The Complete Guide to Ergonomics

The Complete Guide to Ergonomics
Two workers lifting a box

What is Ergonomics?

The International Ergonomics Association defines ergonomics as: “…the scientific discipline concerned with the understanding of interactions among humans and other system elements, and the profession that applies theory, principles, data and methods to design to optimize human well-being and overall system performance.” (1)

“Ergonomics is a science-based discipline. It brings together knowledge from anatomy and physiology, psychology, engineering, and statistics and ensures that the designs complement the strengths and abilities of people who use [them].” (2)

While the definition is informative, several implications in these statements need clarification.

  1. The above “ergonomic” definitions imply that one discipline or one profession engages in the practice of ergonomics. Many disciplines practice ergonomics. You will see this in the discussions below.
  2. Both definitions emphasize ergonomic design, which is undoubtedly the core element in adapting the workplace to the worker. However, the statements seem to ignore the importance of training employees to use ergonomic work principles as they work. Even the most ergonomically designed workplace won’t help if used improperly.

Ergonomics, by definition, encompasses the study of how humans interact with their environment and tools. Research continues to expand our understanding of what ergonomics means, especially in the workplace.

Ergonomics is an ongoing process. It is not a “one-and-done” project. As such, it is best carried out by teams that meet regularly to discuss current and future assessments.

It begins with a risk assessment. Next, it’s followed by the development and implementation of interventions (also known as countermeasures or abatements). Finally, it ends with the evaluation of the improvement.

Many ergonomic solutions are implemented in a limited scope, initially as a trial. If the trial proves successful, the project is expanded as appropriate throughout the organization.

Risk assessments are typically driven by the injury incidence associated with a particular job function. Solutions must be developed in collaboration with operations and with the support of all levels of management. Otherwise, change adoption may be negatively affected. Management typically wants to see a potential investment return to justify the corporate expenditure.

What are the Benefits of Ergonomics?

Ergonomics benefits employers and employees alike in 3 important ways:

  1. An ergonomically designed workplace with employees using the best ergonomic practices makes the employee more comfortable and increases job satisfaction.
  2. Ergonomically designed workplaces decrease the frequency and severity of ergonomic-related musculoskeletal disorders (MSDs)
  3. Together, increased comfort and fewer MSDs improve productivity.

What is the History of Ergonomics?

A detailed history of ergonomics could form the basis of several blogs. Instead, what follows is a summary.

The term “ergonomics” wasn’t officially coined until 1950 in the UK. Shortly thereafter, the US formed the Human Factors Society in 1957. However, the practice of ergonomics goes much further back than the mid-twentieth century. The term “ergonomics” is derived from the Greek words “ergon,” meaning work, and “nomos,” meaning natural law.

Hippocrates (fifth century B.C.) described the arrangement of a surgeon’s workspace using ergonomic principles. Even in agrarian societies, farm tools were gradually improved to increase the ease and comfort of use.

The Industrial Revolution (mid-19th century) ushered in large-scale manufacturing. Many of the manufacturing processes were based on ergonomic principles. (3).

World War II increased interest in ergonomics. The interactions between man and machine became exponentially more complex and required improved coordination and response time.

Initially, even the best-trained pilots experienced difficulties that caused loss of life and expensive aircraft. These challenges generated a new set of controls and displays that decreased pilot error. (3)

In the years following WWII, the space program created new challenges for human factors. These factors included weightlessness and extreme gravitational forces.

The advent and subsequent growth in computer use changed office workspace design. It evolved as a primary component of modern-day ergonomics. (3)

Today, ergonomics in the workplace addresses a combination of office and industrial environments. It also includes the use of mobile devices as a primary work tool in many environments.

What is the difference between Ergonomic Standards and Ergonomic Guidelines?

A great deal of confusion exists between the terms “standard” vs. “guidelines.” Generally, a “standard” is associated with a set of more rigid rules that must be enforced. In contrast, a “guideline” designed to provide a best practice approach.

In 2001, under the Clinton administration, OSHA issued an official “Ergonomics Program Standard.” However, it was quickly repealed by the Bush administration a few months later. Today, ergonomic programs are governed under OSHA’s General Duty Clause, Section 5(a)(1). This law states that employers must maintain a work environment free from recognized serious hazards, including ergonomic hazards.

Instead of an ergonomic standard, OSHA has published numerous guidelines for ergonomics in the workplace. These guidelines cover a variety of industries ranging from nursing homes to shipyards.

These guidelines serve as a valuable resource for employers, safety professionals, and ergonomic consultants. They detail industry-specific hazards and suggest countermeasures to address them. Each “Guideline” references any best practices documents, relevant training, and regulations related to that type of work.

OSHA’s general guidelines for ergonomic programs recommend that the following elements be included:

  • Promote management support of the program.
  • Define clear goals and objectives.
  • Assign responsibilities to designated employees.
  • Directly engage employees.
  • Proactively identify ergonomic hazards.
  • Implement solutions to reduce or eliminate hazards.
  • Evaluate changes for continued improvement.
  • Encourage employees to report early discomfort.

Although specific ergonomic standards do not exist, OSHA’s publications on ergonomics clearly show that ergonomics is a top priority.

How is Office Ergonomics Different from Industrial Ergonomics?

When someone asks me if I perform ergonomic assessments, I first clarify if they mean office or industrial ergonomics. Some key differences exist – namely, the type of assessment tools required, and the specific reports generated.

Office Ergonomic Assessments: Key Evaluation Parameters

Office Ergonomic Assessments primarily evaluate the office worker's postures, both static and dynamic postures. These are relative to their computer screen, keyboard, mouse, and chair.

The goals are for the worker to:

  • Achieve a neutral position of the head and neck (with respect to flexion/extension, rotation, and side-bending.
  • Have elbows supported on the armrest of the chair, which is level with the keyboard.
  • Keep the back supported by the back of the chair in a neutral position.
  • Feet supported on the floor or footrest with the hip in < 90 degrees flexion.
  • Maintain the wrists in neutral (relative to flexion/extension) or slight extension.
  • Limit shoulder flexion to about 30-45 degrees when using a keyboard or mouse.

The assessment forms are primarily checklists. They document the presence or absence of these parameters and list areas for improvement. Some evaluators recommend the generic types of equipment needed. Others, if requested, will recommend specific makes and models of equipment.

Office Ergonomic Countermeasures/Solutions

The primary office ergonomic countermeasures include:

  • adjustable-height work surfaces
  • ergonomic keyboards and mice
  • telephone headsets (to avoid excessive lateral bending of the neck)
  • adjustable-height monitors
  • new office chairs
  • sit-stand option

Sometimes, no new equipment is needed. Proper positioning and utilization of the existing equipment are adequate for solving the problem.

A common example is a computer workstation where the monitor sits off to one side rather than directly in front of the user. In this example, the user must maintain a twisted neck to see the monitor. Eventually, this causes neck pain, headaches, or temporomandibular problems in the long term.

The fix is simple: move the monitor directly in front of the user. Also, position the height so that the head and neck are maintained in neutral for viewing.

There are computer programs that allegedly help the worker make his/her/their own workstation adjustments. After all, not everyone has access to an in-person office ergonomics evaluation. However, in this author’s opinion, assessing one’s own workstation is extremely difficult.

At the very least, a coworker can snap some photos or take some videos. This gives the worker an objective viewpoint of their current setup.

Another alternative for some organizations is to conduct remote office ergonomic assessments. The office worker answers a set of questions, measures certain prescribed heights and distances, and sends photos and videos. A remote ergonomics evaluator then compiles the data and makes recommendations.

Industrial Ergonomic Assessments: Key Evaluation Parameters

Industrial ergonomics assessments are significantly different from office ergonomic assessments. Instead of looking exclusively at the relationship between worker and equipment, the evaluator now examines:

  • movement
  • whole-body positioning
  • materials handling
  • task repetitions
  • durations

The height of the workstation in the industrial setting may be a problem. Changing it can be more difficult because the change in one location can affect other areas of the plant or related processes. It may also be magnitudes more expensive than adding height to an office worktable or a footstool.

Industrial work also requires more variety in tool/equipment use. In the office setting, regardless of the nature of the office work, the tools of the trade are similar:

  • keyboard
  • mouse
  • monitor
  • telephone
  • office chair

In one industrial job, however, they may use screwdrivers and welding apparatuses. In another industrial setting, it’s pallet jacks and forklifts. In some jobs, the position used to perform the job is varied.

Other jobs that occur in more confined or restricted areas won’t allow optimal positioning. In some cases, tools can be modified. In other cases, tool modification is too difficult or expensive.

Depending on the type of task being evaluated, various assessment tools have been deployed for industrial ergonomic assessment. A few of the more commonly used assessments include:

  • The Rapid Entire Body Assessment (REBA): provides an entire body posture assessment.
  • Rapid Upper Limb Assessment: provides an upper body posture assessment.
  • Revised NIOSH Lifting Equation: provides a safe lifting weight calculation, given the parameters of a specific lift.
  • WISHA Lifting Calculator: another lifting calculator developed by the Washington State’s Department of Labor and Industries. WISHA is based on NIOSH research. It is used to identify lifting tasks that should be analyzed further using the more comprehensive NIOSH Lifting Equation.
  • Revised Strain Index: assesses the risk of developing a repetitive injury of the hands and wrists.

The Snook Tables (also known as the Liberty Mutual MMH Tables) provide weight/force values for manual materials handling tasks. These tasks include lifting, carrying, pushing, and pulling. The values reflect what is considered acceptable for a percentage of the population.

Industrial Ergonomics Countermeasures/Solutions

In industrial ergonomics, there is a well-known hierarchy of effectiveness for ergonomic countermeasures. See Figure 1(below).

Figure 1. Hierarchy of effectiveness of ergonomic countermeasures.

Personal Protective Equipment (PPE) is only as effective as the people who wear it. PPE includes hard hats, hearing protection, safety glasses, and steel-toed shoes. Effectiveness is totally reliant on the employee's cooperation and is in the employee’s control. Thus, it is the least effective of all countermeasures and is at the bottom of the effectiveness scale

Next to the bottom of the upside-down pyramid are “Administrative” controls. These involve strategies such as training employees in the best lifting techniques. They also involve implementing a job rotation plan to minimize each employee's exposure to the hazard.

It’s a bit easier to achieve consistency of implementation with job rotation. However, with a workforce shortage, this may be difficult. Even the most carefully planned job rotation will be abandoned in the spirit of productivity.

The effectiveness of training depends on the employee’s ability to implement the new techniques learned. It also depends on their motivation to do so to improve ergonomics in the workplace.

It’s very difficult to substitute new behaviors for lifelong habits, especially with lifting or postural habits. Some employees don’t have the strength, flexibility, or balance to perform the job in the preferred manner.

A good example is asking employees to perform to lift by bending their knees instead of at the waist to pick up a load. Some employees lack the flexibility in their knees and ankles to do a squat lift. Others lack the strength in their quadriceps and gluteal muscles. Still others lack the balance required to perform this successfully.

Engineering, Substitution, and Elimination are the most effective countermeasures because they significantly reduce or eliminate the ergonomic hazard. If a process can be engineered differently or eliminated, or if another process can be substituted for the hazardous task, the countermeasure typically produces more lasting, effective, and meaningful change.

Unfortunately, these changes are extremely expensive in some situations, requiring a capital investment. In addition, an engineering change in one part of an organization often has a ripple effect on other parts. Given the complexity and expense of these projects, approval and coordination are required. This involves operations, engineering, and the C-suite approval of ergonomics in the workplace.

Technology that Augments Ergonomic Assessment and Training

Despite having “rapid” in their title, most traditional industrial ergonomic assessment tools require considerable time to use and calculate risk scores. More recently, AI ergonomic risk assessment technology that employs computer-aided video has greatly enhanced the efficiency and accuracy of these assessments.

See Figure 2 below. Some of the software platforms can quickly calculate REBA, RULA, the NIOSH lifting equation, and the RSI. They can do this in a matter of minutes with video capture and minimal manual input.

Figure 2.
figure2

The software calculates an overall risk score and identifies a risk score for each body part. From the body part scores, the user can identify the limb segments that, if addressed, would most improve the overall risk score. The evaluator must develop feasible ergonomic solutions, but the software provides guidance regarding the direction of the intervention.

The technology can also be used for ergonomic training. Most workers are affected by seeing their body position in the video and the related risk scores. If they’re asked to repeat the task using improved work practices, they can see how the scores change.

The visual feedback makes the ergonomic training more meaningful. It also engages the worker in the training process in ways verbal feedback alone cannot.

Another challenge with training is making new techniques into habits. Wearable sensor technology can greatly assist in reinforcing training for ergonomics in the workplace. (See Figure 3. below) The wearable sensor is typically worn on the back or at the waist and acts like an “always there” ergonomic coach.

When bending during lifting exceeds safe levels, workers receive a haptic (vibration) signal. Both the worker and supervisor receive reports that identify the unsafe move. Over time, the number of unsafe moves performed during a shift should decrease.

Supervisors and managers can see which workers are improving and which ones need extra help over time. The technology can also identify work areas that are especially challenging. They may need another ergonomic countermeasure beyond lift training.

Figure 3.
figure3

Who performs ergonomic assessments?

A variety of avenues lead can to a practice in ergonomics.

Certified Professional Ergonomist (CPE). To become certified through the Board of Certification in Professional Ergonomics, one must have a Graduate Degree (MS, PhD) in Human Factors/ Ergonomics. The alternative is a Bachelor’s degree and 24 semester hours covering the topics listed in Figure 4 below. This must be followed by three years of full-time work experience, work samples, and passing a certification exam.

Figure 4.
figure4

Health and Safety Professionals (Physical and Occupational Therapists, Physical and Occupational Therapist Assistants, athletic trainers, exercise science professionals, safety managers, risk managers, and nurses) can develop a specialization in ergonomics through continuing education courses that typically last from 1 to 5 days. Some of these courses also offer certifications, such as the Certified Ergonomic Assessment Specialist (CEAS) offered through the Back School of Atlanta.

Naturally, none of these continuing education courses are as rigorous as the CPE offered through the BCPE described above. However, much of the practical ergonomics that occurs in the field is performed by individuals who are health and safety professionals. They have less academic preparation but a great deal of practical field experience.

How do we know that ergonomics works?

Obviously, ergonomic assessment and training involve certain costs. So, the question becomes: Does it really work? Does it save employers money? Evidence suggests that it does.

But first, let’s consider the true costs of a workplace musculoskeletal injury. Many don’t realize that the total costs must include both direct and indirect costs. Direct Costs include the obvious, easy-to-calculate expenses.

  • Insurance premiums (if insured)
  • Medical expenses (if self-insured)
  • Lost wages

The list of indirect costs is much more extensive and includes:

  • Lost productivity
  • Lost and restricted duty days
  • Time spent at medical visits and rehab
  • Time spent traveling to and from medical visits/rehabilitation
  • Reduced performance of the injured worker after return to work
  • Cost of overtime or temp employees to pick up slack of injured worker
  • Time lost by non-injured workers
  • Reduced output of replacement employee(s)
  • Supervisor time spent managing the injury
  • Safety professional time spent in injury investigation
  • Human resources time spent managing the injury
  • Damage to equipment and/or materials (6)
  • Legal expenses related to workers' compensation lawsuits

OSHA estimates the direct-to-indirect cost ratio ranges from 1:1.1 to 1:4.5. This depends on the cost of the injury (7). The true costs of injuries can be grossly underestimated if only the more easily calculated direct costs are used.

The table below shows the sales volume needed to offset the cost of an injury at different profit margin levels. (8) A company operating at a 2% profit margin would have to increase sales by $500,000 to pay for a $10,000 injury (.02 x 500,000 = 10,000).

figure5

Given the cost of work-related injuries, cost reduction is key.

Peer-reviewed published research proves ergonomics reduces or eliminates the risk factors associated with occupational injuries and reduces injury-related costs.

A research review published in 2008 examined 18 case studies, most of which were published by the National Safety Council.

The studies showed an average increase of 66% in productivity, 44% in quality, 82% in safety records, and 71% in cost benefits. In some cases, it took only 8 months to obtain a payback of monetary investment in the safety initiative. (4) The return-on-investment ranged from 2:1 to 10:1. (5)

Another literature review published in 2010 showed the financial benefits of ergonomic changes in many sectors. (12) The ergonomic changes included worker ergonomic training, equipment redesign, and work reorganization. In the administrative and support sector, changes focused on workstation equipment and training for office workers.

Mechanical patient lifts, and participatory ergonomic teams were used in health care. Ergonomic interventions in the manufacturing and warehouse sectors ranged from engineering controls to educational programs. Regardless of the specific changes, in all sectors, they found strong evidence in support of a financial return on investment because of ergonomic interventions.

Additional individual studies lend support to the cost-effectiveness of ergonomics. In one study, a robotic palletizer that replaced a warehouse manual material handling task cost $300,000.00, increased productivity, and decreased back injury claims, creating a 6% return on investment in just 3 years. (9)

A large electrical utility company implemented a battery-operated press and cutter, recouping its investment in 4 months. (10) Ergonomic changes in an assembly line at a circuit manufacturer created an annual return on investment of 73%. (11)

The bottom line is that ergonomics works. It prevents injuries, saves money, and reduces pain and suffering.

The Role of Ergonomics within the Full Scope of MSD Prevention

The exciting news is that ergonomic assessment and training are important components of even more comprehensive workplace MSD prevention. Additional programs that compliment ergonomics include:

Pre-Hire/Post-Offer Physical Abilities Testing (PAT) and Job Analysis

Pre-Hire/Post-Offer Physical Abilities Testing helps employers hire employees who are physically capable of performing their jobs. If employees have this baseline physical ability, ergonomic training is much easier to implement. Under the Equal Employment Opportunity Commission (EEOC) and the Americans with Disabilities Act (ADA), these tests need to be job-specific. A thorough job analysis is needed to provide the basis for defensible testing to implement ergonomics in the workplace.

Ramp-In/­­Work Acclimation for New Employees

In today’s sedentary society, many employees take jobs they are not physically conditioned to do. Even if they can handle the physical requirements during a pre-hire test, it’s optimal for them to work gradually.

The should work up to sustaining the full workday to adjust to ergonomics in the workplace. While they acclimate to the job, the ramp-in process creates an opportunity to provide ergonomic training. The training gets the employee off to a good ergonomic start.

OSHA-Compliant Early Intervention

Once hired and trained, early MSD symptoms can be addressed with an OSHA-compliant Early Intervention Program (EIP). With this program, employees self-identify as having discomfort. An onsite EIP practitioner (typically an athletic trainer or physical or occupational therapist) provides first-aid treatments relevant to the musculoskeletal system that are approved by OSHA. And the EIP program creates another opportunity to review ergonomic best practices with the employee.

Return-to-Work Testing and Work Conditioning

When a lost-time injury occurs, the question eventually becomes: When can the employee return to work? A return-to-work physical abilities test can be used to determine the worker’s ability to perform the physical requirements of the job.

If the worker fails the return-to-work test, a few weeks of work conditioning typically resolves the issue. It makes reinjury much less likely. During the work conditioning program, ergonomic best practices can be reviewed. This helps reduce the chances that the injured worker does not become a “frequent flyer” on the workers' compensation logs.

Ergonomic assessment and training play a key role in injury prevention and recovery at every step of this comprehensive hire-to-retire injury prevention program.

Contact us to learn more about incorporating ergonomics into your injury prevention program.

  1. Dul J, Bruder R, Buckle P, Carayon P, Falzon P, Marras WS, Wilson JR, van der Doelen B. A strategy for human factors/ergonomics: developing the discipline and profession. Ergonomics. 2012 Apr 1;55(4):377-95.
  2.  Bridger R. Introduction to ergonomics. Crc Press; 2008 Jun 26.
  3. https://www.researchgate.net/publication/323799059_Ergonomics_and_Musculoskeletal_Issues
  4. https://onlinelibrary.wiley.com/doi/abs/10.1002/hfm.20106
  5. https://www.coeh.berkeley.edu/the-economics-of-ergonomics#:~:text=The%20direct%20benefit%2Dto%2Dcost,impact%20on%20quality%20and%20profit.
  6. https://www.researchgate.net/profile/David-Douphrate/publication/237386909_THE_ECONOMICS_AND_COST_JUSTIFICATION_OF_ERGONOMICS/links/56a397dd08aef91c8c12c1fc/THE-ECONOMICS-AND-COST-JUSTIFICATION-OF-ERGONOMICS.pdf
  7. https://www.osha.gov/safetypays/estimator
  8. http://www.Ini.wa.gov/wisha/regs/ergo2000/CBA.
  9. Rodrigues, Clarence C., Ergonomics to the Rescue – A Cost-Justification Case Study, Professional Safety, American Society of Safety Engineers, 2001.
  10. Seeley, Patricia, A. and Richard W. Markin, Business case for implementing two ergonomic interventions at an electrical utility, Applied Ergonomics, 2003 (34): 429-439.
  11. Yeow, P.H. P. and R. N. Sen, Productivity and quality improvements, revenue increment and rejection cost reduction in the manual component insertion lines through the application of ergonomics, International Journal of Industrial Ergonomics, 2006, 36:367-377.
  12. Tompa, Emilie, et. al., A Systematic Review of Workplace Ergonomic Interventions with Ergonomic Analysis, Journal of Occupational Rehabilitation, 2010, 20:220-234.
Picture of Deborah Lechner

Deborah Lechner

Deborah Lechner, ErgoScience President, combines an extensive research background with 25-plus years of clinical experience. Under her leadership, ErgoScience continues to use the science of work to improve workplace safety, productivity and profitability.
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