It’s called back-breaking work for a reason.

Farmers are no strangers to back pain. The National Institute of Health (NIH) reports that lower back disorders are among the most frequently diagnosed musculoskeletal problems suffered by farmers.

A common cause of back pain in farmers is whole body vibration (WBV.) Dr. Nathan Fethke, associate professional of occupational and environmental health at the University of Iowa College of Public Health, has conducted extensive research on WBV. Fethke spoke with Country Folks about what he’d like farmers to know about WBV.

“WBV is the shaking you feel when you sit in a vehicle or machine that is able to travel under its own power, such as a car, speed boat, train or tractor,” Fethke explained. “Many workers are exposed to WBV, including operators of agricultural machinery.”

He said it’s important to know that not all WBV is harmful. For example, WBV has been investigated as a treatment for health conditions like osteoporosis. Also, the sensitivity of human tissues to vibration depends on the vibration frequency. “When we assess exposure to WBV in the workplace, our standard methods consider the vibration amplitude – you’d expect driving a car down a newly-paved road to have a lower vibration amplitude than driving a tractor over rough terrain – and the frequency content of vibration,” he said. “We also have to consider the duration of the exposure. In addition, our methods consider ‘shocks,’ which are brief, high-amplitude events like driving a car over a pothole.”

There are a few health effects associated with occupational exposure to WBV, but Fethke restricted his comments to back pain. At least 75% of adults will experience one or more major episodes of low back pain at some point during their lives. There are many risk factors, both on and off the job. On the job, exposure to WBV increases the likelihood of reporting low back pain and other back problems.

Not-so-good vibrations (and how to minimize them)

Dr. Nathan Fethke has researched how using agricultural machinery may lead to back pain in farmers. Photo courtesy of Nathan Fethke

“The effects may not be instantaneous,” he noted. “People might begin to experience low back pain after work at night, or the next morning, or in two days’ time. It’s also the case that people can work with agricultural machinery for many years without experiencing back problems but start having trouble later in life. For young producers, I think it’s important to say that minimizing WBV exposures today and throughout their farming careers is likely to pay off in the long run.”

Preventing or minimizing risks from WBV exposure during farm work can be difficult. Ag producers don’t always get to choose their working hours. During harvest, for example, producers need to get the crop in when it’s ready and when the conditions are optimal – so suggesting taking regular breaks to walk around or stretch might come across to producers as tone-deaf, Fethke said. “Also, many farm operations are small, and so having another person able to step in and take over the machine is not always feasible. However, when you do get out of a machine after operating it for a while, give your body a chance to recover before doing other physical work, like lifting heavy things.”

Other suggestions Fethke made include making sure that the seat suspension, if available, is properly adjusted to the operator’s body weight. If the seat tends to “bottom out” when traveling over rougher terrain, that’s a sign that the seat suspension mechanism may have failed and needs maintenance or replacement. Be sure to consult the owner’s manual or contact the dealer or manufacturer when replacing seat components. For example, installing a damper that is too stiff might do a great job at smoothing out the shocks but it will likely increase the overall or average WBV exposure levels.

“There may be options for replacing a complete seat and seat suspension assembly, both from the manufacturer and from third party vendors,” Fethke said. “The general condition of the machine and its suspension system should be regularly maintained.” He added that tire pressure can influence WBV levels too. For example, over-inflated tires can increase WBV levels.

“And please, make sure you are using machinery that is appropriately powered for the task!” he said.

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by Enrico Villamaino