Let's Get Physical

How to modify your tools to prevent pain at the bench.

Kelly Rae Chi
Jan 1, 2009

If you're like most researchers, as you plan experiments, chances are your to-do list takes precedence over your comfort. Bench work has a long history of causing physical woes, and as new technologies push the definition of "high-throughput," an increasing number of labs are becoming more like assembly lines. Even with better automation, ergonomics problems are on the rise in the lab, says David Rempel, a researcher in occupational medicine from the University of California, San Francisco.

That's because many labs are ill-equipped for the increase in efficiency. "The problem is, when someone sets up the lab environment, those decisions, rarely, if ever, involve ergonomics decisions," says Blake McGowan, senior consultant and ergonomics engineer at Humantech, a company in Ann Arbor, Mich. From heavy culture plates and liquid containers in large, automated labs to hours-long microscope work and the use of small forceps or other tools that increase pinch forces...

Squeeze extension

Task: Multiple runs of gel electrophoresis

Troubleshooter: Blake McGowan, senior consultant and ergonomics engineer at Humantech, Ann Arbor, Mich.

Problem: Researchers in a large medical diagnostic company were repeatedly squeezing 1-inch binder clips to clamp glass plates to an electrophoresis apparatus. They needed the tension for clamping the plates, but repeating the clamping motion as many as 100 times a day was creating discomfort.

Solution: McGowan went to the lab and measured the actual force it takes to grip the clamp, as well as the forces the clamp exerted onto the plates. He first tried several types of manufactured clamps, but the pinch forces proved to be just as high. So he designed extensions to the binder clips to give the researchers more leverage, thus reducing carpal tunnel syndrome symptoms.

The extension is 2-inch long by 1⁄2-inch wide piece of plastic that fits over the top of the metal binder clip and is fastened with a screw.

Costs: $40 to custom manufacture at a machine shop

Power grip

Task: Manipulating and characterizing fruit flies under a microscope

Troubleshooter: Mallory Lynch, certified professional ergonomist at the University of California, Berkeley

Problem: When examining anesthetized flies researchers had to continually shift the CO2 mat below the flies, resulting in an awkward position for their left hands. Using their right hands, they held small paintbrushes to move the flies on the mat, resulting in a small pinch grip.

The postures were difficult but necessary to sustain for several hours. The group sought Lynch's help in order to prevent injury from hand strain.

Solution: To prevent the researchers from having to open and extend their left fingers, Lynch tried a few different variations. First, she extended the left side of the CO2 mat by about three inches, using a piece of plastic fastened to the pad using Velcro. Then, Lynch tried several different grips that she attached to the extension: a wooden drawer knob, a 2-inch slice of a Styrofoam water noodle, or a plastic loop workers could fit their left thumbs through.

"The foam seemed to work pretty well, but if it was cut too small it was awkward," Lynch says, adding that people's favorites seemed to vary.

On the right hand, Lynch modified the grip on the paintbrush, changing it from a "pinch grip" to a "power grip"—much like how a person might grip a hammer. A piece of plastizote foam served as the new handle, and she glued it at a 45 degree angle to the handle of the paintbrush.

Costs: Materials can be purchased at a hardware store for under $20, and the plastic mat extension was custom cut for $4.

Wet lab toolkit

Task: Synthesizing natural compounds; tasks involve filtrations and pouring and lifting jars of liquid

Troubleshooter: Sherry Chavez, graduate student at the University of Utah, Salt Lake City

Problem: Chavez has rheumatoid arthritis, which affects her hands, elbows, and hips. She needed easy and inexpensive fixes for filtering and pouring solutions.

Solution: With some help from friends, Chavez designed several tools, including a stopcock adaptor, hood knob handles and a bottle handle, that help to reduce the strain on her wrists and fingers when she grips and turns objects.

The stopcock adaptor Chavez designed has a larger handle enabling better control of the flow of liquid when carrying out separations and funneling. The adaptor fits over the top of two different-sized stopcocks and is made of Teflon, which is resistant to dichloromethane, a solvent commonly used in her lab.

Chavez also had plastic covers made for the star-shaped faucet knobs found on the lab hood that control the water, nitrogen and air lines. "Turning the knobs put my wrist at a very strange angle and exerted a lot of pressure," she writes in an email. The plastic covers allow her to turn the knobs using her palms instead of her fingers.

To create a bottle handle for glass solvent jars, Chavez molded Thermoplastic pellets into a handle shape. Plastic-coated wires allow her to fasten the handle to whatever bottle she's using.

Costs: $15 for several stopcock adaptors and hood knob handles, and $3 for the bottle hugger, not including labor costs.

Automating plating

Task: Plating bacterial colonies in a highthroughput DNA sequencing production line

Troubleshooter: Marty Pollard, Instrumentation Group Leader at the US Department of Energy Joint Genome Institute (JGI) in Walnut Creek, Calif., and collaborators at JGI and Lawrence Berkeley National Laboratory in Berkeley, Calif.

Problem: Technicians were fatigued after holding and rotating five large culture plates at one time. The plates were heavy, about 8 lbs., and technicians had to rotate several batches for up to 40 minutes at a time while holding them underneath the fume hood. This created awkward hand and wrist postures and discomfort in the back and shoulders. "Our ergonomists came in and realized that it was a high-risk activity," Pollard says.

There was no off-the-shelf solution, and the researchers did not want to slow their work by limiting the number of assays per person per day.

Solution: They moved the technique to a spot outside the fume hood, and built a tabletop instrument. "[The research workers] came to us with a small drawing, and we built a sheet metal version of this with handles and it worked great," Pollard says. The tabletop fixture they built holds the stack of plates and allows operators to rotate them in unison with a ball joint. The device, called the Shake 'n Plate, is equipped with both knobs and handles to allow fine control.

The Shake 'n Plate won first place in the "team-driven workplace solutions" category at the Applied Ergonomics Conference in 2007. Pollard's instrumentation group has since developed a fully automated version that improves the consistency of plating from person to person.

Costs: The materials cost only about $50. But the total cost, $750, comes from one day's worth of labor in a machine shop. You can get one from California-based Zach Radding Designs; Radding also sells an automated version for roughly $3,000.


Tips for reducing your ergonomic load

Talk with your institution.
Many larger universities have staff ergonomists in their environmental health and safety departments that can help identify the problem point in your protocol and find a fix.

Train your employees.
Check with your university, such training might be partially funded. If there's no ergonomist on campus, consider talking to a company or consultant, but make sure the person helping you is a certified professional ergonomist, Humantech's McGowan says.

Manage your group's stress levels.
Cognitive stress has been shown to exacerbate physical aches, so lab heads should delegate tasks accordingly and acknowledge the contribution of their employees, says Kermit Davis, a researcher specializing in occupational ergonomics at the University of Cincinnati in Ohio. For example, you might not want to have all time-pressure tasks go to one person, he says. "Identify, as a manager, when increased levels of stress are coming and when there can there be interventions."

Prevent pipetting injuries.
The Centers for Disease Control and Prevention advises bench scientists to take micro-breaks of 3-5 minutes for every half hour of pipetting. If you're pipetting for long spans of time and more frequent breaks aren't feasible, consider an ergonomically designed pipette. "There are a lot of good pipetting solutions out there," says UCSF's David Rempel. Pipettes with a non-axial design, for example, keep the wrist in a neutral position. Companies such as Eppendorf and Rainin make ergonomic pipettes, which cost from $200 to $700. The Vision series of electronic pipettes, sold at Viaflo, won the LabAutomation 2008 New Product Award. The pipettes start at about $350, can handle a wide range of liquid volumes, and are the first to feature an iPod-like touch wheel controller for menu navigation.

Do something different.
"Put some kind of dynamic motion into your break," Davis says. For example, if you're seated at a microscope for hours at a time, take a short break to check your mailbox. "This doesn't have to be non-productive time," he adds. Your "break" could be as subtle as shifting your position to as drastic as changing your task.

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