes can develop shallow breathing patterns and tight neck and shoulder muscles from the extra effort that it takes to counteract the forward thrust caused by the shoes. 

Lower the height of those high-heels if you are experiencing pain or change into flatter-heeled shoes throughout the day or if you are going to be on your feet for any length of time.  If you do change between different sized heels during the day, take the time to adjust your office chair to compensate for the change in shoe heights.

For more information:

How to Develop Healthier Ergonomic Habits

Sources:

Repetitive Strain Injury; Stifling the Pain in a Pinch

mothernature.com

RSI on trial: More people suffering from repetitive strain injury are seeking compensation in court as fresh evidence comes to light about the symptoms and causes of this crippling disorder

Newscientist.com; 11 September 1993; John Ballard

Marji Hajic is an Occupational Therapist and a Certified Hand Therapist practicing at the Hand Therapy & Occupational Fitness Center in Santa Barbara, California. For more information on hand and upper extremity injuries, prevention and recovery, visit Hand Health Resources

Labels: , , ,

Directory of Health Blogs