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There are multiple risk factors that can contribute to musculoskeletal injuries from exposure to ergonomic hazards while performing office work at home or in the office. What these risk factors all have in common is that they work to cause musculoskeletal disorders, psychosocial health effects, and reduce the quality of life outside of working hours. Risk factors come from many aspects of the workstation, task, and individual worker. They can be grouped into three main categories which are biomechanical, task-specific, and individual worker characteristics. When conducting an office ergonomic assessment for a workstation and task, the factors mentioned below are what are assessed, and controlled.
Biomechanical risk factors are present when workers perform tasks that require heavy lifting and/or excessive repetition, and awkward or static postures (1). These factors put excessive strain on the tissues of the body. Over time, the accumulated strain can result in an injury or the development of discomfort/pain. What all these factors have in common is that they remove the body from its neutral posture and loads are displaced unevenly throughout the body as a result. For excessive repetition to cause harm it does not require the lifting of heavy objects. Excessive repetition regardless of forces required to perform the movement can cause injury. One of the most common musculoskeletal disorder in the world is Carpal Tunnel Syndrome. Often this injury is associated with repetitive finger movements such as clicking and typing, in combination with compression of the wrist against a work surface. The repetitive motions result in the tissues becoming irritated and then inflamed, once inflamed the space in the carpal tunnel is reduced and the median nerve becomes compressed. The loss of sense and slight reduction in movement is a result of stress on the tissues of the wrist even though the actions require minimal amounts of force to be produced.
Task-specific risk factors include, workstation layout, high physical work, work that has high psychosocial demands, or work that requires prolonged use of visual displays. These factors are more closely associated to the requirements of the tasks being performed by the workers. Workstation layout is extremely important as it is a combination of furniture and organization of materials. A worker using a chair that has very low adjustability and support can remove the worker’s body from a neutral seated posture for extended or short and frequent periods of time. Combining a poorly suited office chair with a desk or work surface that is poorly organized can make the worker reach for items such as a mouse or keyboard. When reaching to use the mouse the worker is then in a static reaching position for a period of time which can put unhealthy stress on the tissues of the shoulder for example. Most of our working time when seated at a desk is spent using some type of visual display, being a cell phone or computer screen. Nowadays, we spend most of our time looking at a screen; without knowing the position of the screen in relation to our body plays a massive role in the risk of a musculoskeletal injury as a result of this.
Often forgotten but extremely important to consider is that workers come in all sizes. Therefore, there is hardly ever a workstation design that is a one-size fits all design. A common phrase to go by when designing a workstation or task setup is to “design it for the worker since you cannot design the worker to the workstation or task”. No two workers are the same thus when ergonomics are considered, individual worker characteristics such as smoking, a high body mass index, anthropometry, and other co-morbidities which include non-occupational related injuries are ergonomic risk factors too (1, 2). These factors are difficult to prevent from being introduced into the workspace, but their effects can be mitigated once identified. A worker’s anthropometry is an extremely important risk factor that must be considered. A workstation for a worker who is 5’2” should differ dramatically from a workstation for a worker who is 5’10”. If the workstation was designed for the taller individual in mind, the smaller worker will be required to reach or lean forward much more frequently for example. When a worker has to reach to perform their task, the risk of injury from exposure to an ergonomic hazard is significantly higher than a worker who does not have to reach to perform the same task.
This list of risk factors for exposure to ergonomic hazards is not fixed, as every situation presents other unique challenges and risks that are identified and assessed on a case-to-case basis. This is why it is extremely important to have objective and competent professionals performing ergonomic assessments.
1. Da Costa BR, Vieira ER. Risk factors for work-related musculoskeletal disorders: a systematic review of recent longitudinal studies. American Journal of Industrial Medicine 53: 285–323, 2010. doi: https://doi.org/10.1002/ajim.20750.
2. Klussmann A, Gebhardt H, Liebers F, Rieger MA. Musculoskeletal symptoms of the upper extremities and the neck: A cross-sectional study on prevalence and symptom-predicting factors at visual display terminal (VDT) workstations. BMC Musculoskeletal Disorders 9: 96, 2008. doi: 10.1186/1471-2474-9-96.