Playing computer time should not exceed how long

Computer Syndrome and Ergonomic Devices

One, Preface

Do you often feel neck and back pain, limb paralysis, tinnitus, and headaches after using a computer for a long time? If you have experienced or are experiencing any of these seemingly minor ailments, you are welcome to join the "modern computer syndrome". Due to the popularity of computers, you can't imagine that most computer users spend more time sitting in front of their computers than sleeping in their beds. While most people believe that the highest guidelines for maintaining good health are to eat healthy, get enough sleep and exercise, they overlook the potential negative effects of prolonged computer use. The concept of "ergonomics" is the study of how to design devices that fit the human body in order to develop a comfortable computer environment.

II. Wrist Injuries and Prevention

(1) Mice are designed to fit European and American hands, so they are generally too large for the Oriental hand. In fact, the better the mouse, should be to take into account the ergonomics of the "hand bow" of the structure. The so-called "hand arch" is the medical term for the wrist structure, when our palms are in a natural relaxed state, this time the wrist structure form is called "hand arch".

(2) Where is the median nerve?

The second most common is "soft tissue injuries" including bursitis, tendonitis, tenosynovitis, and ligament injuries. Symptoms are pain and soreness, and the thing about soft tissue injuries is - they are more comfortable with rest, and start hurting again with the slightest movement.

(2) Prevention and ergonomic devices

A. Mouse

Long-term use of the mouse will lead to lesions we can be divided into three kinds:

The first is called "tennis elbow", usually we use the mouse is to move the forearms and wrists, the operation of computers for a long time, not enough rest, long time easy to make the "extensor muscles" of the arm overuse, the "extensor muscles" of the arm is not enough to make the "extensor muscles" of the arm overuse. The first one is called "tennis elbow", which means that we usually move our forearms and wrists when we use the mouse, and we don't have enough time to rest.

The second type of lesion that can easily be caused by the mouse is known as the "trigger finger". Generally speaking, one of the most common actions that we take when using the mouse is to "point and click", which seems to be a simple and easy action, but in fact, it's not. This action seems to be simple and easy, but in fact it is not. The action of moving the mouse and pointing requires the cooperation of all the muscles in the hand, and if the muscles in the hand are in a state of tension for a long period of time in some operations that require a high degree of precision, such as computer-assisted drafting, then it is easy to form the "Pan-Ki-Shiatsu". The so-called "board machine finger" is the finger head showing a bent state, as if to buckle the board machine in general.

The third easy situation is "shoulder pain", which is usually caused by the incorrect height of the desk and chair. When we use the mouse, if there is no support for the forearm, the part of the force will be concentrated in the shoulder, think about it, use the whole shoulder to move the mouse, and for a period of time, the shoulder can be not sour? Therefore, when using the mouse, it is best to adjust the height of the desk and chair first, so that their arms can be flat on the desktop, the arm has a support, the shoulder can naturally relax.

The current ergonomic mouse on the market, for the prevention and treatment of injuries, more or less helpful. Because the ergonomic mouse shape is to a hand the most comfortable situation to design, this specially designed shape, can average hand and mouse contact pressure, in any point of the hand will not have too much pressure occurs, so the ergonomic mouse grip is particularly comfortable and not easy to tired.

B, keyboard

Keyboard design, from the early traditional keyboard, to today's ergonomic keyboard, the main direction of development, is to allow users to be more comfortable, and more space-saving direction of development, so the generation of separate keyboards, the invention of WISEPAD, are aimed at reducing the human body to use the keyboard the natural situation of the considerations made. Here are a few representative products.

(1) Reshaping the keyboard. The most common design seen today changes the curvature and shape of the existing keyboard so that the posture of the wrists and hands is close to the Neutral Position.

(2) Separate keyboard. Its design is to split the keyboard into two halves, on the one hand, change the angle of the wrist on the keyboard, on the other hand, let the width close to the shoulder width, so that the wrist and forearms closer to the neutral position, to reduce the ulnar side of the offset, some design is to be fixed in two halves, and some connected to a pivot, so that the user can adjust the angle of their own.

(3) Tent keyboard. The design focuses on reducing the action of turning the palms downward and the wrists inward when typing. Some designs allow the keyboard to be adjusted to a nearly vertical orientation, which takes the user more time to get used to. In addition, the visibility of the keyboard is poorer, and, the height of the entire keyboard becomes taller, which can be a nuisance in the placement of the computer workstation, and the wrist support is not good enough either.

(4) Ladle type keyboard arrangement. The keyboard is arranged in the shape of a bowl, the keys are arranged more tightly, users hit the keys, only need to finger downward movement, the purpose of reducing muscle activity, to prevent fatigue.

(5) Support keyboard. The keyboard is accompanied by a wrist support board, so that the wrists can have support, do not have to lean on the hard edge of the keyboard or desktop, and maintain a horizontal posture, reduce the muscle activity of the upper limbs, improve posture, but the wrists for a long time leaning against the support board, or will make the wrist channel pressure increases, so it is recommended that typing wrists should still be slightly elevated to avoid compression, and only at rest to do as a dependency.

(6) Negative tilt keyboard. Change the position of the height-adjusting bracket to near the front of the user, so that the keyboard tilted direction outward, the purpose is to let the user's wrists flatter, reduce the angle of dorsiflexion, but be careful, if the keyboard is placed too high when the position of the counterproductive, it will make the wrists are in an overly forward-flexed position.

(7) Minimal movement keyboard. The goal is to minimize hand movements to reduce the load on the muscles, such as switching to a side-to-side gentle jerking motion instead of tapping the keyboard.

(8) Accordion keyboard. The keyboard is significantly smaller and has fewer keys, and it is designed not to strike one key at a time, but to replace certain keys with a count of times, as if playing a harmony.

C. Wrist pads

According to the Occupational Injury Specialist, modern people use computers for long periods of time, and the medium of operation is not limited to the mouse, the keyboard and so on. One of the mouse for the longest time for the use of equipment, but when the use of the mouse for a long time, the wrist and arm will produce a similar exercise or excessive fatigue of the soreness, if it continues to deteriorate more likely to cause sprain of the carpal bones or tendon inflammation, collectively referred to as carpal tunnel syndrome.

Functions of the pads:

(a) Ergonomically designed to prevent carpal tunnel.

(b) Special material surface that is soft to the touch and not hot.

(c) High-density non-slip material, labor-saving and effective.

Sen, shoulder, neck and back injuries and prevention

(a) ergonomic computer desk and chair

Computer family long time sitting on the keyboard, to have a set of comfortable desk and chair, will not feel back pain. In the end, what kind of computer desk and chair to meet the ergonomics of it? Computer chairs should have armrests, seat height can be adjusted, sit down and let the thighs and knees into 90 degrees, are the ideal chair. According to a number of rehab physicians in the newspaper media appeal can be seen, the computer family posture is very important, otherwise long hours of work, not only caused by back and neck pain, but also produce carpal tunnel syndrome, over time, may have to undergo rehab, if you choose the appropriate desk and chair, I believe that can alleviate this kind of discomfort.

Seat height is the first thing that can disperse the pressure on the legs and keep the blood circulation smooth. As for the design of the computer desk more need to pay attention to the eye angle, the angle of vision directly affects the head posture, the incorrect posture will often make the user produce shoulder blade pain, and even easy to suffer from fifty shoulders, will make myopia deepen! The best choice of computer desk screen can be tilted angle of the design, so that the computer to meet the body's use of the angle to ensure that not consciously overuse of computers, resulting in harm to the human body.

(ii) the correct posture of the computer

1, feet should be flat on the floor.

2, the seat must have a backrest, lumbar back with cushions to reduce muscle fatigue, and to be able to adjust the height.

3, the keyboard should be placed in the appropriate position, should make the elbows about 90 degrees, that is, the upper part of the arm is vertical, the lower part is horizontal.

4. The upper edge of the screen should be parallel to the eyes, with the head tilted forward 30 degrees to reduce the pressure on the neck.

5. Keep an arm's length away from the screen, but not too far. Behind and in front of the screen are places where radiation is strong, and it's best not to stay within 4 feet of it.

6, the same posture to operate the computer not more than 30 minutes, and should be in a fixed time to leave the seat to move muscles, every hour of use of the computer must take a break of 10 minutes, do not use more than 4 hours of continuous.

7, pay attention to the location of the documents, minimize the number of eyes and neck movement.

8, should be moderate rest, the eyes can not be a long time to stare at the screen, at the same time to pay attention to keep the screen clean.

The damage and prevention of eye injuries

(1) Computer Terminal Syndrome

As far as the general public knows, the symptoms caused by prolonged and continuous computer operation are, in addition to the so-called "neck-shoulder-wrist syndrome", psychoneurological symptoms, and general fatigue; the most important one, and also the most important one for long-term computer workers, is the problem of the eyes. Long-term use of computers causes functional problems, including low vision, eye fatigue, conjunctivitis, tear secretion disorders ..... These include low vision, eye fatigue, conjunctivitis, tear secretion disorders, etc. These visual impairments, including low vision and eye fatigue, are most commonly experienced by computer terminal users.

Eye fatigue mainly includes five items: regulatory eye fatigue, muscular eye fatigue, symptomatic eye fatigue, unequal eye fatigue and neurological eye fatigue. Eyestrain caused by computer terminal syndrome is mainly regulatory and muscular.

(ii) How to deal with myopia?

Generally speaking, if the myopia is more than 150 diopters, it is common to squint or cross your eyes due to blurred vision. This will cause uneven force on the eyeballs, resulting in lengthening of the anterior and posterior axes of the eyes, which will lead to a rapid increase in the number of diopters, so it is recommended that if the myopia is more than 150 diopters, a doctor's prescription of eyeglasses is required to correct the visual acuity.

(3) How to prevent myopia from getting worse?

Generally, we would recommend that people who play computer for a long time often engage in outdoor activities, see more mountains and trees, do not live for a long time in a small room to watch TV, play computer, and should be instructed in the correct reading posture, the computer screen and the eyes to maintain at least thirty-five centimeters from the distance, and remember to play the computer to have sufficient light, use half an hour to rest for at least ten minutes, look into the distance or closed eyes. Look into the distance or close your eyes to refresh yourself. In addition, there are eye drops used to paralyze or relax the ciliary muscles, which can help prevent myopia and treat pseudomyopia. It is advisable to observe the above points. If the myopia continues to increase after observing the above points, it may be due to hereditary factors and there is no need to blame yourself too much, but hereditary cases are quite rare. Avoiding prolonged close-distance work, not living in small spaces, maintaining good reading habits, avoiding wearing glasses that exceed the actual prescription, using effective ciliary muscle paralyzing eye medications, and working closely with an ophthalmologist can all help prevent myopia from worsening. At the same time, we should pay attention to adequate nutritional intake and a balanced diet, and allow our eyes to rest sufficiently when we experience eye fatigue.

These are not difficult to do, simply put, let the patient to develop a healthy and normal life habits, "vision should be far away", "living space as much as possible", "more exercise", if the patient can not cooperate, in fact, the doctor has a last magic weapon, is every day or every other day or two days before going to bed or sleep a little bit of prevention of myopia eye drops, although the patient in the daytime may have a little bit of "photophobia", but the patient is also a little bit of "photophobia". Although the patient may have a little bit of "photophobia" trouble during the day, but the effect of preventing myopia is very good.

(4) Prevention of dry eyes:

1. Proper lifestyle, getting enough sleep and not staying up late.

2. Eat a balanced diet with less stimulating foods and more fruits and foods rich in vitamins A, C, and E.

3.

3. Change your eye habits and take regular breaks, suggesting that you take a 5-10 minute break every 50 minutes, and pay attention to the number of times you blink and the magnitude of your blink.

4. When you wash your face, pay attention to the eyelids and eyelashes, and make a habit of applying hot compresses every night.

5. Do not take oral medications, especially sleeping pills and sedatives, and if you need to take them, discuss them with your specialist to minimize the dose.

6. Diseases of the surface of the eye, such as cornea, conjunctiva and eyelids with inflammation, allergies, injuries or lesions need to be actively treated with ophthalmologists. Do not buy your own medicine to use, because some drugs, long-term point will reduce corneal sensitivity, and even cause conjunctival keratinization, resulting in dry eye.

7. Especially do not stay in the dry room in the cooler to use the computer, every once in a while you can go out for a walk, and then back to the computer desk.

Wu, conclusion

Some people say: "The computer is the greatest invention of the twentieth century". The popularization of computers has been an unstoppable trend, playing an increasingly important role in our lives. Therefore, it is believed that the diseases caused by the use of computers will become more and more common, and how to prevent them and treat them as early as possible will become our responsibility. Computer companies should develop more ergonomic, low-radiation products to increase the safety of their use. Computer users should also pay attention to their own health by maintaining correct posture and taking proper rest. Parents and teachers, in particular, should pay attention to children's habits and hours of use of computers, correct their postures and remind them to take proper exercise and rest so as not to affect their normal development. The Government should play a supervisory role and step up publicity on the safety of computer use. While we enjoy the convenience and comfort of computers, we should also pay attention to and prevent the negative effects of computers, so that we can ride in the magical world of computers without any worries!

References

1. The study of computer terminal syndrome, Journal of the Ophthalmological Society of the Republic of China, 85, Vol. 35, No. 4.

2. computers & visual stress ---staying healthy, John, 1991.

3. an investigation of health complaints and job stress in display Smith MJ, 1981.

4. Information on the web and in computer exhibitions.

The results of experimental research and investigation and observation show that the health hazards of electromagnetic radiation are multifaceted and complex, and the main hazards are as follows:

1. Hazards to the central nervous system

The nervous system is very sensitive to the effects of electromagnetic radiation, and after repeated effects of its low-intensity, the functions of the central nervous system are altered, and neurasthenia syndrome occurs, with the following symptoms: headache, dizziness, and neurasthenia. Performance of headache, dizziness, weakness, memory loss, sleep disorders (insomnia, dreamy or sleepy), daytime dozing, agitation, sweating, palpitations, chest tightness, hair loss, etc., especially sleep difficulties, weakness, sweating and memory loss is more prominent. All these indicate that the brain is dominated by inhibitory processes. Therefore, in addition to the above syndromes, the victim also shows short-term memory loss, visual-motor response time value is prolonged; poor hand-cerebral coordination, the performance of the number of scratching speed slowed down, there are more errors.

2. Harm to the body's immune function

The body's resistance to decline. Animal experiments and studies and surveys on the effects of radiation on the population show that the human body's white blood cells phagocytosis of bacteria and the number of phagocytosis of bacteria are reduced. In addition, the long-term effects of electromagnetic radiation, its antibody formation is significantly inhibited.

3. Effects on the cardiovascular system

People affected by electromagnetic radiation, hemodynamic disorders often occur, vascular permeability and tension decreased. Due to the influence of the vegetative nervous system, people mostly show symptoms of bradycardia, and a few show tachycardia. Victims show fluctuations in blood pressure, which starts to rise, then returns to normal, and finally becomes low; the electrocardiogram shows a drop in the voltage of the R T wave, which is an allergic reaction of the vagus nerve and the result of myocardial trophic disorders; the prolongation of the P?Q interval and the widening of the P wave indicate that the atrioventricular conduction is not working well. In addition, long-term exposure to electromagnetic radiation, its cardiovascular system diseases, will be earlier and easier to promote its occurrence and development.

4. Effects on the blood system

Under the action of electromagnetic radiation, the peripheral blood image can appear white blood cell instability, mainly downward tendency, white blood cell reduction. Erythrocyte production is inhibited, the appearance of reticulated red blood cell reduction. The results of health surveys of people who operate radar show that most of them show a decrease in white blood cells. In addition, when radio waves and radiation act on the human body at the same time, the effect on the blood system than a single factor can produce more obvious damage.

5. Effects on the reproductive system and heredity

Long-term exposure to ultrashort wave generators can be seen in men with decreased sexual function, impotence; women with menstrual cycle disorders. Due to poor blood circulation in the testes, which is very sensitive to electromagnetic radiation, spermatogenesis is inhibited and fertility is affected; the oocytes appear to be denatured, destroying the process of ovulation, and making women lose their fertility.

High-intensity electromagnetic radiation can produce genetic effects, so that the testicular chromosomes appear aberrations and mitotic abnormalities. Women who have received short-wave diathermy at an early stage of pregnancy or before pregnancy have suffered from congenital birth defects (malformed babies) in their offspring.

6. Effects on the visual system

The eye tissue contains a large amount of water, easy to absorb electromagnetic radiation power, and the eye's blood flow is small, so in the role of electromagnetic radiation, the temperature of the eyeballs is easy to rise. Elevated temperature is caused by the main conditions of cataracts, rising temperatures lead to rose eye lens protein coagulation, most scholars believe that lower intensity microwave long-term effect, can accelerate the aging of the lens and turbidity, and may make the colored field of vision narrowing and dark adaptation time is prolonged, resulting in some visual impairment. In addition, the role of long-term low-intensity electromagnetic radiation can contribute to visual fatigue, eye discomfort and eye dryness and other phenomena

7. Electromagnetic radiation carcinogenic and cancer-causing

Most experimental animals by microwave action, can make the incidence of cancer increased. Some microwave biologist's experiments show that electromagnetic radiation will promote the human body (genetic), particulate cell chromosome mutations and mitotic abnormalities, and make some tissues appear pathological proliferation process, so that normal cells into cancer cells. U.S. embassy personnel abroad for a long time by the microwave eavesdropping emitted by a high degree of electromagnetic radiation, caused by the embassy personnel, white blood cell count rise, cancer incidence rate is higher than normal people. Another example is the area under the influence of high-power long-distance microwave radar, after investigation, the local cancer patients increased sharply. Microwave thermogenic effect on human tissues, not only can be used for physical therapy, can also be used for the treatment of cancer, so that the center of the cancerous tissue temperature rises, and destroy the proliferation of cancer cells.

In addition to the above health hazards of electromagnetic radiation, it is also on the endocrine system, hearing, material metabolism, morphological changes in tissues and organs, can have adverse effects.