Can a vertical mouse help improve workplace ergonomics?

We were not made to hold a mouse all day. Between the pressure on our wrist and the awkward positions, using a mouse for some four to six hours a day can cause discomfort and possibly tendonitis.  When grasping a generic mouse our palms and wrist rest on the mouse and we feel stress on our joints. When not in a neutral position or when having to reach for our mouse, the pressure on our joints becomes more pronounced. Additionally, when using a regular mouse the bones of our forearm twist (see the picture below). This places added stress on the joints and keeps the forearm in a non-neutral position, eventually contributing to discomfort.

In order to correct this position, I will often recommend the evoluent vertical mouse. This mouse allows the user to decrease the amount of pressure placed on their palm and wrist. Instead of constantly moving the wrist and fingers, which contributes to tendonitis, force is distributed more equally between the shoulders, forearm, and hands.  The forearm and hands are placed in a relaxed “handshake” position, preventing discomfort and injury.

Please remember that in addition to using a vertical mouse the user should continue to place themselves in a position where their wrist and forearm are aligned and in the neutral position.  The user should not have to reach very far for the mouse as well (for further details on the correct position of your wrist when using the mouse, see my post here).

The evoluent mouse comes in two sizes: small and regular.  If there are 7 inches or more between the tip of middle finger and the wrist crease, the regular size is you. The small size are for hands smaller than 7 inches.  You can also print out the following page and place your hand in the picture to determine which size will fit you best.  You also must inform the seller if you are right handed or left handed as the mouse is customized to the hand you use the mouse with.

Thanks for reading,

Shaul Lent OTR/L, MA, CEAS
Lead Ergonomic Specialist
Ergonomics Advance

(This is a continuation of a post.  To see Part I click here)

 

 

How can we avoid eyestrain?

1) Positioning

The first course of action is positioning the computer at an appropriate distance. We want to position the monitor at a distance that is not too far to diminish our ability to read yet not too close where it compromises our resting point of accommodation and vergence.   In general, we advise placing the monitor a little more than arms length away from the user.   The computer should be placed right in front of the user with the top of the computer at or slightly below eye level.

We recommend, also, adjusting the monitor slightly so that the top of the computer is farther away from the bottom (rotating the top of the monitor away from the user). This allows for a downward gaze, giving us the ability to remain more in our resting point of vergence. Looking slightly downwards, we can have the screen at a closer distance and still have the ability to view and read images with maximal acuity.

 

2) Word Font

Another way to avoid eyestrain and headaches is to increase the font size or zooming in slightly in order to easily read information on the computer screen. Squinting to view small type fonts place unnecessary stress on the eyes and promote poor back posture. Most importantly for people with eye problems, reading small print forces the user to view items closer, compromising our resting point of accommodation and vergance.

 

 

3) Avoiding Glare

Another suggestion that we make in order to decrease eyestrain and headaches is to reduce excessive bright light either from outdoor sunlight or intense indoor lighting. An office setting can often be intensely bright, causing unnecessary glare on the screen. This might mean removing one of the bulbs from a light fixture or simply positioning the computer away from a light source. We understand that many employee do not have control over how much light is present in an office setting or where there desk is stationed, however explaining to a human resource administrator or a supervisor about how glare promotes discomfort or effects productivity might give you the ability to make the necessary change. These changes might assist not only the individual, but the entire office. These suggestions include:

• Removing the middle bulb of a four bulb light fixture
• Closing the drapes, shades, or blinds, especially those that are directly in front or behind a computer.
• Position the monitor so that windows are to the side (perpendicular to the screen), instead of in front or behind the computer.

 

4) Neutralizing Screen Brightness

One of the easiest and most effective ways to avoid eyestrain is to adjust the brightness on the monitor. The brightness of the monitor should be the same as the brightness on the surrounding area. To test this, look at a white background on the monitor (can be this page). If the screen looks like a light source and is brighter than the surrounding area, the screen is too bright. If the screen seems dark and dull, you should increase the brightness.

 

5) Breaks

Another recommendation that can prevent eye strain is called the 20:20:20 rule. Recommended by many ophthalmologists and optometrists, the 20:20:20 rule states that computer users should look away from their computer every 20 minutes to gaze at a distant object, at least 20 feet away, for 20 seconds. The 20:20:20 rule allows you to relax your eyes and give you the opportunity to focus on different objects at a farther distance, rather than staring at the closest object to us, our monitor.

We also recommend, blinking during these breaks. Viewing a monitor tends to decrease the amount of times we blink, contributing to eye dryness and irritation.  Simply closing your eyes a few times for short 10 second periods can help with this.

 

These are a few recommendations that we can immediately implement to reduce eye glare. These solutions are inexpensive but can truly make a difference in the user experience, helping reduce eyestrain and headaches.

As with many things ergonomics, productivity is not compromised by implementing regular breaks or taking the time to adjust your monitor. On the contrary, the more detailed we are about avoiding glare and keeping ourselves within the resting point of accommodation and vergence, the more likely we are to contribute and work efficiently.

For more information, please feel free to contact us at (310) 467-5625.

 

Thanks for reading,

 

Shaul Lent OTR/L, MA, CEAS

Are we causing unwanted strain to our eyes by looking at the computer for long periods of time? Is there a way to continue working efficiently at the computer without it having to result in headaches?

There are a variety of solutions to protect your eyes when sitting at the computer. In this two part article, however, we explain steps that you can immediately take to protect your eyes, without having to resort to special light installations or glasses. While these more costly adjustments could be necessary, we first recommend taking these inexpensive steps to reduce eyestrain.

In this article, we charge ourselves with two objectives: 1) to explain why our eyes feel strained after looking at the computer for long periods of time 2) to provide five simple solutions to immediately implement in our daily computer tasks.  Part I of this post deals with the first objective, explaining why using the computer can cause eyestrain.  Part II deals with finding solutions to this problem.

Why do I develop eyestrain and headaches after using the computer for long periods of time?

In order to understand why we develop headaches and eyestrain after looking at the computer, we first must look at the normal processes of the eye. Two terms, the resting point of accommodation and the resting point of vergance, must be defined and explained in order to know the most neutral position for our eyes.

The Resting Point of Accommodation

Our eye’s adjusts to look at objects at different distances.  Eyes accommodate and readjust when viewing items far away and accommodate again when looking at an object close by. In a completely dark room, however, where our eyes are not staring at anything and do not need to adjust for distance, our eyes remain in the most relaxed, neutral position. This relaxed position is called the resting point of accommodation.

Most people prefer staying at the resting point of accommodation. This is the most relaxed position placing the least amount of stress on the eyes. Depending on a variety of factors including an individual’s eye anatomy and age, in order to achieve the resting point of accommodation you should sit, on average, about 30-40 inches from an object.

Resting point of Vergence

In addition to accommodating to various distances, our eyes have the ability to converge or look inward towards our nose in order to allow both eyes to see an items at the same place. The ability to converge on a single object prevents each eye from looking at an item separately, in turn preventing “double vision.”

Just like the resting point of accommodation, our eyes prefer to converge in a most relaxed position. When there is nothing to look at, the eye converges and remains in the most relaxed position called the resting point of vergence. The resting point of vergence is achieved when looking at an item about 45 inches away. However, when gazing downward at about a 30 degrees angle, the resting point of vergence can be achieved at a shorter distance, about 35 inches.

What does this mean for computer users?

For a person sitting too close to the computer screen and away from this resting point of vergence and accommodation, the muscles of the eye become strained viewing the screen at a close distance. This can result in increased eyestrain and headaches.  In addition to moving away from the resting point of vergence and accommodation, eye strain can be the result surrounding light or screen brightness, either being too dim or too bright. People will often need to squint to read words on a screen where the surrounding area or the brightness of the screen itself is too bright.  Avoiding glare and squinting, trying to read an article in bright light, contributes to eye fatigue and strain.

Click here to see Part II.

Am I really at risk for injury while using a computer?

We often think of injury as a sudden occurrence. “The back pain came from the heavy object I lifted yesterday.” “The broken nose came from an elbow during a basketball game.” “The hip fracture occurred after I fell.” The common thought on injury is that it is an instantaneous, unavoidable accident.

The truth is that injury comes in two forms: sudden impact acute injuries and chronic minor impact repetitive strain injuries (RSIs). Acute injuries are described above. They are fractures, dislocations and sprains resulting from a fall, a sudden movement, or an elbow to the nose. The second type of injury, RSIs, occur over a period of time. Repetitive strain injuries like De Quervains, trigger finger, and bursitis are the result of performing the same action on a constant basis.

A common type of RSI is tendinitis. Tendinitis is inflammation or irritation to the tendon, a flexible but inelastic cord which attaches muscles to bones and allows limbs to move.  As a result of constantly typing or using the mouse at the computer, the tendons in your fingers, wrists, or shoulders become irritated, inflamed, and can even tear. Discomfort will often radiate from the wrist to your fingers or from your shoulder to your bicep. After a diagnosis of tendinitis, it might even be difficult to hold items let alone continue typing or using the mouse for long periods of time.  Such discomfort is not caused by a sudden accident. Instead, over time, after repetitively using the fingers or neck to type and stare at a computer, tendons will start to become inflamed.

So how can we prevent tendinitis or the variety of other RSIs? Physical therapy, occupational therapy or surgery usually helps a person rehabilitate after one obtains an RSI. Yet, how can we save a person from these unnecessary conditions before?  For those who have rehabilitated or are at risk for an RSI, how can we prevent onset?

The key to prevention is adjusting your workstation to meet your specific needs. We are all different. People are distinguishable both physically and behaviorally. A one size fits all model cannot solve most ergonomic problems. Instead, we must aim to adjust an individual’s workstations so the client can sit in a neutral posture. A neutral posture means sitting and working in positions that are the most natural for your body while placing the least amount of stress on your limbs. For example, to keep the wrist in a neutral posture a person should have their wrist and palm aligned with their forearm while using the mouse and typing.  You should be able to draw a straight line from your elbow to your palm.   With the wrist in a neutral position, your shoulders should be in a relaxed position, not raised.  Your elbow should be close to your body and positioned at about a 90-110 degree angle. (To learn more about the neuteral posture of the wrist, see here.)  Additionally, a person should be using adjustable equipment – whether an adjustable chair, a keyboard tray, or a footrest – that gives a person the ability to adapt their workstation to meet his or her specific needs.  In short, we must creat an environment where the job fits the person, not vice a versa.  

We hope this post gives you a quick introduction about the risk of injury while using a computer and gives you some pointers about ways to prevent RSIs at work.

For more information, please feel free to contact us at (310) 467-5625.

 

 

Thanks for reading,

 

Shaul Lent OTR/L, MA, CEAS

How should I position my wrist when sitting at my workstation?  An ergonomic specialist will usually recommend positioning the wrist in a neutral position. 

But, what does this mean?

Keeping the wrist in a neutral posture means keeping the wrist aligned with the forearm.  You should be able to draw a straight line from your elbow to your palm.   When typing or using a mouse, your palm should not face the screen but the floor.

How can I accomplish this?

Most ergonomic specialist will say that ergonomic consulting is like Jenga.  You try to remove one piece, but always have to be careful that another section does not tip.  A person who simply follows the words, “Keep your wrist aligned with your forearm” might have to raise his or her shoulders or sit far from the desk.  This can lead to uncomfortable positions, shoulder, and back pain.

As with all things ergonomics, you need to make adjustment based on your own height, work habits, and regularly used computer equipment.  When we say keep the wrist in a  “neutral position,”  your shoulders, as well, should be in a relaxed position, not raised. Your elbow should be close to your body and positioned at about a 90-110 degree angle.  You should have your elbows above or level with the keyboard and mouse.  To accomplish this, you might need to use an adjustable keyboard tray or raise the height of your chair.  Sometimes, simply removing the legs of your keyboard can contribute to level wrist posture.   I would definitely play around with the height of your chair (maybe raising it a few inches) to try and achieve level elbow and wrist posture.  Use trial and error.  You should always adjust the equipment you own first before purchasing a new keyboard tray.

As an ergonomic consultant specializing in office ergonomics, when I am asked the question, “What is the correct position for my wrist?” I will say, “Keep it in the neutral position.  Let’s try to get you in this neutral position without impinging on the other aspects of good posture. “

Thanks for reading,

Shaul Lent CEAS, MA, OTR/L
Lead Ergonomic Specialist
Ergonomics Advnace

Wrist Stretches?

Which exercises help reduce wrist discomfort?  What is the most important stretch I can do to relieve the discomfort in my wrist?

When I perform an ergonomic assessment, I will often notice that the more clients use their wrist during computer tasks the more chance they will experience discomfort.  This is especially true for those who spend the majority of their day in front of a computer or a tablet.  In the beginning of the day,  a client might not experience soreness.  But, as the day progresses, the discomfort increases.  What can a client do to decrease this discomfort?  Is there are quick-fix, an exercise that you can perform?    As an ergonomic specialist trying to alleviate discomfort in the workplace, we will usually recommend developing a stretching routine for the wrist.  One exercise I often recommend is nerve gliding exercises (Note: If you have recent health problems, injury, surgery or if these exercises cause you more pain, consult with an ergonomic expert before continuing as you might not be performing the exercise correctly).  For this exercise, first make a fist and bring that fist near your face.  Next open your hand gently with your palm facing your face.  Then, slowly bend your wrist away from your face and hold this position for a few seconds. Repeat five times.  Depending on your needs, the ergonomic consultant will provide a range of other stretches as well as other nerve gliding exercises.  This should relieve some of the pain in your wrist, at least temporarily.

Though this should help, one should always realize that exercise is not everything.  No exercise, alone, can permanently relieve wrist discomfort.  During the ergonomic evaluation, we will often notice that the root of this aggravation is cause by repetitive motions.  An ergonomic consultant will often notice how the wrist is bent forward and increasing the aggravation.  Imagine the nerve in your wrist as a cord used to charge a cell phone.  If you continuously bend that cord, day after day, eight hours a day, the cord will probably become damaged.  It will be difficult to charge your phone as the connection between the phone and outlet is interrupted.  We can think of the wrist in the same way.  The more we place the wrist in awkward postures especially when using the mouse constantly, the more the messages going from our brain to our wrist and fingers is interrupted.  Discomfort is the result.  To solve the problem, an ergonomic specialist will need to adjust the workstation so that the wrist is placed in a more neutral position (See this post for more details about working in an ergonomically sound neutral posture).  The wrist and palm should be completely aligned with your forearm when mousing. The “cord” should not bend. This could be a very inexpensive proposal.  It might require the employee to adjust the way he or she is positioned and grasping the mouse.  Or, it might require the employer to purchase ergonomic equipment to allow the employee to grasp the mouse while keeping the wrist in a neutral position.  It all depends on the individual client, their current workstation, and the computer or tablet equipment they are currently using.  This is where an ergonomic consultant can help.  We each interface with our computers or tablets differently.  Each person is different and no two wrists are the same.  In order to truly solve a problem, recommendations from a ergonomic specialist is key to making the appropriate adjustments to relieve discomfort.

Thanks for reading,

Shaul Lent CEAS, MA, OTR/L

Sources:

Cooper, C.,  Fundamentals of Hand Therapy (Mosby Inc: 2007)