Ergonomics is fundamental to creating a comfortable and efficient workplace, yet it is often overlooked until discomfort or injuries arise. Musculoskeletal disorders (MSDs) are common among workers who spend long hours in poorly designed workspaces. Today, we’re focusing on the critical connection between ergonomics and MSDs and how proper ergonomic practices can prevent these issues.
In this post, we’ll delve into the importance of ergonomics, the impact of MSDs on health and productivity, and practical steps you can take to create a more ergonomic work environment. By the end, you’ll be equipped with the knowledge to enhance your workspace and reduce the risk of musculoskeletal disorders.
What You’ll Learn
- Importance of Ergonomics: Understand ergonomics’ crucial role in preventing workplace discomfort and injuries.
- Impact of MSDs: Learn about the common musculoskeletal disorders resulting from poor ergonomic practices and how they affect health and productivity.
- Ergonomic Solutions: Discover practical tips and strategies for creating a more ergonomic workspace, reducing the risk of MSDs, and enhancing overall well-being.
Introduction
Musculoskeletal Disorders (MSDs) are some of the most common occupational injuries. They affect the muscles, bones, joints, tendons, ligaments, or other connective tissue. The topic continues to gain headlines, including a recent announcement of a partnership with the National Safety Council and Amazon (National Safety Council, 2020). However, MSDs were first described in the 1700s and documented through the nineteenth and twentieth centuries as many countries experienced an epidemic of MSDs, or Cumulative Trauma Disorders (CTDs) (Karwowski, 2001, 71).
What is Ergonomics
According to the International Ergonomics Association,
Ergonomics is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and methods to design in order to optimize human well-being and overall system performance.
The term ergonomics is derived from the Greek ergon, meaning work, and nomos, the study of.
As a multidisciplinary field, ergonomics is closely linked to occupational hygiene on many fronts. It links “work” with the individual worker to achieve an optimal operating interface or relationship. Some professions frequently involved in ergonomics are human resource personnel, psychologists, physiologists, engineers, safety practitioners, sociologists, physiotherapists, and medical practitioners.
Ergonomics encompasses issues such as:
- Muscular work and control of movement.
- Work efficiency and process design.
- Anthropometry (study of the measurements and proportions of the human body).
- Heavy work and handling loads (manual materials handling).
- The person-machine interface.
- Mental activity, stimulus, and fatigue.
- Occupational stress.
- Boredom and monotonous tasks.
- Shift work, working hours, and eating habits.
- Vision.
- The physical work environment (lighting, noise, vibration, and climate).
Muscular Work and MSDs
Muscular work concerns muscle strength, the time it takes for muscles to become fatigued, isolation of specific muscles for movement and action, static and dynamic muscular loads, and limitations to muscular work. According to the Bureau of Labor Statistics (BLS), MSDs are common and costly. They are the single largest category of workplace injuries and responsible for almost 30 percent of all workers’ compensation costs.
In the U.S., MSDs (U.S. Bureau of Labor Statistics, 2020) are defined as including:
cases where the nature of the injury or illness is pinched nerve; a herniated disc; meniscus tear; sprains, strains, tears; hernia (traumatic and nontraumatic); pain, swelling, and numbness; carpal or tarsal tunnel syndrome; Raynaud’s syndrome or phenomenon; musculoskeletal system and connective tissue diseases and disorders, when the event or exposure leading to the injury or illness is overexertion and bodily reaction, unspecified; overexertion involving outside sources; repetitive motion involving microtasks; other and multiple exertions or bodily reactions; and rubbed, abraded, or jarred by vibration.
MSDs are generally classified into two main groups: back disorders related to handling weights and upper limb disorders known as “repetitive strain injuries” (IBV, 2017, 6). Upper limb disorders are also work-related upper limb disorders (WRULD).
The disorders progress through several stages, including pain, stiffness, tingling, and numbness. Since muscles consist of motor units containing thick and thin contractile proteins (myofilaments) that slide past one another, enabling muscles to shorten or contract, muscle contraction can be dynamic or static.
Dynamic muscular effort consists of rhythmic contraction, extension, tension, and relaxation. Static muscular work occurs when the muscle contracts for a lengthened period, usually in a postural position. Maintaining a static posture (e.g., sitting in the same position all day, with arms flexed for typing, writing, reading, or meeting people) increases the static load on some muscles. The muscles become shorter and denser, impeding blood circulation, especially in the arms, neck, and shoulders.
Risk Factors for Muscular Work
Risk factors for muscular work generally include force, repetition of movement, posture, coupling, vibration, and temperature. The aspects to consider include:
- Does the task involve forceful movements or exertions?
- Does the task involve lifting or handling materials/
- What characteristics of the tool or equipment affect its grip?
- What posture is adopted (e.g., kneeling, prolonged standing, sitting, twisting, elevation, rotation, deviation from the normal line)
- Are there any mechanical stressors?
- Are there any sources of vibration or exposure to extremes of temperature?
- How often is the task repeated? What is the cycle time?
- Is there any repeated or prolonged stress to the trunk, shoulder, or upper extremities?
Summary
Ergonomics considers the relationship between the worker and work and aims to obtain an optimal fit. Muscular work is a significant contributor to occupational injuries. Both dynamic and static muscular effort need to be considered when understanding the risk for musculoskeletal disorders.
Helpful Resources
- Introduction to Ergonomics and Human Factors, by Robert Bridger
- Fitting the Human: Introduction to Ergonomics/Human Factors Engineering, by Karl Kroemer
- Occupational Noise Management Blog Post, by Megan Tranter
Bibliography
IBV. (2017). Musculoskeletal disorders caused by the most common job demands and ergonomic risks. European Commission. https://ec.europa.eu/programmes/erasmus-plus/project-result-content/c7cc4b4d-52c9-4b5e-a282-46f53f5f5e98/D2.1.MSDs_job_demands_Revised.pdf
International Ergonomics Association. (n.d.). International Ergonomics Association. International Ergonomics Association. https://iea.cc/what-is-ergonomics/
Karwowski, W. (Ed.). (2001). International Encyclopedia of Ergonomics and Human Factors (Vol. 1). Taylor & Francis.
National Safety Council. (2020, June 10). ‘Proactively taking the lead’: NSC, Amazon partner to curb MSDs. Safety & Health Magazine. https://www.safetyandhealthmagazine.com/articles/21329-proactively-taking-the-lead-nsc-amazon-partner-to-curb-msds
U.S. Bureau of Labor Statistics. (2020). Occupational injuries and illnesses resulting in musculoskeletal disorders (MSDs). U.S. Bureau of Labor Statistics. https://www.bls.gov/iif/oshwc/case/msds.htm
