“Mrs. Dabare, a 29 year old accountant at a famous bank for over 3 years, has been experiencing symptoms such as headaches and teary eyes since two weeks. Even though her current occupation requires her to work at the computer for more than 6 hours daily, since recent times she has been experiencing excruciating pain over the neck, shoulder and lower back regions during the period of computer use. These symptoms occur exactly an hour after she starts work and relieves with rest. The pain has become severe and constant over the past two weeks that she feels that she should settle for an early retirement”
The workstations in the past mainly consisted of a single table and chair requiring employees to engage in the tedious process of documentation. Over time, much change has taken place due to the globalization of the economy. Therefore, a present day workstation would not be able to be called one in the absence of a personal desktop. This in turn requires employees to sit in front of a computer for considerable time each day. With the rapid growth of computer usage in the workplace, considerable concern has been raised with respect to adverse health effects associated with computer use.
The increased exposure to computers has also lead to the increase in health implications. The most common occupation related health problems among computer operators are visual and muscular fatigue and discomfort.
Visual implications associated with prolonged computer use include eye discomfort, eye strain, blurred vision, teary or dry eyes, burning eyes and headaches. Factors contributing to these implications include poor lighting, poor visual corrections (i.e. adjusting the brightness of the monitor), the layout of the workstation and personal behaviours related to work organization.
Symptoms of muscular fatigue and discomfort include pain in the neck, shoulders, arms and the back. Neglected symptoms of muscular fatigue and discomfort give rise to musculoskeletal injury (i.e. muscle strains) which with time gives rise to musculoskeletal disorders (i.e. carpal tunnel syndrome, wrist tendonitis, epicondylitis etc.). Extended hours of computer use, sustained awkward postures, repetitive and forceful hand and finger exertions and work organizational factors have been found to directly contribute to muscular fatigue and discomfort.
Injuries resulting due to occupation do not only cause an economic burden to the employee but also poses a serious threat to the person’s health in the long term. Therefore, neglecting symptoms compromise the number of years a person is able to engage in a specific occupation as well as reduce the quality of life in the long run. It is simply understood that losing the number of occupational years pose a serious issue to the wellbeing of a family.
Health implications of the employees undoubtedly affect the employers as the success of an institution depends on the efficiency of the work force. Increase in the number of employees absent from work and the number of sick leave undoubtedly piles on the amount of unfinished work causing an economic loss to the company.
Therefore, concerns regarding occupational health and safety in the present day have increased the demand for the tactful intervention of ergonomics to the work environment. Ergonomics, a word constituting of two Greek words ergo (meaning work) and nomics (meaning rules or laws), is simply defined by the Oklahoma State University as the science of designing the job to fit the worker, instead of forcing the worker to fit the job. The good news that ergonomics offer the working community is that all occupation related injuries are preventable given that heed is paid to the rules laid down by it.
Ergonomics pertaining to workstation health and safety analyses the factors contributing to
visual and muscular fatigue and discomfort (listed previously) by broadly classifying them in to two categories as factors associated with the workstation and factors associated with personal behaviour. Though this form of categorization help to separately understand what changes require implementation in the modern day workstations, it should be noted that both categories are inter-related and inter-dependent. The current article expects to relate how each individual could adjust his workstation to better suit his personal behaviour and the amount of work.
Factors associated with personal behaviour relate about the accurate posture that each individual should adopt when working with a computer. According to the Ministry of Labour in Ontario, the following guidelines have been laid down about the posture that is to be maintained when sitting in front of the computer.
- The neck should be maintained in a neutrally straight position.
- The elbows should be at 90 degrees with the arms hanging naturally at the sides.
- The hands should be maintained in line with the forearms, which helps to maintain the wrists straight (without bending up, down or to either side)
- The natural curve of the lumbar spine (the third curve of the spine) should be maintained.
- Thighs should be roughly parallel to the floor, with the feet flat on the floor or on a foot rest (If your feet cannot be placed flat on the floor, use a foot rest to support your feet).
It should however be noted that maintenance of this posture is tedious unless supported by suitable workstation furniture, the correct layout of the furniture and the associated lighting. Therefore, the factors associated with the workstation relates to the layout, furniture and the lighting of the work environment. The present day workstations consist of the monitor, the key board and the mouse. These apparatus need to be placed in a suitable manner (as stated below according to the guidelines of the Ministry of Labour in Ontario) in order to support the posture guidelines stated previously.
The monitor should be placed so that the top of the screen is at the operator’s eye level. The distance between the operator’s eye and the screen should be roughly an arm’s length to allow for comfortable viewing. However, this distance varies with the screen size. Further, the monitor should be placed directly in front of the worker (for continuous or frequent viewing) rather than on the side as to avoid fatiguing head positions and visual fatigue. Adopting this position also helps in maintaining the neck in its neutrally straight position (according to the guidelines for posture).
The keyboard should be placed at a level lower than the elbows so that the home row of the keyboard is at an easily accessed by the fingers. This allows the worker to assume the elbow, wrist and hand posture laid down by the guideline. Keyboards placed too high require muscles to generate additional energy to maintain the position.
The level of placement for the mouse should be similar to that of the keyboard allowing for the accurate elbow, wrist and hand postures. The mouse should be as close to the worker’s side as possible. The cord or items on the desk should not limit the movement of the mouse. Use of a wrist rest or an arm rest further help to reduce the muscular effort required to maintain posture.
Further, the mouse buttons should be located so as to avoid awkward finger positions. The force required to make a button click should not be so great as to cause fatigue. It also should not be so little that the buttons could be clicked even on very fine touch as this would cause the user to hold the finger up.
When considering furniture related to the workstation, the computer chair and table play the most important roles. As height adjustable computer tables are expensive and limited in availability, the computer chair needs to be one that is most accurate and most suited to the individual. This in turn would compensate for the adjustments that cannot be achieved through the computer table. The guidelines for correct seating necessitate the following.
The computer chair should allow the maintenance of the accurate posture necessitated by the guideline. Important aspects pertaining to the seat base, height, seat pan, back rest and armrest need to be considered with regard to computer seating.
Seat Base – The computer seat should have a five-prong base with its feet set in a circle at least as big as the seat itself.
Seat Height – The computer chair should be height-adjustable so as to allow the feet to rest flat on the floor.
Seat Pan – This should be large enough to provide support for thighs and buttocks. However, it should not be so long that the front edge presses into the back of the operator’s lower legs.
It should also have a waterfall type (rounded and downward-curving) front edge so as to reduce the pressure on the underside of the thighs.
Backrest – Is more desirable if not fixed. It should include a lumbar support about 15-25cm above the seat pan.
Armrests – The two armrests should be around 45cm apart from each other and should not impede computer work. They should be of considerable length but should be set back about 15cm from the edge of the seat.
Even though in depth study of ergonomics relate and require implementation of more specific and fine changes to the work environment, making at least some of the changes stated above would undoubtedly ensure the addition of a considerable number of years to the occupational life of the individual. Some changes, though not significant, accounts for considerable decrease in task associated discomfort and injury. However, it is the responsibility of the individual to initiate his movement for health.
By: Miss. Tanya Wijesinghe
B.Sc. (Sp.) in Physiotherapy (Col.)
M.Sc. Rehabilitation Science (Melb.)
Physiotherapist/Physical rehabilitation specialist