Stop the strain

Researcher recommends a multidimensional approach to preventing overexertion injuries

  • According to the National Safety Council’s “Injury Facts” 2011 edition, overexertion is the third leading cause of injury in the United States. Insurance data indicates overexertion injuries cost employers $13.4 billion annually in direct costs.
  • Effective intervention requires a multidimensional approach that includes engineering, administrative and person-focused interventions; organization; and supervision.
  • Sociopsychological and rehabilitation elements should be considered in an ergonomics program.

By Deidre Bello, associate editor

Overexertion has long been among the leading causes of nonfatal workplace injuries, and attempts to combat it continue to be a burden on employers and their pocketbooks.
An estimated 3.5 million overexertion injuries occur every year, most of which are from excessive lifting, lowering, pushing, pulling or carrying. Back injuries are the most common form of overexertion in the workplace and can result in huge costs. According to a 2010 report from the Boston-based Liberty Mutual Research Institute for Safety, in 2008, overexertion cost businesses $13.4 billion in direct workers’ compensation costs – accounting for more than 25 percent of the overall $53.4 billion national burden.

Overexertion injuries continue to be a problem because prevention requires a multidimensional and systematic approach, according to Michael J. Smith, professor emeritus in the department of Industrial and Systems Engineering at the University of Wisconsin-Madison.

“Without a multidimensional approach, it’s pretty hit and miss as to whether you’re going to be effective,” Smith said.

The multidimensional approach

Overexertion results from sprains (stretching or tearing a ligament) and strains (stretching or tearing tendons or muscles). Although the number of these musculoskeletal disorder cases declined in 2009, overexertion continues to be an issue for many industries, including private-sector laborers; freight, stock and material movers; truck drivers; and nursing aides, orderlies and attendants. In 2010, overexertion was the third leading cause of injury in the United States, according to the National Safety Council.

In October 2001, Smith, Ben-Tzion Karsh of the University of Wisconsin-Madison and Francisco B.P. Moro of the University of New Brunswick-Saint John presented findings from a study of more than 600 works of scientific literature relevant to work-related MSDs. The researchers concluded that the most effective MSD interventions were those that used multiple components – engineering, administrative and person-focused.

Smith, who also is a former research program director at NIOSH, told Safety+Health magazine that a good multidimensional ergonomics program should include procedures for engineering design practice, training, organization and supervision.

During training and orientation, workers need to understand why overexertion contributes to the types of injuries that occur, Smith said. “One of the problems we have … is everybody engages in lifting and pulling and pushing and carrying from the time they start walking to the time they come to the workplace. Many people come to the workplace thinking they can do that properly,” he said. “We need to get people to understand that there are specific ways we can approach materials handling, and this is very critical.”

Training should include a hands-on learning approach with basic how-to lessons and interaction with the instructor, Smith said. “That means hands-on with an instructor watching them, giving them advice when they do it wrong and including supervision in these types of activities,” he said.

In cases where training falls short, research has shown engineering out hazard-through-design practices and controls can be effective in reducing the risk of injury. Employers can provide assistive devices for pulling, reaching, carrying and lifting, but need to acknowledge that engineering processes alone will not lead to success because they do not take into account personal factors, such as age, physical condition and body weight.

The safety professional’s role in overexertion injury prevention is to help all levels of an organization recognize which procedures are most effective at combating overexertion, Smith said, adding that success will depend on the organizational processes in place. A strong safety culture influences management to place safety ahead of simply getting the job done, he said.

Companies that are successful at preventing overexertion-related injuries also include an interactive supervisory process in their ergonomics safety program, Smith said. These organizations have supervisors who understand the issues and are comfortable approaching employees in a positive way to correct problems. Supervisors also can help the safety professional by sharing the need for a diverse workforce and providing input on measuring risks, applying safety standards and identifying whether additional training is necessary.

“Supervisors, through observation, can be a critical link in finding where there is a poor fit,” he said.

NIOSH advises supervisors and safety professionals to look for awkward postures, repetitive motions, forceful exertions, pressure points and static postures.

Sociopsychological and rehabilitation processes

Download ergonomic guidelines for manual materials handling from NIOSH

Incorporating a psychosocial process into an ergonomics safety program is necessary to understand how stress can affect safety, Smith said. Stress tends to cause people to modify work practices to accommodate their tasks and get the job done, he said.

According to the Centers for Disease Control and Prevention’s National Center for Health Statistics, the number of injuries and illnesses reported in any given year can be influenced by the level of economic activity, working conditions and work practices, worker experience and training, and number of hours worked.

If an organization is struggling with the economy and production, this may lead to problems for employees who may question job stability, said Kimberly Watson, safety director at Southwire Co., a manufacturer of wire and cable used in the distribution and transmission of electricity.

“Greater mental distraction is going to cause employees to not be as focused at work or at the job they are performing. Distraction puts an employee at risk for having a work-related injury. During these times, employers may need to provide additional reassurance for securing their employees,” Watson said. Organizations also should take the opportunity when production is down to re-examine their production flow and equipment design, and make changes to improve safety, she said. “If an employee sees an employer looking to re-enhance safety, then they look at it as a benefit, they look at is as a value.”

When it comes to preventing overexertion injuries, Carrollton, GA-based Southwire examines activities that put workers at risk. Through behavior-based safety training, employees learn to recognize unsafe acts and think critically about identifying risks in their work environment, Watson said.

Southwire employees also have a number of resources available to reinforce safety, including safety meetings, on-the-job coaching, job hazard analyses and an anonymous reporting system.

“We want it to be a coaching and mentoring type of culture,” Watson said. 

At Southwire, employees work through a rehabilitation process to ensure workers returning after an incident are able to rejoin the workforce. The company examines the job the worker performed before the incident and includes the worker’s physician’s input into appropriate modifications, Watson said.
According to Smith, the rehabilitation process is an area that needs more attention. He said some organizations stop short by leaving it up to doctors to determine the rehabilitation approach.

“Very smart companies actually get involved with medical care early on and integrate the person back into the company carefully and slowly to get them to build up to the capacity they were up to before an incident,” Smith said.

The National Safety Council advises safety and health professionals to re-evaluate an employee’s work capacity following an injury. An employer should consider whether or not some work restrictions should be applied. Rehabilitation also may be necessary, according to the council.

Measuring progress

NSC highlights overexertion prevention
Overexertion is one of the topics highlighted in June for National Safety Month 2011, sponsored by the National Safety Council.

Smith, Karsh and Moro’s 2001 study concluded that the problem organizations face when implementing multiple-component interventions for MSD injuries is the impact of a single component cannot easily be determined. The researchers advised using a process of measure and manipulation checks to better understand interventions, and said the checks should be based on injury and hazardous surveillance, job ergonomics analyses, and current scientific knowledge.

Progress in preventing injuries related to overexertion is measured at Southwire by looking at leading and lagging indicators, Watson said. While she admits it is not always beneficial to use post-incident measurements – such as workers’ comp claims, OSHA 300 logs, absenteeism rates and worker complaints – they do offer some preventive lessons.

“We learn from our incident investigation by utilizing root-cause analysis to put the necessary corrective action in place to prevent [incidents] from reoccurring,” Watson said. “By tracking and analyzing our recordable injuries and safety observations, it offers the opportunity to perform trending analysis at a specific piece of equipment, facility location and/or at a companywide level. Trending enables us to determine where our safety focus and efforts need to be placed. It may be simply a matter of coaching an employee who may not understand the risk.”

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