I n 2009, Perry Galloway lay face-up on the concrete floor of his farm office, barking orders and conducting business, desperate for relief from back pain that was akin to sand paper on raw nerves. He knew the inescapable reality—no matter the agony, the farm show must go on.
Back pain is toe-tagged to agriculture work. Pushing, pulling and lifting are often the first culprits to place blame, but silently hiding behind these usual suspects might be the chief instigator: vibration.
A recently released study from the University of Iowa examines levels of whole-body vibration (WBV) absorbed during the operation of agriculture vehicles. The innovative analysis is highly suggestive that over the course of lifetime exposure, WBV could be physically devastating for particular growers.
Between 2011 and 2016, Nathan Fethke and a team of researchers attached sensors to more than 100 agriculture machines and vehicles in the Midwest: ATVs, combines, forklifts, skid loaders and tractors. The data was collected on 50 operations predominantly in Iowa but also in all neighboring states.
Fethke, a biomedical engineer and associate professor in the department of occupational and environmental health at the University of Iowa, College of Public Health, placed two accelerometer sensors in each farm vehicle to detect vibration levels. A specialized rubber disc was placed on top of each seat to measure up-down, forward-back and side-to-side movement. The second sensor was attached to the floor to record up-down movement. The results were ominously clear and pointed toward the deleterious effect of long-term WBV exposure. Using the European Union’s WBV exposure limit standards as a guide, Fethke’s data showed almost 60% of machines delivered a full day’s dose of WBV in less than two hours. According to Fethke’s research, farm operators drink directly from the WBV firehouse.
The longer an operator is in a vehicle, the greater the dose of WBV, a significant factor at planting or harvest, when farmers can often spend 10 to 15 hours per day driving machinery for weeks or months.
“The effects of whole-body vibration shouldn’t be underestimated,” Fethke urges. “Think about holding the top of a Slinky with your hand. When you move the Slinky up and down at the right frequency, the slightest motion at the top creates huge movements at the bottom of the spring. Basically, the incoming motion is smaller than the outgoing motion. The spine and back can respond to vibration in the same manner,” he adds.
The study showed WBV varies according to vehicle type. ATVs transmitted the highest levels of WBV, followed by heavy utility vehicles, tractors, pickups and semi-trailers. Combines (cotton pickers were not included in the study) afforded the most protection from WBV, likely due to vehicle mass and improved seat suspension systems, Fethke says.
On a sand ridge between the Cache and White rivers, Galloway, 51, grows corn, grain sorghum, rice, soybeans and wheat on 8,000 acres in Gregory, Ark., roughly 80 miles northeast of Little Rock. His operation also includes Hefty Seed Company and Broadview Aviation.
From the age of 8, Galloway has operated ag machinery. His formative years were a blur of farm work, football and the bulletproof antics of youth. Following college graduation, he returned full time to farming. By 1998, Galloway’s lower back was in open rebellion, and he bounced from one flare-up to the next.
In 2004, Galloway returned from a crop dusting run and executed a typical landing on a grass strip, but the vibration hammered his lower back.
“It was another step toward surgery,” he says. “It didn’t matter how careful I was; year over year my back was getting progressively worse.”
In 2008, Galloway went under the knife related to a bulging disc at the L5-S1 level, followed by a return to the rigors of farm work; a year later he was back in surgery. A second back operation was performed in 2009, again followed by a return to farm work, and just like before—two years later Galloway was on the operating table for a third surgery.
Galloway is not a farming exception, according to Fethke’s research. The frequency of back injuries related to agriculture work is remarkably high. “Regardless of the setting, we find 30% of farmers with at least one episode of back pain that limited their work activity just during the past year,” Fethke details. “Over the course of a career, the figure approaches 90% of farmers.”
Compounding the issue, the myriad ways a farmer encounters back pain throughout his or her career are increased by the consistency of WBV and its long-term consequences.
David Wilder is a professor in the department of biomedical engineering at the University of Iowa, College of Engineering, and an internationally renowned authority on back issues and occupational health, particularly in relation to how WBV and the seated posture can affect the back.
“Sitting while operating a tractor or other farm equipment is not a simple task. It often demands many changes in the farmer’s posture. When a farmer is sitting slouched forward in a tractor, especially with no lumbar support, all the fibers in the back of his lower back’s discs are stretched out and then tugged repeatedly because of the up-and-down, side-to-side motion of the tractor. The fibers have characteristics like the metal in a paper clip. You can repeatedly stretch them, but when you stretch them too far, too many times, they reach a limit, and they fail.”
Wilder further illustrates the point: “Ever ride in a vehicle that hits 80 mph and begins to shake like crazy? You already know to slow down or the structure will be damaged. So what about a farmer’s body? Logically, the rougher-the-ride vibration in a poor-seated posture that people are exposed to long-term, the greater the likelihood of severe back trouble,” Wilder adds.
Fethke acknowledges back pain as inherent to farming, but he says the consequences of WBV can be minimized. “Don’t underestimate the value of good seating and suspension. Seats wear down and bottom out over time, especially with the abundance of old tractors. It might just be a simple adjustment with springs or a hydraulic damper. Take the time to clean and grease under the seat.
Paying attention to and maintaining the seat and its suspension should be part of your overall machine maintenance routine.”
As for Galloway, he offers advice for other farmers. “This is part of our lifestyle, and we all know that. You have to drive for long hours, pick up 100-lb. items and push objects far heavier every single day, but I’d tell guys, especially young farmers, to try hard to be wise. Be conscientious to prevent back trouble, and you can possibly forego the issues I have in middle age.”