Why you should care about ergonomic pipetting in your lab!

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Why you should care about ergonomic pipetting in your lab!

Are you someone that needs to stretch and mobilize your wrist muscles after manually pipetting into a 96 or 384 well plate? During plate set-up you are totally focused on dispensing the right sample into the right well, and only after ejecting the last tip do you realize that your wrist and thumb are pretty strained. Or maybe you spent the last hour sitting at a laminar flow cabinet pipetting stacks of cell culture plates that had to be fed or passaged? Once all your plates were back in the incubator, you probably intuitively stretched your back to loosen the muscles that had tensed while you were working. Even if you are lucky enough to be pain free, you will have noticed your colleagues complaining about it.

This empirical evidence that repetitive pipetting or an awkward posture can cause pain is supported by studies that report a significant increase in the risk of developing musculoskeletal problems when pipetting for more than 300 hours a year.1 Assuming you work between 180 and 200 days a year, pipetting for one or two hours a day results in an increased risk of injury. This data is 25 years old, so what’s changed? Evolution hasn’t changed our bodies during this time, but lab technicians’ workloads and sample throughputs have definitely increased. Automation is certainly more widespread than before but, nevertheless, pipetting for more than two hours is still common. And in today’s lab, when you are not pipetting you are sitting in front of a computer. Congratulations, you have full-time exposure to ergonomic hazards during your working day!

RSI – WRULD – MSD – CTD … I am confused?!?

There are many different terms and abbreviations that buzz around the subject of ergonomics (see glossary). To cut a long story short, they all essentially refer to pain in the hands, neck and shoulders caused by prolonged and repetitive movements. RSIs, for instance, cover a range of health problems brought on by frequent, highly repetitive actions, while WRULDs are conditions of the upper body caused by activities performed during the working day. Typical examples of conditions caused by repeated exposure to ergonomic hazards include carpal tunnel syndrome, tendonitis, tenosynovitis, and tennis elbow.

Glossary  
RSI Repetitive strain injury
WRULD Work-related upper limb disorder
MSD Musculoskeletal disorder
CTD Cumulative trauma disorder

What causes RSIs during pipetting?

The likelihood of developing an RSI is dependent on various risk factors; the greater the exposure to one or more risk factors, the higher the risk. This is especially true during prolonged manual pipetting processes, where lab workers encounter all the major risk factors.

Posture

In many labs, pipetting is done sitting at the lab bench. Just like sitting in front of your computer, it is important to keep your back straight and your head and shoulders aligned whenever possible, at the same time keeping your shoulders relaxed. Your legs should be placed beneath the lab bench with your feet flat on the floor or, if necessary, a footrest. Ideally, your arms should be kept close to your body; organize your workplace so that all your reagents and labware are in close proximity to avoid stretching.

The unfortunate reality is that awkward body postures can be seen daily in many labs, with some lab workers standing while pipetting, holding their tubes and pipettes at eye level, or sitting crouched in front of a laminar flow cabinet for hours at a time. Furthermore, lab tools, such as pipettes, have to be lifted up to be operated. The weight of the pipette affects how you hold it, and its size and the positioning of components – including the plunger, and tip ejection and volume change mechanisms – determines whether or not it can be held ergonomically.

Force

With manual pipetting, the plunger is thumb operated, allowing liquids to be aspirated and dispensed in a controlled way, with additional force needed to ensure all the liquid is dispensed. The thumb force is further increased when pipetting high viscosity liquids. Force is also needed to lift up a pipette and to hold it in an upright position during use, stabilizing the hand grip with the help of the thumb muscles.2 The weight of the pipette contributes to these forces.

Repetition

We all know that accurate and precise pipetting can be a challenge, involving numerous highly monotonous movements: attach the tip(s) to the pipette; depress the plunger with the thumb; move to the source liquid; raise thumb to aspirate; move to the target; depress the plunger with the thumb to dispense; and, finally, eject the tip. These movements are repeated over and over again – several hours a day, and several days a week.

RSIs impact your health!

Many lab workers are passionate about both their profession and the tools they work with. But is a working environment that affects your health and, as a consequence, your leisure time, really worth it? Probably not, when all it takes is small changes in your lab processes to avoid any ergonomic hazards.

Even if you are lucky enough to be pain free at the moment, adapting your working environment early on can avoid problems later. Start now! Talk to your employer. In many countries, employers are legally obliged to evaluate the RSI risk of each workspace by undertaking a Risk Assessment Test.3 The main goal of all employers is to have healthy staff who are in the lab, not with the doctor or physiotherapist. So be confident – the ergonomic improvements in your lab workflow will be appreciated by your colleagues and your employer!

Listen to your body!

The initial symptoms of an RSI include pain, aching or tenderness, stiffness, throbbing, tingling, numbness, weakness, and cramping of the hand, shoulder, neck, wrist or thumb. If you notice any of these early symptoms, first try to identify the repetitive motion causing the pain. If possible, avoid this motion in the future, or adapt your process.

If the pain persists even without performing the repetitive motion, visit a doctor, as treatment will be necessary. RSIs can be treated in various ways depending on the symptoms, from pain killers and steroid injections to physiotherapy. In severe cases, it may be necessary to take sick leave until the pain subsides.

How long it takes to recover from an RSI varies from case to case. But RSIs develop over a long period and, unfortunately, it can take a long time to get rid of them. Sadly, once you have been severely affected by an RSI, the risk of a reoccurrence is high. If the problem is ignored, it may result in long-term disability.

The graphic below shows some of the preventive measures that you can apply in your lab processes to avoid any RSI pipetting issues.

Graphic of a hand, orange spot on thumb to indicate hand pain from pipetting

Thumb

Problem

Manual pipettes require force to depress a plunger, which can cause problems such as thumb tenosynovitis. Manual tip ejection can lead to the same condition when the ejection force is too high.

What can you do?

Select a manual pipette with minimal plunger force and stroke distance. Electronic pipettes are ideal because the plunger is controlled by a microprocessor, requiring minimal thumb movement. Use tips that need the lowest possible ejection force for removal.

INTEGRA solutions

Graphic of a hand, orange spot on palm to indicate hand pain from pipetting

Hand

Problem

Hammering on tips can lead to long-term hand pain. In addition, holding the pipette too tightly for extended periods can lead to nerve damage and, potentially, carpal tunnel syndrome.

What can you do?

Don’t hold the pipette too tight. Choose a pipette with a finger hook to rest your hand, and low tip loading forces to reduce the need to hammer on tips.

INTEGRA solutions

  • EVOLVE manual pipettes are lightweight with low plunger force.
  • VIAFLO/VOYAGER electronic pipettes, and EVOLVE manual pipettes, use GripTips, which snap effortlessly onto the tip with no hammering on required.
  • The ASSIST PLUS pipetting robot features automatic tip loading and takes the pipette out of the hands of the user.
  • The VIAFLO 96/384 electronic pipette significantly reduces the time spent pipetting by dispensing/mixing an entire plate at a time, as well as offering electronic tip loading.
Graphic of an arm, orange spot on wrist to indicate pain from pipetting

Wrist

Problem

Twisting and turning the wrist too much and too often can lead to muscle injuries. Bending the wrist is especially problematic, as it places it in an unnatural position.

What can you do?

Choose a pipette that allows easy volume changes and keeps the wrist in a neutral position. Pipette handles that can be rotated help with this, allowing the user to choose the most comfortable position for them.

INTEGRA solutions

  • EVOLVE manual pipettes use three separate dials for straightforward volume changes, avoiding the typical approach of twisting the plunger. This allows quick volume changes that don’t affect the wrist.
  • VIAFLO/VOYAGER electronic pipettes have handles that can be turned to allow each user to find the most comfortable position for them. Volume changes are very easily done using a comfortable thumbwheel.
  • The ASSIST pipetting robots automate handheld electronic pipettes, removing the need to move the wrist. All volume changes and liquid handling tasks are carried out via a simple-to-use program.
  • The VIAFLO 96/384 electronic pipette can be operated in automatic mode, reducing the required hands-on time and wrist movements.
Graphic of an upper body, orange spot on neck and shoulder to indicate pain from pipetting

Neck and shoulders

Problem

Pipetting over long periods of time results in the neck and shoulders being hunched forward. In general, bad posture when pipetting can cause strains and restrict blood flow to the muscles. Awkward posture is commonly associated with working in a laminar flow air cabinet.

What can you do?

Be aware of your posture. The head should be directly above the shoulders, and the shoulders in line with the hips. Sit in the middle of your chair/stool with your back straight.

INTEGRA solutions

  • The ASSIST pipetting robots completely solve posture issues by removing the need for manual pipetting.
  • The VIAFLO 96/384 electronic pipette allows you to keep your neck in an upright position and your shoulders relaxed during the pipetting process. The motor assistance for moving the pipetting head enables an effortless workflow, while the electronic tip positioning guarantees optimal targeting of the wells without visual control.
graphic of an elbow with orange spot to indicate pain from pipetting

Elbow

Problem

Tennis elbow – lateral epicondylitis – can occur when pipetting over long periods, especially when the elbow needs to be fully extended. Resting the elbow on a hard surface while pipetting can compound the problem.

What can you do?

Don’t fully extend the elbow and keep labware as close to the pipetting area as possible.

INTEGRA solutions

  • The ASSIST pipetting robots eliminate elbow problems by automating handheld electronic pipettes, removing the need for manual pipetting.
  • The VIAFLO 96/384 electronic pipette is designed in such a way that the elbow is never fully extended, and can be automated to aid in pipetting processes.

References

  1. Björkstein MG et al. 1994. Hand and shoulder ailments among laboratory technicians using modern plunger-operated pipettes. Appl Ergon 25(2), 88-94.
  2. Wu JZ et al. 2014. Analysis of the musculoskeletal loading of the thumb during pipetting – A pilot study. J Biomech 47(2), 392–399.
  3. https://osha.europa.eu/en/tools-and-publications/publications/factsheets/80