Ergonomic Risk Factors in the Lab

The health and safety of scientists is directly dependent on the lab manager’s knowledge, awareness, and respect for ergonomics in the workplace. If the lab manager doesn’t make ergonomics a priority and an inherent part of the laboratory, then the scientists who work within the lab won’t do so either.

Many are unaware of the most common drivers of work injuries in the lab because of inadequate ergonomics training. It’s critical to know what to look for to help keep scientists safe. For example, many ergonomics injuries begin with signs and symptoms such as tight, tense, and sore muscles to the neck and mid to lower back. Another common complaint is hand or thumb pain. These symptoms eventually lead to musculoskeletal disorders, such as strains, overexertion disorders, carpal tunnel syndrome, or elbow tendonitis. These are the most common types of injuries in the lab, yet many of these injuries can be prevented with proper ergonomics practices.

“Just like there are risk factors that can lead to a heart attack or stroke, there are risk factors that can cause body discomfort.”

In addition to the safety and well-being of lab staff, the financial cost from ergonomic injuries is substantial. The average repetitive motion injury can cost about $40,000 per claim with lost time away from work. Injuries like this, combined with time away from work, impact the lab’s overall productivity and the viability of research and development.

Five examples of ergonomic hazards in the laboratory workplace

In the laboratory, there are a variety of locations where scientists work, including directly on the lab bench or counter, within the biosafety hood or fume hood, and within a glove box, among others. Within these areas, there are four essential tasks that occur most often—computer entry, mixing solutions, pipetting, and microscopy.

These tasks and work environments pose risk factors that can trigger discomfort anywhere in the body, from head to toe. Just like there are risk factors that can lead to a heart attack or stroke, there are risk factors that can cause body discomfort. These are called ergonomic risk factors. Understanding these risks allows the scientist to be in a better position to prevent the onset of discomfort. Below, we explore each one in more detail and the common lab tasks associated with each risk factor as well as some simple strategies to mitigate them.

1. Repetitive motion

Repetitive motion is doing the same motion pattern over and over. There are many tasks in the lab that are highly repetitive, and may be repeated multiple times within one minute, over 60 minutes, over a full day, every day—thousands of times. Such repetition takes a toll.

Some common tasks include:

Repetitive pinch and grasp
Repetitive thumb or finger motions with pipette use
Shaking liquids
Removing, replacing, or rotating lids or caps
Pouring into vials and beakers

As an example, consider the use of a 96-well plate filled by a single channel pipette. One plate requires 96 repetitions with the pipette. If 10 plates are filled within 15 minutes, then 960 repetitions occur. Within an hour, this grows to 3,840 repetitions using the same motion patterns over and over with the same body part.

To reduce exposure to repetitive motion, evaluate the task to see if it can be paced differently. Instead of performing one straight hour of pipetting, stop and interrupt the task to rest, stretch, or perform an alternative task that doesn’t require the same motion patterns. Many scientists continue to hold the pipette even when they aren’t actively using it. Placing the pipette on a carrier within easy reach allows the hand to relax.

Another option is using a multi-channel pipette to help reduce the repetition, but it doesn’t eliminate it entirely. The only way to effectively reduce or eliminate high repetition tasks is by introducing automation.

2. Forceful exertion

Many tasks require exertional forces that require you to push hard with your hands, thumb, or fingers to perform a manual task. This risk factor is referred to as forceful exertion. This can include pushing the pipette tip onto the pipette or pushing the plunger with your thumb, especially to eject tips. Other exertional hand tasks are isolating to the thumb and index finger, such as pinching or pressing up or down to manually cap small tubes.

Other tasks often require whole body exertions such as lifting, pushing, pulling, and carrying. Often the back, arms, and legs are involved in these tasks. Examples include lifting large beakers, carboys, or heavy containers from the floor or counter height to a cart.

Tasks should not require maximum grip or pinch force throughout the day; rather 15 percent or less is recommended. According to JTECH Medical, the average grip strength for men is about 72 pounds and 44 pounds for women. If you have a grip strength of 40 pounds, then your ideal exertion throughout the day should only be about six pounds, and pinch force should be less than two pounds, especially when repeated.

It’s no secret that pipetting can be risky to your fingers, hands, wrists, and up to your neck. In an article from Biohit called Raising the Standards of Mechanical Pipetting, the researchers state, “If pipetting more than 1,000 samples per day with a mechanical pipettor, one creates a total force for the thumb enough to lift an elephant.” This is important to recognize and control to reduce the risk of fatigue and eventually an injury.

In the same way that repetition is managed or eliminated, force should be managed similarly.

The strategies of task rotation, task interruption, task breaks, use of electric pipettes with reduced forces to the thumb and fingers, and even automation helps to reduce forceful exertion. If possible, change hands to perform the task or look for hand tools that help to make the grip easier.

3. Posture awareness

One of the most important aspects of good ergonomics is being aware of your own posture. As a starting point, it is important to understand the difference between neutral and non-neutral posture. It is also important to recognize tasks that may cause you to develop awkward or static posture.

Neutral standing posture requires the head to be in line with the shoulders, shoulders over the hips, hips over the knees and feet, and arms close to the trunk.

Neutral seated posture is the same, except the hips align with the knees close to a right angle (or slightly higher) and feet are on the floor, arms close to the trunk, with wrists in line with the forearms.

It’s best to try to preserve neutral posture as often as possible, especially when performing a seated or standing task.

An important distinction to understand is that posture is based on vision and reach—where your eyes need to see what your hands are doing. In other words, your body follows your eyes. Your eyes often follow your hands. It can also be based on the visual target. What do you need to look at? These are the things that predict your posture.

Awkward postures are those performed outside of 10-15 degrees of neutral alignment.

Some examples of awkward postures to the neck, arms, and wrists include:

Rounded or slouched posture
Downward neck flexion with microscope use
Wrist extension or deviations with pipette use or at a keyboard and mouse
Extended reaching in front, side, or overhead

Static postures are positions sustained for a period of time where you don’t move much. The time can vary based on the task or your tolerance for the posture. Static postures create muscle fatigue and can eventually cause a cumulative impact leading to discomfort. These postures are very common with biosafety hood tasks and microscope use.

Additional examples include:

Staying seated or standing too long
Sustained pinch or grip; holding a beaker or test tube with the non-dominant hand
Holding the pipette for an extended period
Using a microscope with the head and neck pushed forward or looking downward
Keeping your arms away from your body

The design of the work environment is often responsible for awkward postures, such as a work surface being too low or too high causing employees to sit forward or unsupported in their chair. Other typical awkward postures noted in the lab include looking down frequently, awkwardly holding the pipette, monitors being too low, and keyboards or mice placed too high.

To mitigate postural concerns, look around the lab and observe employee’s postures compared to the working height of the tools and equipment being used. Often, it is simply awareness of one’s posture that is the solution and knowing how to use equipment properly, as well as how to set it up to ensure neutral posture.

4. Contact stress

Contact stress is problematic because it results in reduced local blood flow to the area that is experiencing the contact. This can affect your muscles and nerves by causing pain and numbness due to compressive forces.

Examples include:

Standing on a hard floor
Leaning forearms and wrists on the hard edge of the lab bench when using a microscope
Sitting on the edge of a hard surface or seat
Leaning wrists on the desk surface when typing or mousing

To manage or reduce contact stress, be mindful of leaning on hard surfaces. Use armrests to reduce contact on the hard desk and keep items within close reach. Ensure seats offer significant seated cushion support where appropriate.

5. Organizational risk

Without an ergonomics process in place, your organization is vulnerable to ergonomic hazards and higher injury exposure. Ultimately, the lab manager sets the priority of ergonomics in the laboratory. If the lab manager emphasizes its importance, so will the scientists. Being mindful of laboratory ergonomics by recognizing and respecting the presence of ergonomic risk factors in the lab is critical. The most important action lab managers can take to protect their scientists is to encourage participation in laboratory ergonomics training to learn about ergonomic risk factors and how to mitigate them.

Knowledge followed by action is critical to mitigate ergonomic risk factors. It is not obvious or common sense to know how to work without risk of experiencing a musculoskeletal injury. Listen to your employees, watch how they work, look for the ergonomic risk factors, and then respond. Encourage self-correction and self-care when possible.

Additional actions lab managers can take are to use the services of a certified professional ergonomist who understands the tasks and routines inherently performed by lab scientists and who can evaluate for the presence of ergonomic risk factors, then develop practical solutions.

Make sure your organization’s executive leadership is engaged and committed to your ergonomics process by designating the resources necessary to include:

Ergonomic worksite analysis (office and lab)
Hazard prevention and control measures
Training and education

Together, you, your scientists, and your organization will be better off for using the science of ergonomics to recognize and improve employee work practices and the work environment for a healthier, more productive workplace.