Ergonomic Exposures

Obesity a Missing Factor in Ergonomics

A Texas A&M study concludes that effective ergonomic guidelines must take BMI into account.
By: | July 28, 2017 • 4 min read
Topics: Safety | Workers' Comp

New research is showing how obesity can impact workers’ capacity to perform certain tasks, highlighting the need to rethink and redesign the tools and methods being used to establish ergonomic guidelines.


As it stands now, the ergonomic tools and procedures in place to safeguard worker behavior and safety were designed using worker populations that tended to be more fit, said Ranjana Mehta, assistant professor at Texas A&M University in College Station, Texas, and lead author of the study, “Relationship Between BMI and Fatigability Is Task Dependent,” in the journal Human Factors.

When we look at how they are designed, most take into account work parameters, such as how heavy the load a worker may be lifting, and how often they may be doing it each day,” Mehta said.

Ranjana Mehta, assistant professor, Texas A&M University

“These tools can then help compare the demands of the work tasks with the worker’s capacity, such as their strength, endurance, and range of motion. These comparisons can provide some insight on the risks these work activities may pose on the workers.”

However, worker capacity can differ based on several personal factors, such as age, gender, and obesity, she said. While some ergonomic tools have been developed or later revised to account for gender and age, none have addressed obesity.

Most of the worker capacity and tool development studies — some as old as three decades — were based on small sets of worker pools, with little to no information on the fitness of the workers involved in the studies, Mehta said.

While some ergonomic tools have been developed or later revised to account for gender and age, none have addressed obesity.

A majority of data on strength and range of motion are based primarily on young male military personnel, and those are outliers for the working population as it stands today.

We are now experiencing an obesity epidemic, and so we have to think in terms of the demands of work and the worker’s capacity to do that work — and how that capacity is altered now that two-thirds of the working population are overweight and obese,” she said.

The study by Mehta and her team, along with University of Buffalo researchers, found that normal-weight subjects had higher endurance on grip, shoulder flexion and trunk extension tests compared with the individuals who were overweight or obese.

These results show that obesity has a substantial negative effect on muscular endurance, particularly in the large postural muscles of the shoulder and the lower back, and that the effects were most significant at lower work-intensity levels — all of which points to a need for ergonomics research to focus more on overweight and obese individuals in the workforce.

“This research was the first step toward strengthening the rationale to create a new database of worker capacity, so that new ergonomic tools can be developed and existing ergonomic tools can be revised,” Mehta said.

Scott Smith, leader of Aon’s Ergonomics practice in Irvine, Calif., said that it’s also challenging to use 1980s-era ergonomics assessment methods — developed and validated on a much younger workforce — because the population has aged, in addition to many becoming obese.

Scott Smith, Ergonomics practice leader, Aon

“Tools like the 91 NIOSH Lifting Guideline are over 20 years old and some parameters like horizontal distance are difficult to apply to workers that are overweight or obese,” Smith said.

For example, the 91 NIOSH lifting guideline states that the maximum horizontal distance that a person should keep a box away from their midsection is 25 inches, Smith said. However, a person with a 40-inch waist or more may not be able to keep a box 25 inches away from their midsection.

However, there are more advanced biomechanical computer models for material handling type assessments in which companies can input specific height and weight for a single person, and that can provide a more specific analysis of how lifting something affects that person, he said.

“With a biomechanical model, a company can determine the specific risk profile for a person with a body mass index less than 20, and another risk profile for person that has the same height, but with a BMI of over 30,” he said.

Biomechanical models, like the one developed by the University of Michigan Center for Ergonomics, are readily available for a cost, Smith said. However, the challenge is that biomechanical models are just a snapshot in time, a static model.

“What these researchers are trying to look at are the dynamic effects of obesity on muscle forces, which is what workers are really doing — they don’t work in a static model, but more dynamically,” he said.


“There’s a need to look at how we address changes in risk factors and workstation design guideline issues that haven’t been addressed in the last 30 years, not just for the obese, but also the aging population.”

The ergonomics group at Aon has developed and uses updated ergonomics assessment tools and advanced Human 3D CAD software programs to assist clients in understanding these types of risk factors as well as at-work ergonomics program activities to resolve issues that have led to soft-tissue workers’ comp claims, Smith said.

“Aon’s team works with our clients to become more proactive with ergonomics to prevent soft tissue injuries, by leveraging more of a human performance approach to employee safety — versus a reactive approach that only addresses current injuries and their costs,” he said.

Katie Kuehner-Hebert is a freelance writer based in California. She has more than two decades of journalism experience and expertise in financial writing. She can be reached at [email protected]

More from Risk & Insurance

More from Risk & Insurance

Risk Report: Marine

Crewless Ships Raise Questions

Is a remote operator legally a master? New technology confounds old terms.
By: | March 5, 2018 • 6 min read

For many developers, the accelerating development of remote-controlled and autonomous ships represents what could be the dawn of a new era. For underwriters and brokers, however, such vessels could represent the end of thousands of years of maritime law and risk management.

Rod Johnson, director of marine risk management, RSA Global Risk

While crewless vessels have yet to breach commercial service, there are active testing programs. Most brokers and underwriters expect small-scale commercial operations to be feasible in a few years, but that outlook only considers technical feasibility. How such operations will be insured remains unclear.

“I have been giving this a great deal of thought, this sits on my desk every day,” said Rod Johnson, director of marine risk management, RSA Global Risk, a major UK underwriter. Johnson sits on the loss-prevention committee of the International Union of Maritime Insurers.

“The agreed uncertainty that underpins marine insurance is falling away, but we are pretending that it isn’t. The contractual framework is being made less relevant all the time.”

Defining Autonomous Vessels

Two types of crewless vessels are being contemplated. First up is a drone with no one on board but actively controlled by a human at a remote command post on land or even on another vessel.

While some debate whether the controllers of drone aircrafts are pilots or operators, the very real question yet to be addressed is if a vessel controller is legally a “master” under maritime law.


The other type of crewless vessel would be completely autonomous, with the onboard systems making decisions about navigation, weather and operations.

Advocates tout the benefits of larger cargo capacity without crew spaces, including radically different hull designs without decks people can walk on. Doubters note a crew can fix things at sea while a ship cannot.

Rolls-Royce is one of the major proponents and designers. The company tested a remote-controlled tug in Copenhagen in June 2017.

“We think the initial early adopters will be vessels operating on fixed routes within coastal waters under the jurisdiction of flag states,” the company said.

“We expect to see the first autonomous vessel in commercial operation by the end of the decade. Further out, around 2025, we expect autonomous vessels to operate further from shore — perhaps coastal cargo ships. For ocean-going vessels to be autonomous, it will require a change in international regulations, so this will take longer.”

Once autonomous ships are a reality, “the entire current legal framework for maritime law and insurance is done,” said Johnson. “The master has not been replaced; he is just gone. Commodity ships (bulk carriers) would be most amenable to that technology. I’m not overly bothered by fully automated ships, but I am extremely bothered by heavily automated ones.”

He cited two risks specifically: hacking and fire.

“We expect to see the first autonomous vessel in commercial operation by the end of the decade. Further out, around 2025, we expect autonomous vessels to operate further from shore — perhaps coastal cargo ships. For ocean-going vessels to be autonomous, it will require a change in international regulations, so this will take longer.” — Rolls-Royce Holdings study

Andrew Kinsey, senior marine risk consultant, Allianz Global Corporate & Specialty, asked an even more existential question: “From an insurance standpoint, are we even still talking about a vessel as it is under law? Starting with the legal framework, the duty of a flag state is ‘manning of ships.’ What about the duty to render assistance? There cannot be insurance coverage of an illegal contract.”

Several sources noted that the technological development of crewless ships, while impressive, seems to be a solution in search of a problem. There is no known need in the market; no shippers, operators, owners or mariners advocate that crewless ships will solve their problems.

Kinsey takes umbrage at the suggestion that promotional material on crewless vessels cherry picks his company’s data, which found 75 percent to 90 percent of marine losses are caused by human error.


“Removing the humans from the vessels does not eliminate the human error. It just moves the human error from the helm to the coder. The reports on development by the companies with a vested interest [in crewless vessels] tend to read a lot like advertisements. The pressure for this is not coming from the end users.”

To be sure, Kinsey is a proponent of automation and technology when applied prudently, believing automation can make strides in areas of the supply chains. Much of the talk about automation is trying to bury the serious shortage of qualified crews. It also overshadows the very real potential for blockchain technology to overhaul the backend of marine insurance.

As a marine surveyor, Kinsey said he can go down to the wharf, inspect cranes, vessels and securements, and supervise loading and unloading — but he can’t inspect computer code or cyber security.

New Times, New Risks

In all fairness, insurance language has changed since the 17th century, especially as technology races ahead in the 21st.

“If you read any hull form, it’s practically Shakespearean,” said Stephen J. Harris, senior vice president of marine protection UK, Marsh. “The language is no longer fit for purpose. Our concern specifically to this topic is that the antiquated language talks about crew being on board. If they are not on board, do they still legally count as crew?”

Harris further questioned, “Under hull insurance, and provided that the ship owner has acted diligently, cover is extended to negligence of the master or crew. Does that still apply if the captain is not on board but sitting at a desk in an office?”

Andrew Kinsey, senior marine risk consultant, Allianz Global Corporate & Specialty

Several sources noted that a few international organizations, notably the Comite Maritime International and the International Maritime Organization, “have been very active in asking the legal profession around the world about their thoughts. The interpretations vary greatly. The legal complications of crewless vessels are actually more complicated than the technology.”

For example, if the operational, insurance and regulatory entities in two countries agree on the voyage of a crewless vessel across the ocean, a mishap or storm could drive the vessel into port or on shore of a third country that does not recognize those agreements.

“What worries insurers is legal uncertainty,” said Harris.

“If an operator did everything fine but a system went down, then most likely the designer would be responsible. But even if a designer explicitly accepted responsibility, what matters would be the flag state’s law in international waters and the local state’s law in territorial waters.


“We see the way ahead for this technology as local and short-sea operations. The law has to catch up with the technology, and it is showing no signs of doing so.”

Thomas M. Boudreau, head of specialty insurance, The Hartford, suggested that remote ferry operations could be the most appropriate use: “They travel fixed routes, all within one country’s waters.”

There could also be environmental and operational benefits from using battery power rather than conventional fuels.

“In terms of underwriting, the burden would shift to the manufacturer and designer of the operating systems,” Boudreau added.

It may just be, he suggested, that crewless ships are merely replacing old risks with new ones. Crews can deal with small repairs, fires or leaks at sea, but small conditions such as those can go unchecked and endanger the whole ship and cargo.

“The cyber risk is also concerning. The vessel may be safe from physical piracy, but what about hacking?” &

Gregory DL Morris is an independent business journalist based in New York with 25 years’ experience in industry, energy, finance and transportation. He can be reached at [email protected]