Study Guide: Industrial Ergonomics

BOS-3701

Study Guide: Industrial Ergonomics

In this unit, we will cover some of the basics of ergonomics. You may be asking yourself why you are studying ergonomics in an undergraduate occupational safety and health (OSH) program and how ergonomics can help you in your future career as a safety professional. Hopefully, this will be made clear as you move forward with this unit; you will find that ergonomics is an important aspect of OSH and is frequently addressed by important OSH-related agencies and organizations that safety professionals often turn to for information (National Institute for Occupational Safety and Health [NIOSH], n.d.; Occupational Safety & Health Administration [OSHA], n.d.).

Certainly, human beings are amazing machines, but their bodies do have limits. Consider the following scenario. You are sitting at your kitchen table or in the front seat of your company vehicle while reading and studying the material for this course. You are knee-deep into learning about ergonomics when your back begins to cramp up, or maybe you feel a knot in your neck. These daily aches and pains can be a real nuisance and can significantly hinder one’s productivity, but how does this happen? You were just sitting there for goodness sake! And now you are in pain for apparently no reason! Now, consider such incidents occurring on a much larger scale such as a factory floor where the major muscle groups of many employees, including the legs and back, may be required to remain somewhat motionless for extended periods of time. This causes muscles to remain in a contracted, static position and limits blood flow through the muscles, which can lead to complications (Bush, 2012).

The interaction of people with machinery has come to be known as ergonomics. Fortunately, it is possible to discover a lot of the causes of our discomfort by analyzing man/machine interactions and applying the science of ergonomics to help workers avoid uncomfortable postures and activities that might lead to unnecessary strains and stressors. In the example above, the cause of soreness and pain from sitting in a static position has been identified, and the problem can be easily alleviated by providing employees with an opportunity to get up and move around from time to time. Indeed, requiring an individual to move around a bit can even be incorporated into the job itself without the requirement of a rest break. A person who sits while soldering electronic components, for instance, may be required to get up every so often to get more parts for the operation.

Now that we know a few things about ergonomics, let us consider how the field of study came into being. The application of ergonomic solutions to address human work is not new and has been considered frequently

throughout history, even if it was not labeled as such. For instance, around 500 B.C. in the Greek civilization, craftsmen started using ergonomics in the design of their tools (Stack, Ostrom, & Wilhelmsen, 2016). Additionally, farmers toiling in the fields and working with animals making furrows for their future crops had to think, “There has to be a better way.” And indeed, we see through history that technology in agriculture has resulted in making job tasks associated with the growing of crops much more accommodating to the human body. Please spend some time reviewing the history of ergonomics. It is interesting to learn about some of the people who have helped to grow this field of study and the contributions they have made.

As you can see in reviewing the history of ergonomics, humans have continued to fit the job to the person. This has been helpful for businesses in more than one way. For starters, having an ergonomically ideal workstation can help to enhance productivity and, hence, profitability. If any of you have ever bent over the hood of a car to replace a serpentine belt, change spark plugs, or fix a leak, you will understand why body positioning is important. If you can do a job without feeling pain, then you will be able to perform the job longer and will likely make fewer mistakes. Employee safety and health is clearly another important consideration. It is important to know how the workers’ environment might affect their physical well-being. A loud, noisy environment that requires a full day of repetitive, forceful movements while standing in awkward positions and bending over to retrieve parts can result in some fairly serious occupational injuries and illnesses over time. These injuries and illnesses, such as lower back pain, lower back injuries, damaged rotator cuffs in the shoulder, carpal tunnel syndrome, tendinitis, and tenosynovitis, have come to be labeled as work-related musculoskeletal disorders (WMSDs) (Stack, Ostrom, & Wilhelmsen, 2016).

In addition to enhancing productivity and employee safety, ergonomics can also be a benefit; properly designed workstations can prevent financial devastation to a worker and his or her family. Consider a situation where the main breadwinner working at a poultry plant sustains a case of carpal tunnel syndrome as a result of repetitive, forceful movements over a period of years and can no longer do his or her job. It is important to do what we can to prevent such occurrences not only to ensure profitability but also to prevent the impact of injuries and illnesses sustained by employees.

The third chapter of your textbook discusses the idea of anthropometry, which deals with the measurement of the human body. Humans obviously can differ a great deal with respect to body size, reach, gait, strength, and even how fast they can run or how high they can jump. Consider a married couple: the husband is 6 feet tall, and the wife is 5 feet tall. The couple owns a German sports car that makes automatic adjustments to the driver’s seat, steering wheel, and side mirrors. The car is generally driven by the wife, who is much smaller than the husband. When the husband gets in to drive the car after his wife has driven it, his head hits the door frame, his knees and chest hit the steering wheel, and he cannot see out of the side mirrors before hitting the button to activate the automatic adjustments. The opposite happens when the wife gets in the car after the husband has driven it; she is swallowed up in the car and can barely even reach the wheel. This is just one example of why it is important to consider human variability in the design of workstations.

The idea behind anthropometry is to design the work environment with consideration of the people who are going to use that machine or tool. If we know that most men are between 65 inches and 75 inches in height, we could build a machine based on those standards. But, what if a woman needs to use that machine? Most women are between 55 inches and 65 inches in height. This needs to be considered. Therefore, when we are making measurements of our employees, we have to take into account who is going to use the machine or work at the workstation in question, and we also need to consider that it may be inappropriate to exclude individuals from a given job due to laws related to social equality. Thus, it is not uncommon to have to factor in adjustability and various accommodations to make workstations fit a wide variety of individuals.

As you read through Chapter 3, you will note that there are a lot of tables and graphs. Use them as a reference, but understand the concept behind the 95th-percentile rule and the 5th-percentile rule. Think about the safety constraints that are designed into our everyday world. Recently, there was a terrible example of a failure of the percentile rule. The Cincinnati Zoo had a gorilla enclosure, and the safety features of the outside enclosure were meant to keep everyone out of the enclosure (Ellis & Rose, 2016). These precautions did not prevent a young child from being able to climb into the enclosure, bypassing the safety features. Unfortunately, the gorilla had to be put down to save the child. Had you been the designer of the enclosure’s safety system, would you have designed it to meet only the 50th percentile or the 90th percentile? Even at 100%, was there still a chance that a child could breach the system and become exposed to the dangers of the animal? This is just an example of the importance of considering anthropometry in relation to
public safety.

Obviously, ergonomics pertains to more than just the worker sitting at his or her office workstation and possibly developing carpal tunnel syndrome from typing too much. There is much more to the subject. Read some of the case studies found at the end of Chapter 3, and then consider the workers whom you interact with and the environments they face. Consider ergonomic issues these individuals might encounter in performing their jobs. Consider the work environment and ergonomics of the bus driver, the train operator, the cab driver, the plumber who fixes your toilet, or the electrician who works on your stove. Each of these professionals faces unique work environments that pose unique ergonomics-related challenges.

In closing, take a look at the summary for each chapter, and study the review questions. That is where your unit assessment questions will come from. The answers are there for the taking; use your textbook as the reference it is.

References

Bush, P. M. (2012). Ergonomics: Foundational principles, applications, and technologies. Boca Raton, FL: CRC Press.

Ellis, R., & Rose, R. (2016). Cincinnati Zoo kills gorilla to save child who slipped into enclosure. Retrieved from http://www.cnn.com/2016/05/28/us/zoo-kills-gorilla/

National Institute for Occupational Safety and Health. (n.d.). Ergonomics and musculoskeletal disorders. Retrieved from http://www.cdc.gov/niosh/topics/ergonomics/

Occupational Safety & Health Administration. (n.d.). Prevention of musculoskeletal disorders in the workplace. Retrieved from https://www.osha.gov/SLTC/ergonomics/index.html

Stack, T., Ostrom, L. T., & Wilhelmsen, C. A. (2016). Occupational ergonomics: A practical approach. Hoboken, NJ: Wiley.