The computer is a vital tool in many different occupations. However, long periods of working at a computer can increase the chance of developing an injury. Muscle and joint pain, overuse injuries of the upper limbs and eyestrain can result from inappropriate computer use. The risks can be reduced or eliminated with proper work space design, improved posture and good working habits.

Causes and Symptoms
             The causes include a lack of appropriate breaks, improper monitor height, resting the arm or wrist on a hard surface while typing, keyboard or mouse placed too high, bizarre leg positioning and bad posture. As for symptoms, they include pains in the back, neck, shoulder, hand/wrist, arm or anterior knee. There may also be some visual strain, numbness or weakness of the hand and Pilot Seat Syndrome.

Computer Related Injuries (CRI) is defined as a constellation of work related symptoms in computer users. It is a diffuse disorder of muscle, fascia, tendon and/or neurovascular structures, which typically involves, the neck and upper limb; but any part of the body may be affected. It is also known as Repetitive Strain Injury (RSI), Cumulative Trauma Disorder (CTD), Work Related Upper Limb Disorder (WRULD], Musculoskeletal Disorder (MSD), or Occupational Overuse Syndrome (OOS). It is primarily a physical problem, not a psychosomatic' one, though stress may aggravate symptoms. Unfortunately, Indian medical professionals in general are not trained to diagnose or treat
, these injuries, as they are a relatively recent phenomenon here.

             For a start, CRI accounted for 66 per cent of work-related illnesses in the US, in 1999. Then, the estimated costs in lost productivity and compensation due to it are in the region of $60-100 billion annually. Most importantly, no one is immune to CRI, and it can seriously disrupt work and domestic life. 20-25 per cent of all computer users worldwide are estimated to have it, which is why it is essential to raise public awareness as quickly as possible before a new generation of computer users is exposed to the risks.

Scenario in India
           The pattern and nature of CRI in India is, significantly different from that in the West. What may work there may be a disaster here. There may be significant anthropological differences in body shape and dimensions, work practices and furniture design that only a comprehensive study can unearth. As these problems are unique to our country, so should the solutions.
The recent survey has found that over 50 per cent developed CRI within one year of starting their IT career, clearly suggesting a lack of knowledge about CRI and how to protect their body from injuries. The male; female ratio of CRI patients in India is considered 4:1, the median age, 27 years, and less than 0.5 per cent had any predisposing medical disorders. The common symptoms were found to be back pain (47 per cent), neck pain (35 per cent], shoulder pain (34 per cent), finger pain (26 per cent), arm pain (22 per cent), visual strain (20 per cent), tingling/numbness of hands (16 per cent), and weakness of hand (10 per cent). Over 50 per cent patients who had developed serious tendonitis of hand or neurovascular compression, reported having longstanding aches and pains in the neck and shoulders, which they had considered "normal" for computer users and ignored.
The commonest predisposing ergonomic factors were lack of appropriate breaks (86 per cent); improper monitor height (60 per cent); keeping the mouse at a higher than recommended height (54 per cent); resting the arm or wrist on a hard surface while typing (42 per cent); and keeping the keyboard too high (40 per cent)

The only solution is prevention by creating awareness, of proper computer usage and helpful HR guidelines. Undoubtedly, the onus of responsibility to provide safe working environments and preventive training for workers lies with the organizations.

Indian computer users, in general, work on a keyboard and mouse a lot, and their workstations do not permit adequate adjustability, leading to secondary postural distortions and neurovascular compression in the neck. Indian office tables are fixed at a height of 2.5 feet, irrespective of body dimensions. Also, no Indian chair fulfils all ergonomic criteria for adjustability, exacerbating the problem. Most importantly, only 'genuine' patients report symptoms in India. Most professionals are reluctant to admit having CRI' for fear of retrenchment or being labeled 'psychotic'.
We shall now briefly discuss about various Computer-Related Injuries that affect specific parts.

Computer vision syndrome
[CVS) is a temporary condition resulting from focusing the eyes on a computer display for protracted, uninterrupted periods of time. Some symptoms of CVS include headaches, blurred vision, neck pain, fatigue, eye strain, dry, irritated eyes, and difficulty refocusing the eyes. These symptoms can be further aggravated by improper lighting conditions (i.e., bright overhead lighting or glare) or air moving past the eyes (e.g., overhead vents, direct air from a fan). CVS has not been proven to cause any permanent damage to the eye.

Pathophysiology

CVS is caused by decreased blinking reflex while working long hours focusing on computer screens. The normal blink rate in human eyes is 16-20 per minute. Studies have shown the blink rate to decrease to as low as 6-8 blinks/minute for persons working on the computer screen. This leads to dry eyes. Additionally, the near focusing effort required for such long, hours puts strain on ciliary muscles of the eye. This induces symptoms of asthenopia and leads to a feeling of tiredness in the eyes after long hours of work. Some patients present with inability to properly focus on near objects after of short duration. This can be seen in people aged around 30-40 years of age, leading to a decrease in the accommodative focusing mechanisms of the eye. This can be a setting for early presbyopia.

Dry eye is a major symptom targeted in the therapy CVS. The use of over-the-counter artificial tear solutions can reduce the effects of dry eye in CVS.
Asthenopic symptoms in the eye are responsible much of the morbidity in .CVS. Proper rest to the eye and its muscles is recommended to relieve the associated eye strain. Various catch-phrases have been propagated for spreading awareness about giving rest to the eyes while working on computers. A routinely recommended approach is to" consciously blink the eyes every now and then (this helps replenish the tear film), and look out of the window into a distance object or the sky (this provides rest to the ciliary muscles). One of the catch phrases is the "20-20-20 rule":
Every 20 minutes, focus the eyes on an object 20 feet (6 meters) away for 20 seconds. This basically gives a convenient distance and time-frame for a person to follow the advice from the ophthalmologist Otherwise, the patient is advised to close his/her eyes (which have a similar effect) for 20 seconds, at least every half hour or even more frequently.
Decreased focusing capability is mitigated by wearing a small plus powered over-the-counter glasses (+ 1 to + 1.50) It helps such patients regain their' ability to focus on near objects. Other occupations such as tailors engaged in embroidery can experience similar symptoms and can be helped by these glasses.

*(Note: This topic is selected from Junior Science Refresher Magazine!)