Health Information

Computer and Health
A) Health Problem
shutterstock_77654926Eye care
Short-sightedness (myopia)
The main symptom of short-sightedness (myopia) is where distant objects appears blurred, while near objects can still be seen clearly.
It may be caused by a number of factors including genetic and environment. Heredity may be the genetic factor while environment refers to poor reading habit, improper light exposure, poor printing and glare by reflective paper.

Dry Eye Syndrome
Dry eye syndrome happens when eyes are kept wide open for heavy reading, resulting in insufficient lubrication and moisture on the surface of the eye and causes dryness on the surface of the eyes.
A normal person will blink 20 times per minute for the tear to reach the surface of the eyes to supply fluid and nutrient. But when one stares at the screen, eyes blinking rate will drop instantly, so we need to make sure that we blink our eyes regularly.
Dry Eye Syndrome and itchy eyes may stimulate eyes to produce excessive tears and cause tearing.

Blurred vision
When one faces the screen closely and eyes move between the screen and the environment, it causes the eyes to change focal length constantly and that leads to ciliary muscle fatigue. When we could not properly focus our sight due to ciliary muscle fatigue, it will cause double vision, blurred vision, eye fatigue and headaches.

shutterstock_291344606Musculoskeletal health
Back pain
Maintaining static posture and doing repetitive movements for a long period will cause fatigue muscle.
Maintaining bad body posture for a long period could lead to chronic fatigue on ligaments and cartilage and causing stiff neck and waist pain.

Hunched back
90% of the hunched back patients have this disease due to poor body posture. They have the habit of leaning their body and shoulder forward, known as “Postural Kyphosis”. Over stretching of the ligament will cause fatigue shoulders and affects lungs expansion.

Scoliosis refers to curvature of the spine to the left or to the right that resembles a “C” or a “S” shape.
During puberty period, the growing rate of the muscle and the joint bones is uncoordinated and causes spine lateral.
Inappropriate posture on everyday life leads to soft tissues fatigue or joint dislocation is one of the causes contributes to scoliosis.

shutterstock_174195206Hand health
Carpal tunnel syndrome
Carpal tunnel is a narrow passageway located on the palm side of your wrist.
There are tendons passing through the tunnel that bend your fingers.
There are thin synovial linings on the tendons functioning as the lubrication.
Exertion and repetitive movements on the hand and wrist will result in thin synovial linings swollen, causing the compression of the main nerve and produces the numbness of the hand.

When fingers kept clicking and pressing on the touch screen for a long period, the flexion of the fingers and friction between tendons and the sheath of the tendons will be tremendously increased.
In early stage, it will cause mild injury but it will cause chronic inflammation if it experiences chronic injury.
Pain occurs on Radius (Beside the thumb) and searing on the area around the Radius.

B) Environment in using computer/ electronic device
Avoid putting your screen under the lightings or in front of the windows to prevent reflection, glare and produce light and shadow.
The distance between eye and computer screen should be kept at least 50cm while distance for the tablet should be kept at least 40 cm and distance for the smartphone should be kept at least 30 cm. (Could use palm length as measurement, palm length for a primary student is about 10cm)
Make sure the screen is projecting clear and stable image, one could tune the brightness and contrast.
Display suitable font size, it is better to keep the top row of the word on the screen at the same level or slightly lower than the eye level.

Keyboard/ Mouse
There should be enough space (5-8cm) to support both hands.
Consider using a wrist pad or tiltable keyboard
Both forearms and arms should form a right angle when using the keyboard
Avoid pressing hard/ grabbing hard on the mouse
When using mouse, avoid tilting your wrist forward/ sideward.

Avoid using handphone/ electronic device in the darkness, this will cause the light source from the screen enter directly into your eyes, similar to the situation where the light of the torchlight shoot directly into your eyes, this will create direct injury to the pupil and macula of the eyes and result in macular degeneration of the user.
Avoid using e- devices/ computer to carry out exciting activities (such as video games) before sleeping, enable your body to get prepare into sleeping mode.
Avoid using e-devices when walking/ taking public transport, trying to focus in reading small letters in addition to body movement at the same time will burden your eyes.
Use a stable foot rest to support the lower limb if the seat is too high and the legs are not able to rest flat on the ground.

Things to keep in mind when using e-devices
Due to static posture and repeated movements, necks / wrists/ fingers are easier to get hurt.
Do not use fingers to hold, instead, use palm or forearm to support the weight.
Elbow should keep nearer to the body or rest on the table top to share the pressure of the wrist.
Avoid placing the e-device on the lap to avoid head bows for a long period.

Stretching Exercise (Computer)

Eyes exercise

1. Follow the eye bone’s subsidence line, press gently on the upper and lower position for 3 times.
2. Use similar method as above to massage gently on several areas.

Neck exercise

  • Put both your arms naturally on both sides
  • Slowly tilt your head forward, stretch your back neck.
  • Hold for 5 seconds.
  • Put both your arms naturally on both sides
  • Turn your head to the left then to the right.
  • Hold for 5 seconds for each side.
  • Put both your arms naturally on both sides
  • Tilt your head to the left and right.
  • Hold for 5 seconds for each side.
Shoulder exercise Upper limb exercise Shoulder and upper back exercise
  • Raise up both shoulders and slowly roll backwards, repeat 10 times.
  • Holding both hands together with fingers crossed and stretch to the top, reverse the palms and stretch upward.
  • Hold for 10-15 seconds.
  • Relax the shoulders
  • Remember to take a deep breath when doing the exercise.
  • Get seated, holding both hands together with fingers crossed on the back of your head, elbows extent outward, straighten the upper body.
  • Both shoulder blades compress inward and let the upper back and shoulder blades feel the pressure.
  • Hold for 5 seconds and relax.
  • Gently move your fingers away from each other as far as you can, hold for 10 seconds and relax.
  • Stretch both hands to your front, face your palm downward, gently tilt your wrists upward. Hold for 10 seconds. Then gently tilt downward, hold or 10 seconds.
C) Harm brought about by improper use of computer

Working in front of the computer for a long period and neglect in correcting your postures will lead to body discomfort; reduces working efficiency and affects your body wellness. Common discomforts are:
1. Upper limb discomfort and pain
Operating computer for a long period and being in a static posture will cause temporary pain and fatigue. Affected areas include hands, arms, shoulder and neck. If no action is taken to improve the condition, it will result in more severe cumulative musculoskeletal disorders.

2. Eye fatigue
Long working hours in front of the computer screen and lack of rest will cause tired eyes. Besides, if the quality of the screen display is poor or if there is inadequate lighting at the working place where one needs to be more focused on the screen; this will easily lead to eye fatigue.

3. Body fatigue and mental stress
Working on the computer usually requires repetitive operation; therefore it is easy to cause operator to feel tired. If operating the computer requires massive and frequent operation, it will increase the operator’s mental stress.

Information sources
Hong Kong Private Practice Physiotherapist Association
Occupational Safety & Health Council
Student Health Service – Department of Health
Tung Wah Group of Hospitals
University Health Service – The University of Hong Kong

Special thanks to Medical Society HKUSU 2015 providing the health info.

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