Many working-age adults in the U.S. have jobs that require eight hours per day or more working at a computer. This is in addition to their recreational screen time watching TV, using a computer, or their phone. Sitting at a desk in front of a screen can be harmful to your health because it reduces time spent on physical aerobic activity and increases body and eye strain.

According to the Occupational Safety and Health Administration, holding poor postures for long periods and performing the same or similar tasks repetitively are among the leading reasons for musculoskeletal conditions such as neck, shoulder, and back pain, as well as carpal tunnel syndrome. Leg pain and swelling have also been identified in a study of prolonged sitting among adults, as published in the Journal of Clinical Medicine.

Work-related conditions such as these are among the most frequently reported causes of lost or restricted work time. As noted by the Centers for Disease Control and Prevention, the hazards of prolonged work associated with sedentary seated work contribute to various chronic diseases, musculoskeletal pain, orthopedic conditions, metabolic syndrome diabetes, and ultimately, premature mortality.

Military Public Health Experts Agree

“Work-related musculoskeletal injuries account for some of the largest costs in injury claims and lost work time in the Department of Defense,” says Dr. John Pentikis, the

ergonomics branch manager at the Defense Health Agency Public Health in Aberdeen, Maryland, “In addition to finding solutions to reduce injuries related to jobs that require high repetition, lifting heavy objects, or vibrating equipment, we routinely are asked to assist with health concerns associated with poor postures and static seated positions commonly found at computer workstations.”

Eye strain injuries are also a concern.

“Because our eyes are designed to focus on distance, the need to adapt to work environments with everything close up can strain eyes,” says U.S. Army Maj. William Garrison, an optometrist working for DHA Public Health.

Garrison explains that spending long hours staring at a computer screen daily can result in vision blurriness, dry eyes, and headaches.

What can you do?

There may be no avoiding computer work for your job; however, simple changes can make your time at the computer workstation less stressful on your body and eyes. These changes can not only improve your comfort but also help to reduce the risk of musculoskeletal disorders or vision problems.

Pentikis and Garrison agree that that the position of your monitor is an especially important factor for reducing these risks.

“The best monitor position for you will depend on eye height, monitor size, viewing distance and viewing angle,” says Pentikis. “While service members and DOD employees can contact us for professional ergonomics advice, we recommend some general steps that anyone can take to help improve posture and reduce eye strain.”

Here are some tips from various DHA Public Health factsheets:

• Align your monitor screen above your keyboard. Ensure your keyboard, mouse and monitor are placed in front of you so you don’t have to twist your body or neck.

• Place the top of the monitor at seated eye height to allow you to gaze slightly downward to view the center of the screen. Tilt the screen slightly to accommodate your line of sight and to prevent glare.

• If the monitor is too low, place it on a monitor stand or, if necessary, a stable box. Many flat screen monitor stands are adjustable in height. Or use books or folders to raise the monitor so the top of the monitor is eye level.

 Use the desk height as a starting point and adjust your chair height so that your forearms and wrists are parallel to the floor. Adjust your armrests to support your upper arms. Check your posture is comfortable, including that your:

 Shoulders are relaxed. Upper arms are close to your body. Forearms and wrists are parallel to the floor.

• Don’t let your feet dangle. Add a footrest if the chair height doesn’t allow your feet to rest comfortably on the floor. Make sure your ankle and knee joints are at 90-degree angles.

• Reduce eye strain and headaches:

 Keep your monitor screen at approximately arm’s length.

 Use the “20-20-20 Rule.” Every 20 minutes, take a break for 20 seconds and look at things at least 20 feet away.

 Get glasses for near reading, such as computer bifocals or progressive lenses.

 Blink frequently to help keep the eyes moisturized.

 Increase font size and use a more readable font style.

 Clean the screen.

 Adjust brightness and contrast. Reduce sources of glare and light reflecting off the screen.

 Ensure lighting is in front of the screen.

 Consider adding an anti-glare coating on your glasses to reduce reflections off the front of the lenses.

If you wear bifocals, you might want to position your monitor lower to allow you to view it through the lower section of your glasses. Prescription computer glasses are set for the distance from your eyes to the monitor. This eliminates tilting your head back to see the screen through the lower half of your bifocals.

Additional Recommendations

• Get adequate aerobic and weight-bearing exercise. Adults are also encouraged to reduce the amount of their sedentary voluntary or recreational time. The CDC recommends adults achieve at least 150 to 300 minutes of moderate-intensity aerobic activity, like brisk walking or water aerobics, each week. Adults also need muscle-strengthening activity, like lifting weights or doing push-ups, at least two days each week. In addition to making you feel better, function better, and sleep better, following these activity guidelines can reduce risk of many health problems, including obesity, Type 2 diabetes and heart disease.

• Be mindful of gaming/leisure-time use of computers. Sometimes people have a good setup for their work computer and monitor, but when they switch to the leisure activity of playing video games or using their smart phone, all of the good computer work postures and positioning go out the window. Remember your posture, assess your screen distance, and be aware of the duration you are sitting during these recreational activities. Other recommendations include:

 Using a stable and supportive seating surface.

 Trying to hold the controller or phone in a neutral wrist position.

 Standing up, stretching and taking regular breaks to change position and rest your eyes.

For more information, visit these resources:

• DHA Public Health

 Ergonomics:

 https://ph.health.mil/topics/workplacehealth/ergo/Pages/default.aspx

 https://ph.health.mil/topics/workplacehealth/ergo/Pages/Ergonomics-Publications.aspx

 Military Vision Readiness:

 https://ph.health.mil/topics/workplacehealth/vcr/Pages/default.aspx

• Centers for Disease Control and Prevention

 NIOSH Ergonomics: https://www.cdc.gov/niosh/topics/ergonomics/default.html

 Physical Activity Guidelines: https://health.gov/our-work/nutrition-physical-activity/physical-activity-guidelines/about-physical-activity-guidelines

• Occupational Safety and Health Administration

 https://www.osha.gov/ergonomics

• National Library of Medicine

 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5618737/