Posture at the PC

As we start the new year of 2021 many people are experiencing a wildly different pace of life that is drawing people to even greater time spent on computers.  In the 21th century computer usage has exponentially increased, and with the COVID pandemic being the final catalyst, overall time spent in front of a monitor has dramatically increased.  More people are working from home computers, students are doing online learning, and video games have eclipsed movies and music as the largest form of entertainment.  This has led to significantly more hours being allocated to sedentary positions, with potential effects on our health.  For this blog I am going to dive deeper into some areas of the body that can be significantly impacted by prolonged time at the computer, and what we can do to take care of them.

Eyes:

              One of the first things that most people think of when discussing health as it pertains to being on the PC is our eyes.  Our eyes are the amazing organ responsible for vision as well as being associated with beauty and identity.  It makes sense why we want to take care of them.  From an anatomical perspective, the eye contains a dynamic lens and pupil that constantly adapts to the environment it’s in.  Tiny muscles called ciliary muscles actually pull on the lens to change its size and focus our vision, while the colorful iris reflexively adjusts to allow the right amount of light to pass through, adjusting the brightness of our vision. With computer usage far more prevalent than ever before we need to examine changes in the eye while on the computer, and how to avoid some of the health consequences that come as a result. 
 

 

https://www.ncbi.nlm.nih.gov/books/NBK11120/

             

There has been significant scientifically documented changes in function our eyes while looking at a computer screen, and this collection of symptoms has been termed “digital eye strain”.  During computer usage, it has been noted that our eyes significantly decrease in blinking and in something called the accommodation reflex.  Blinking distributes moisture over the surface of our eye, and accommodation contributes to our eyes focusing on objects close to our face. 

Also there are additional changes that have been observed following prolonged computer usage.  First, the size of roughly a third of the population’s pupils has been reported to remain overly constricted after getting away from the computer, leading to visual disturbance. Also, in the field of optometry there is a metric called, critical flicker fusion frequency (CFF), and in layman’s terms this is the ability for our eyes to differentiate between blinking light and steady light.  Multiple publications have demonstrated that CFF is significantly reduced after working on a task on the computer.  So now that we know there are changes in the eye during computer usage let’s look at two different conditions that could result from extended time on the computer and what to do about them.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6020759/

One of the most common changes in the eye that requires corrective care, especially in younger populations, is near-vision.  Medically termed myopia, near vision happens when the eye physically changes shape from a nice sphere, to more of an oval shape.  This results in an inability to focus on objects that are far away.  There are two similar theories for the origin of near-sightedness, one detailing that the increased ciliary muscle activity changes the structural shape of the eye, and the other stating that the eye is adapting to prolonged light that is out of focus.  They are similar because both hypothesize that looking at objects too close to our face facilitate this change.  Longer times at the computer does not bode well for potential near sighted-ness as it impacts both our ability to focus our eyes during computer use and for a time after.  For all of us at the computer, both work and leisure, frequent breaks are a necessity.  Our eyes need to be challenged to focus on things near and far.  Between games make sure to get up and look at something far in the distance.  At work make sure to structure breaks between tasks, and look out a window if at all possible. The national eye institute has stated that the greatest preventative factor for avoiding developing near sightedness is time spent outside.  This comes at a particularly difficult time with the pandemic keeping more people inside for longer durations, but actively caring for your eyes now is much easier than dealing with the fallout of altered vision down the road. 

 

Original picture taken from: https://fecarlington.com/differentiating-nearsightedness-farsightedness/

 

https://www.nei.nih.gov/about/news-and-events/news/myopia-close-look-efforts-turn-back-growing-problem

              The other prominent health concern for the eyes as they relate to computer usage is blue light exposure.  As screens have shifted to more LED based light sources there has been increased concern about the higher energy light coming from it, specifically blue spectrum light.  In research there is a lot of debate as to the effects, and preventative measures around blue light.  In particular there are two areas of concern.  The first is that blue light is accelerating age related damage to the part of our eye that sees color.  This is called age related macular degeneration.  The second is that blue light disrupts our sleeping rhythm.  A hormone called melatonin is secreted from the pineal gland and regulates our sleeping cycle.  When the eye is exposed to blue light, naturally our bodies interpret this as daytime and inhibits the production of melatonin.  This leads to insomnia and decreased alertness. Right now blue filtering glasses and apps are becoming much more common for reducing strain on the eyes.  Subsequent to this the best measure for combating blue light exposure is to reduce screen time before bed.  Many of us like to check our phones or play games late into the night, but avoiding light from screens for an hour before bed can help tremendously.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6353079/

              Picture taken from: https://retinaeyedoctor.com/2019/08/what-is-blue-light/

After conducting thorough research on the effects of computers on our eyes, one common theme in most publications, is that long term computer usage can significantly exacerbate other under-lying health conditions.  People with the conditions astigmatism, dry-eyes, macular degeneration, and presbyopia experienced significant discomfort, headaches, and worsening of their eye condition. So while taking preventative measures like frequent breaks, getting outside, and light filtering glasses, if you’re experiencing significant discomfort or changes in vision, seeking care from an optometrist or ophthalmologist is a great choice.

 

Wrists:

              The intricate nature of our wrists, coupled with constant activity while being on the computer leaves them susceptible to repetitive injury.  Our wrists are comprised of a group of eight little bones called the carpals.  The anatomy gets fairly complex, but these bones form an arch way on the back side of our wrists.  On the front side, a broad ligament called a retinaculum, provides the covering to make the wrist a functional tunnel.  Structures such as blood vessels, nerves, and tendons have to travel through this tunnel to arrive at their destination in the hand.

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Picture taken from: https://www.researchgate.net/figure/Cross-sectional-anatomy-demonstrating-the-deep-spaces-of-the-hand_fig1_301543920

  https://www.ncbi.nlm.nih.gov/books/NBK534779/

Small changes to the position of our wrists can make a large difference on the stress to the structures inside the wrist.  The most notable form of this is Carpal Tunnel Syndrome (CTS).  There are lots of causes of CTS, but when a nerve that enters the hand is compressed inside that tunnel it leads to pain, and even numbness in the fingers.  CTS plagues many Americans, and it is important to make sure that while on the computer we are taking the proper precautions to prevent it.  A study published in the Journal of Orthopedic Research measured pressure inside the carpal tunnel at different postures.  It concluded that the pressure was significantly increased when the wrist was bent back in extension, and was the lowest in a neutral position.  So keeping our wrists at a neutral position during the day is an excellent first step to preventing wrist injuries, and this is usually achieved by making sure that your desk space can accommodate neutral wrists on the keyboard and mouse.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2649727/

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Patients frequently want to know what the ideal posture for their arms is.  This is appropriate for people at work, studying, or playing video games at the computer.  At the National Institute of Health, The Division of Occupational Health and Safety sets clear guidelines for ideal computer usage posture. The ideal posture for maintaining our wrists starts all the way back at the shoulders. Keyboards should sit at a height that allows for the shoulders to be relaxed.  The next step is to make sure that forearms are parallel to the floor.  Mouse and keyboard should be at the same height, and wrists should be able to work in a neutral position, avoid extending them back or flexing them down.  Also pressure is increased in the wrist if it is bent toward your thumb.   Additionally do not rest your hand on the mouse when not using it.

 

https://www.ors.od.nih.gov/sr/dohs/HealthAndWellness/Ergonomics/Pages/prevention.aspx 

             

              There are a multitude of health conditions other than CTS that start at our wrists.  Some of the muscular structures that move our wrists up and down span the forearm and attach to the elbow.  Whenever I meet a patient who is suffering from long term elbow pain it is part of my initial consultation to evaluate their daily wrist movements.  Quick flicks of the wrist in particular are notorious for causing inflammation at the boney ends of the elbow.  Two different conditions affecting the elbow, caused by wrist movements, are tennis elbow and golfer’s elbow.  More medically known as medial and lateral epicondylitis, these conditions were traditionally caused by the quick movements of the wrists associated with these sports.  These conditions are currently on the rise however in people who are just using the computer.  Many ergonomic setups for data entry jobs as well maneuvers performed while gaming are leading to forceful flicks of the wrist at the computer.  I would highly encourage anyone who is experiencing long term elbow pain at their computer station to be cognizant of quick flicks of their wrist, and to potentially seek care from a chiropractor.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5367546/

Finally, we receive many questions about braces and wrist supports.  This is a topic that is better fielded on a case-by-case basis.  Depending on the demand that an individual has on their wrists, their current health status, and potential structures that have been injured, this can vary wildly from person to person so consider consulting a health care provider personally if this is something you’re still curious about.