**2. Risk factors**

Factors that make a worker prone to developing WMSDs are called risk factors. **Table 1** lists various risk factors associated with WMSDs [**Table 1**. Risk factors for WMSDs]. Risk factors related to office computer work are classified into postural risk factors, environmental risk factors, individual risk factors, psychosocial risk factors, and risk factors associated with duration and intensity of office work.

#### **2.1. Postural risk factors**

Posture is the carriage of a body as a whole, the attitude of the body, or the position of the limbs [14]. The literature showed an established link between MSDs and improper posture at computer workstations [15, 16]. Sauter et al. [17] found that arm discomfort increased when keyboard height was above the elbow level. Chiu et al. [18] reported a significant association between head posture during computer work and neck pain. Eltayeb et al. [19] highlighted the significant associations between irregular "head and body posture" and "neck, shoulder and forearms/hands complaints."

Awkward and prolonged static postures contribute to musculoskeletal discomforts among OCWs. Twisting the torso to reach file cabinets, cradling the phone between the neck and


**Table 1.** Risk factors for WMSDs.

WMSDs have enormous economic implications. The Institute of Medicine estimates that the total economic burden of WMSDs could be as high as \$54 billion annually [10]. Ergonomic injuries related to computer work constitute a significant portion of WMSDs. The US Occupational Safety and Health Administration (OSHA) estimated that employers are "spending \$20 billion a year on worker's compensation costs related to ergonomic injuries and illnesses" [11, p. 106]. Occupational injuries and illnesses have many direct and indirect cost implications. When calculating cost implications of WMSDs, one must give due consideration to all factors. Workers' compensation costs and charges involved in medical care and rehabilitation are considered direct costs, while lost productivity, lost time, training new staff, administrative costs, and temporary staffing are considered indirect costs. Web resources may assist employers to calculate cost implications of occupational injuries. For example, the OSHA Safety Pays website calculates the estimated total costs (direct and indirect) of common work-related injuries

In today's age, computer use has become an integral part of daily life. People use computers for various work-related and non–work-related tasks (social media, banking, shopping, etc.). Office computer workers (OCWs) use computers on an average of 6-12 hours a day [13]. The surge in computer use has also created a surge in computer work-related MSDs. Rehman et al. [8] stated that around 27% of computer users report backaches or discomfort. The chance of sustaining WMSDs is high when computer workers spend long hours on their computers. As the scope of this chapter is limited to the discussion of ergonomics related to the office computer worker population, the following sections review the risk factors related to office computer work, present ergonomics education as an effective intervention for OCWs, and

highlight the role of employers and employees in preventing WMSDs among OCWs.

Factors that make a worker prone to developing WMSDs are called risk factors. **Table 1** lists various risk factors associated with WMSDs [**Table 1**. Risk factors for WMSDs]. Risk factors related to office computer work are classified into postural risk factors, environmental risk factors, individual risk factors, psychosocial risk factors, and risk factors associated with

Posture is the carriage of a body as a whole, the attitude of the body, or the position of the limbs [14]. The literature showed an established link between MSDs and improper posture at computer workstations [15, 16]. Sauter et al. [17] found that arm discomfort increased when keyboard height was above the elbow level. Chiu et al. [18] reported a significant association between head posture during computer work and neck pain. Eltayeb et al. [19] highlighted the significant associations between irregular "head and body posture" and "neck, shoulder

Awkward and prolonged static postures contribute to musculoskeletal discomforts among OCWs. Twisting the torso to reach file cabinets, cradling the phone between the neck and

based on national worker's compensation data of the US [12].

48 Anatomy, Posture, Prevalence, Pain, Treatment and Interventions of Musculoskeletal Disorders

**2. Risk factors**

duration and intensity of office work.

and forearms/hands complaints."

**2.1. Postural risk factors**

shoulder, curved sitting (bending the torso toward the monitor), slouched sitting with legs placed on an object under the work surface, and sitting on a high chair with dangling feet are some examples of awkward postures during office computer work. Postures with elevated or abducted shoulders are also considered awkward postures. These postures, when sustained, strain the lower back, shoulders, and neck muscle groups.

As computer workers often engage in tasks that demand high level of concentration, they get absorbed in their work and assume a given posture for long periods of time. During prolonged static sitting, the muscles that sustain body posture undergo a prolonged state of contraction, leading to decreased transportation of sugar and oxygen to dynamically contracting muscles. This causes an accumulation of waste products such as lactic acid and carbon dioxide in those muscles, leading to muscle spasms and fatigue. Prolonged sitting also contributes to myriad health issues such as low back pain [20], coronary artery disease, and kidney disease [21].

#### **2.2. Environmental risk factors**

Poor work environments augment the risk of WMSDs. Office work environments that are not conducive to their users can be referred to as "poor work environments." For instance, a workstation where the keyboard and mouse are placed at different levels, causing the user to elevate/abduct shoulders can be considered a poor workstation. A workstation without adjustable components (work surface, office chair, etc.) and necessary accessories (hands-free phone, document holder, etc.) can also be construed as a poor work environment. Further, environments with the heightened noise level, increased glare, and extreme temperatures are considered as poor work environments.

#### **2.3. Individual risk factors**

A computer worker may also become prone to developing WMSDs due to personal factors such as health history and poor work behaviors. Individual-related factors contribute to WMSDs through their effect on body structure, function, and posture. Some of the individual-related risk factors are obesity, pregnancy, arthritis, trauma, and endocrinal disorders. Working without rest breaks, binge working, ignoring the body's warning signs such as pain and discomfort, ignoring flexibility/stretching exercises, failing to alternate work tasks, following poor working techniques, and failing to adjust workstation components as needed are the examples of some maladaptive work behaviors.

alone cannot reduce or prevent musculoskeletal injuries. For instance, a lot of computer workers sit on adjustable chairs without adjusting them due to lack of knowledge. Similarly, though many computer users know that bad posture is a risk factor, they continue to assume awkward and risky postures. Hence, to prevent WMSDs among OCWs and ensure their well-being, it is critical to educate them on "ergonomics" and "risk factors associated with WMSDs." An

Ergonomics Education for Office Computer Workers: An Evidence-Based Strategy

http://dx.doi.org/10.5772/intechopen.72221

51

Ergonomics means the science of fitting the job to the worker. In the context of office computer work, it refers to the computer user-workstation fit. Interventions that aim to enhance this fit are called ergonomic interventions. Ergonomic interventions differ from traditional therapeutic interventions because they target work posture, work habits, behaviors, and the environment [31]. They range from modifying workstations to long-term educational interventions

Ergonomics is a recognized intervention strategy. Several occupational health and safety agencies across the world advocate for ergonomics. Many mid- and large-size technology companies offer ergonomic training to their employees as ergonomic interventions have been

One of the well-documented ergonomic interventions is ergonomics education [30, 32, 33]. Ergonomics education is a strategy in which an ergonomic expert educates participants (workers) on ergonomic principles [see **Table 2**. Key ergonomic principles] and other necessary ergonomic information either on-site or virtually. The aim is to enhance participants' knowledge on WMSD risk factors, WMSD prevention strategies, and effective work behaviors. There are two primary objectives for any ergonomics education program. One is to help participants become aware of the risk factors and the other is to encourage participants to

found to enhance productivity, improve worker well-being, and reduce WMSDs.

Adequate clearance Computer workers must have adequate thigh/knee clearance under their desk.

occasionally used items within arm's distance.

Minimize fatigue Computer workers must avoid prolonged work and sustained posture.

chair, are adjustable.

and hard surfaces.

at work.

heights.

Adjustability Computer workers must ensure that their workstation components, including the office

Work in good posture Computer workers must be mindful of their posture and assume the ideal work posture

Work at proper heights Computer workers must adjust the workstation and chair as necessary to work at proper

Computer workers must keep frequently used items within forearm's distance and

Computer workers must avoid resting their forearms/hands/thighs against sharp edges

evidence-based strategy to impart this education is *Ergonomics Education* [13, 30].

**4. Ergonomics education**

modify their work behavior.

**Table 2.** Key ergonomic principles.

Keep things within

Minimize direct pressure

reach

with the aim of preventing and/or treating WMSDs.

Gender has also been hypothesized as a risk factor. The literature reveals that women are at a relatively higher risk than men [22, 23]. This could be due to differences in anthropometrics and physiology in women. Also, women often assume responsibilities of non–work-related activities such as household tasks, which may add to muscle strain and make them more vulnerable to WMSDs.

#### **2.4. Psychosocial risk factors**

Psychological variables such as work pressure and job strain may also contribute to WMSDs. Hannan et al. [24] found a correlation between increased job strain and neck musculoskeletal symptoms. Perceived inadequate support from managers, low level of control, and information overload were also identified as psychosocial risk factors in the literature. With information overload, a worker spends an increasing amount of time using electronic gadgets and ignores proper work posture, thereby developing his/her risk for WMSDs. Mental stress can also augment the physical load during computer work because a computer worker with mental stress may exert more force on mouse or keyboard [25].

#### **2.5. Risk factors associated with duration and intensity of work**

Working on computers for long hours is a risk factor. The literature reveals a correlation between the duration of computer use and upper extremity (UE) pain, back pain, and eye strain [26]. Repetitive hand, wrist, and finger movements (e.g., typing for extended periods of time), speedy/jerky movements, and force applied while typing may also contribute to UE pain and musculoskeletal discomforts [25]. The demand for productivity and time pressure in today's work culture demand increased keying and extended hours of work from OCWs, thereby making them susceptible to WMSDs. Repetitive motions result in the vasoconstriction of arteries causing ischemic injury and edema due to anoxic damage [27].
