This article sets out recommendations for the design of office workstations which will help prevent work-related health problems.
 |
|
INTRODUCTION
Work-related musculoskeletal disorders (WMSD) are syndromes characterised by discomfort, impairment, disability, or persistent pains in joints, muscles, tendons or other soft tissues. They are the most common self-reported, work-related illness in many workplaces. High incidence rates for WMSDs have been reported for workers in a wide range of industries including office work, manufacturing, agriculture and numerous manual materials handling occupations.
WMSD can result in direct costs, such as compensation and medical expenditure, as well as indirect costs such as disruption in productivity and quality, worker replacement costs, training and absence costs. It has become a major concern because of the negative impact on the health and productivity of employees and is therefore a significant problem for employers and workers to pay attention to.
As many of us spend a significant amount of time on our personal computers at work, good ergonomics at the work place is critical. By learning the proper way to handle and use office equipment, we will be able to prevent undesirable health problems such as headaches, neck and shoulder pain.
WMSD AMONG OFFICE WORKERS
In a recent study conducted by SGH on the prevalence of MSD among office workers in Singapore, it was found that 73.4% of the 324 respondents reported experiencing pain in at least one of the body parts (see Chart 1). The body parts with the highest report of pain were neck (46%), shoulder (42%) and low back (42%). There was a higher prevalence of MSD in female (78.8%) compared to male (63.9%) and this was statistically significant (p=0.003).
CAUSES OF WMSD
Some of the possible causes of the high prevalence of aches and pains among office workers include both physical workload and the organisation of work in. There are various factors that may affect these conditions.  A substantial amount of researches has provided evidence of associations between musculoskeletal disorders and certain work-related factors such as vibration, posture, force and repetition. In an office environment, poor postures and the prolonged sedentary work seem to be the key factors. Poor design and layout of workstations can aggravate the awkward postures adopted by workers. Besides these physical factors, psycho-social factors such as job satisfaction and mental stress may influence the report of WMSD.
Shoulder elevation, trunk flexion, and low
back not supported when using the laptop computer
Awkward postures adopted by office workers
Observation of postures adopted by office workers at work showed that many of them performed their work in awkward postures. The common observations were shoulder elevation, neck and low back flexion.
Poorly designed computer workstations
Awkward postures, often aggravated by poorly designed workstations, can increase the risk of people getting WMSD.  WMSD can be very painful and sometimes permanently disabling. The disorder can interfere with all aspects of daily life. Sometimes even the simplest household chores, hobbies and social events can become unmanageable. Financial costs can be severe. Employers can experience costs in a variety of ways such as lost time at work, medical treatment and disability cost.
Hence, it is important to have workstations that are well designed for the users and the intended tasks to be performed.
Back not supported when sitting at
the edge of the chair
WORKSTATION DESIGN
The main components of an office workstation include the desk, chair and the equipment used to perform office task, often a computer. When designing a workstation, it is important that you consider task that have to be performed, and the type of equipment used. Flexibility is the key in workstation design.
Posture and Movement
The way the workstation is designed affects the posture that one adopts while working. Therefore, the workstation should be designed to place the person in the best position to enable him/her to perform the work in comfort.
To assist us in designing offices that fit our local population, a Code of Practice for Office Ergonomics was published in November 2005.
CODE OF PRACTICE FOR OFFICE ERGONOMICS
The Code of Practice for Office Ergonomics or SS 514, was initiated by the Ministry of Manpower and published by SPRING Singapore (Standards, Productivity and Innovation Board). The purpose of this Code on Office Ergonomics is to provide guidance to users, employers and manufacturers responsible for the introduction of occupational health practices, the specification and procurement of office equipment. With the rapid introduction of information technology, the use of personal computers (PCs) has become prevalent. Unfortunately, PCs have often been installed in offices without due attention to ergonomic principles. This can cause muscular aches and pains, visual discomfort, work stress, lower worker motivation, absenteeism and sub-optimal productivity. Applying ergonomic principles in the workplace (comprising work, physical and social environment, and workstation design) can prevent most of these problems. This code provides guidance on how to achieve a better quality of working life for staff working in office environments.
Ergonomics is the science of designing work and workplaces to accommodate user’s physical and psychological needs. It aims to minimise users’ limitations and amplify their capabilities. "Office Ergonomics" is the application of ergonomic principles in an office setting. The objective of office ergonomics is to maximise the quality of working life and to minimise the occurrence of WMSD.
By adopting good ergonomics practices, organisations can promote good work habits that will lead to fewer health problems related to poor ergonomics such as muscular aches and pains, visual discomfort and work stress. This is likely to bring about fewer days of absenteeism from work and also lower healthcare costs. All these are likely to promote better work attitudes, higher morale and productivity and better quality work life for office workers.
RECOMMENDATIONS
The Singapore Standard Code of Practice for Office Ergonomics covers the fundamentals of office ergonomics, including physical (e.g design of office equipment and furniture), environmental (e.g inappropriate lighting) and psycho-social (e.g monotonous work) elements. The key recommendations for the set up of the office workstations are as follows:
Work Table
The height of the work surface should be adjustable with an ideal height of 70 cm. There should be enough knee clearance and legroom to allow the worker to stretch out his legs. Equipment on the workstation should be laid out to minimise awkward over-reaching postures. Frequently used items such as your keyboard or mouse, should be within easy reach.
Chair
The chair should be adjustable, stable and provide a good back support. The recommended chair height is between 35 and 50cm. The backrest should be slightly reclined at an angle between 100 and 120 degrees to reduce the pressure on the spine. Chairs should be fitted with five castors for stability and be able to swivel smoothly.
Computers
The monitor should be placed directly in front of the worker. The top edge of the monitor should not be higher than the eye level. Input devices such as keyboard and mouse should be placed at the same level and allow users to adopt a natural hand position.
For extended work, a computer with separate monitor, keyboard and mouse should be used instead of a laptop.
Sitting Work Posture
Sit in a slightly reclined and relaxed position with the back supported and the feet resting comfortably on the floor or foot rest. Avoid sitting in a fixed posture for long periods. Change position, stand up, stretch or walk around whenever you feel tired. Short pauses of 20 to 30 seconds may enhance productivity.
Lighting and glare
Drapes or blinds at windows and skylights could be installed or walls could be treated with neutral tone colours to reduce glare and visual discomfort. In addition, monitors should be placed perpendicular to windows. The user should not sit with either the front or back to the window.
Contributed by: Patrick Ker, Head, Occupational Therapy Department, Singapore General Hospital |
|
The SGH Occupational Therapy* Department has been a provider of rehabilitation services since 1948. It offers rehabilitation services in areas such as upper limb and hand rehabilitation, burns and plastics, neurology, orthopaedics, oncology, mental health therapy, vascular and lymphoedema rehabilitation. The department also provides Workplace Health Programmes and Ergonomics Consultancy Services to Companies. For more information, please call 6326 5325. |
|
* Occupational Therapy is a health profession that uses activities with specific goals to help people of all ages prevent, reduce or overcome effects of disabilities. The fundamental purpose of occupational therapy is to maximise one's functions and quality of life.
REFERENCES
Faucett, J., Garry, M., Nadler, D. & Ettare, D. (2002). A test of two training interventions to prevent work-related musculoskeletal disorders of the upper extremity, Applied Ergonomics, 33 (4), 337-347.
Putz-Anderson, (1988). Cumulative Trauma Disorders: A manual for musculoskeletal diseases of the upper limbs. London: Taylor & Francis.
Silverstein, B.A. & Hughes, R.E. (1996). Upper extremity musculoskeletal disorders at a pulp and paper mill. Applied Ergonomics, 27(3), 189-194.
SPRING Singapore (2005). SS 514: The Code of Practice for Office Ergonomics. Standards, Productivity and Innovation Board. | |
|