Ergonomics in the Laboratory

Ergonomics is the science of fitting the workstation and tools to fit the user in order to reduce musculoskeletal stresses leading to injury and illness.  Whether you will be working in a research lab for one semester or throughout your career, there are ways to protect yourself from ergonomic hazards common in laboratory settings. 

Laboratory researchers are at risk for developing cumulative trauma injuries because of the repetitive nature of pipetting, use of small hand held tools, opening and closing vial caps, prolonged awkward postures at a microscope, and a variety of other laboratory tasks.

Repetitive motion injuries develop over time and occur when muscles and joints are stressed, tendons are inflamed, nerves are pinched and the flow of blood is restricted. Standing and working in awkward positions in laboratory hoods/biological safety cabinets can also present ergonomic problems. By becoming familiar with how to control laboratory ergonomic risk factors, you can improve employee comfort, productivity, and job satisfaction while lowering chances for occupational injuries.

Common ergonomic risk factors include:

• Repetition—performing the same motion over and over again.
• Awkward Body Postures—sustained holding of a bent position of the neck, back, hands/wrists, arms raised above shoulder level or arms extended out in front of the body.
• Force—physical exertion or pressure applied to any part of the body while working, such as lifting, pushing, pulling, gripping or pinching equipment or tools.
• Contact Stress—pressure on soft tissues of the body, such as the soft part of the palm, wrist or the sides of fingers by tools and sharp edges.
• Extreme Temperatures—cold air temperatures (55°F and lower) may cause loss of dexterity proportional to exposure time.
• Individual Susceptibility - Individuals may be predisposed to MDS based on their heredity, prior injuries, other illnesses, medication, smoking, etc.

Common symptoms of an ergonomic injury include:

• Pain
• Numbness and tingling
• Stiffness or cramping
• Shooting or stabbing pains
• Burning Sensation
• Inability to hold objects or loss of grip strength

Symptoms that go away overnight are usually a sign of fatigue. Symptoms that are continuous and don’t go away overnight may indicate a serious problem. Those experiencing such symptoms should notify the supervisor and seek medical attention. Ignoring symptoms can lead to chronic or serious injury.

Pipetting

Pipetting is one of the most common tasks performed in the research laboratory. It involves several ergonomic stressors - thumb force, repetitive motions, and awkward postures, especially of the wrists, arms, neck, and shoulders.

Possible Cause/Pipetting Action	Symptoms	Injury
Tip insertion and using wrist movements to manipulate pipette	Pain and inflammation in the wrist and elbow	Tendonitis- inflammation of the tendon
Gripping the pipette tightly and performing repetitive and forceful plunger and tip ejection activities with the thumb	DeQuervain’s – pain on the thumb side of the wrist; thumb may be tender to touch and a small knot may be felt. Trigger Finger – pain where the finger and thumb joins the palm; swelling; finger or thumb lock in position while being extended	Tenosynovitis – inflammation of the sheath that surrounds a tendon.     Specific Forms: ·    DeQuervain’s ·    Trigger Finger ·    Pipettor’s Thumb
Flexing, extending, and rotating the wrist while pipetting, and inserting and ejecting	Weakness in the hand; numbness or tingling in the; thumb and index and middle fingers; numbness or tingling of the palm of the hand; wrist pain; reduced finger and thumb movement, sharp, radiating, pain from hand to elbow or neck	Carpel Tunnel Syndrome – Compression of the median nerve and vessels running through the carpel tunnel in the wrist
Tip insertion and extension of the pipette away from the body	Elbow pain that gradually worsens; pain radiates to the forearm and back of the hand when grasping or twisting; weakened grip; pain when tendon is gently pressed near where it attaches to the upper arm	Epicondylitis (Tennis Elbow) – Inflammation of the muscles of the forearm, or their tendons near their origin on the bone of the upper arm
Resting the elbow on a hard lab bench while pipetting	Numbness or tingling in ring and little finger; loss of finger and hand strength; inability to straighten fingers; sharp sudden pain when elbow is touched	Cubital Tunnel Syndrome – Compression of the ulnar nerve in the cubital tunnel in the elbow

*”Pipetting, Ergonomics, and You”, Rainin a Mettler Toledo Company

The following are recommendations to prevent ergonomic hazards associated with the use of pipettes:

• Rotate pipetting tasks among several people or between laboratory tasks.
• Limit continuous pipetting periods to 20 minutes or less.  Take micro-breaks of 2 minutes for every 20 minutes of pipetting. Mild hand, arm and shoulder exercises and stretches are beneficial.
• Take short micro pauses of a few seconds, when you can't take a longer break.
• Use pipettes with newer trigger mechanisms requiring less force to activate, and use the pointer finger to aspirate, and the thumb to dispense.
• Use pipettes that fit comfortably in the user’s hand.
• Use thin-wall pipette tips that fit correctly and are easy to eject.
• Don’t press harder than necessary on the plunger.
• Use a variety of grips and alternate hands.
• Use minimal force when applying pipette tips.
• For tasks such as mixing or aliquotting, use an electronic pipetter with mixing functions.
• Use a multichannel pipetter for large aliquotting tasks.
• Avoid awkward static postures.  Work with arms in a neutral position close to the body to reduce strain on shoulders. Avoid working with arms in an elevated position.
• Avoid resting elbows and forearms on hard surfaces.
• Use shorter pipettes. This decreases hand elevation and consequent awkward postures.
• Use low profile waste receptacles for used tips. They should be no higher than the top of the tubes being filled.
• Clean pipetters on a regularly scheduled basis - this reduces "sticking" and improves quality of work.
• Adjust the height of the chair and work surface to minimize bending of neck and torso. 
• Alternate sitting and standing. If is necessary to stand for long periods of time during pipetting, provide anti-fatigue matting.
• Keep samples and instruments within easy reach.

Ergonomic Pipette Recommendations

Research has been conducted on the various types of pipettes to identify those pipettes that will reduce the ergonomics stresses that are placed on a person pipetting.  Current studies indicate that the Ovation BioNatural pipette significantly reduces thumb force, total finger force, wrist deviation, shoulder elevation, and wrist flexion/extension during aspiration.  To view the Ovation BioNatural pipette visit www.vistalab.com.  Rainin Pipetting Solutions also has developed the Pipet-Lite SL pipette which also reduces ergonomic stresses during pipetting.  To view the Pipet-Lite SL visit www.rainin.com.  For additional information regarding ergonomic pipettes, contact EHS at 274-2005.

Microscopy

When designing the microscope workstation, one should take into account the dimensions of its potential users. Since laboratory personnel come in many different shapes and sizes, the workstation should be made as adjustable as possible. Ideally, the microscopist should be able to adjust the height of his or her chair, work surface, and microscope. The following are recommended for control of ergonomic hazards associated with the use of microscopes:

• Use an ergonomically designed chair that provides adequate back support, adjustable height, and adjustable seat angle.
• Avoid jutting your chin forward or bending your neck down when using the microscope. Adjust the height of your microscope, workbench or chair as needed to avoid bending or tilting your neck.
• If your microscope is too low causing you to bend your head downward to look into the viewing tube, elevate the tabletop if possible. If your work surface is not adjustable, try placing books or binders under the microscope to elevate it. Raise your microscope to position yourself so that you are in as upright a posture as possible to reduce tilting your head and rounding your shoulders.
• If your microscope is too high causing you to raise your head when using it, elevate your chair and use a chair ring or footrest for leg support.
• Provide sit-stand seats for areas where there is restricted leg room. Try pulling the microscope toward the edge of the work surface to position the operator in a more upright posture.
• Remove false fronts and supplies from under the bench work area.
• If possible, use a cut-out work table. This puts the user close to the scope and gives an area for supporting forearms.
• If possible, try elevating the microscope or placing it at an angle so you can look directly into the eyepiece. This can help position the operator in a more upright posture and reduce rounding of the shoulders and neck.
• Use adjustable eye pieces or mount your microscope on a 30° angle stand for easier viewing.
• Avoid leaning on hard edges or use a pad to cushion the edges.
• Provide sloping arm rests to support the operator’s forearms while using adjustment knobs.
• Keep elbows close by your sides.
• Work with wrists in straight, neutral positions.
• Keep scopes repaired and clean.
• Use adjustable eye-pieces or mount your microscope on an easier viewing.
• Use television systems where possible to eliminate the use of binocular eye pieces.
• Use arm supports to provide support for your forearms while using adjustment knobs. A variety of supports are available from the following vendors:
• Ergo Source www.ergosource.com
• AliMed www.alimed.com
• Air Technologies www.airtech.net
• Spread microscope work throughout the day and between several people, if possible.
• Take breaks. Every 15 minutes, close your eyes or focus on something in the distance. Every 30-60 minutes, get up to stretch and move.
• Don’t use a microscope for more than 5 hours per day. Spread the use out over the entire work day, avoiding long uninterrupted periods of microscope work.

Microtome

Manual rotary microtome use in histology laboratories requires performing many repetitive functions. In the course of one day, a laboratory technologist may use between 40 and 50 cassettes or blocks a day, hence turning the microtome wheel for at least a 1000 time. This is not only repetitive work, but turning microtome's wheel also requires force or forceful exertion. Other repetitive microtome-related functions such as replacement of specimens and use of trimming wheel increase the probability of acquiring MSD.

• Purchase an automatic microtome to replace manual unit.
• Reduce force when operating hand wheel.
• Adjust the feed wheel position to reduce stress.
• Use motorized cutting.
• Use an external control unit like a front pedal instead of the hand-operated wheel.
• Apply padding to the work surface and the edge of the work surface to eliminate sharp edges and increase the amount of blood flow to the hands.
• Rotate tasks and take frequent short breaks.
• Use a fully adjustable ergo-task chair or stool with built-in solid footrest.

Cryostat Work

The following are recommended for control of ergonomic hazards associated with the use of a cryostat:

• Purchase an automatic foot operated cryostat.
• Avoid placing utensils such as forceps inside of the cryostat. Forceps should be placed outside of cryostat when not being used. This will keep the utensils at room temperature and reduce cold exposure to the hands and fingers.
• Use a fully adjustable ergo-task chair or stool with built-in footrest.
• Apply padding to the edge of the cryostat to reduce contact stresses.
• Take short stretch breaks.

Micro-Manipulation & Fine Motor Skills
Many laboratory procedures require repetitive use of the extensor and flexor muscles of the fingers and wrist. For example, removing caps and screw-off lids from vials, reaching into bins, use of forceps, etc. all require the use of these small muscle groups or result in awkward postures.

The following are recommended for control of ergonomic hazards associated with micro-manipulation techniques:

• If feasible for your work, use plastic vials with fewer threads. This will reduce twisting motions during capping and uncapping lids.
• Use small pieces of foam similar to the type used on pencils and pens, to prevent soreness on the fingertips, where fingers and forceps articulate. This will distribute the force over a greater surface area, thus reducing the compressive forces on the soft tissue.
• Practice using the forceps between the 1st and 2nd digits instead of using the thumb and 1st digit. Then try alternating between the two positions to reduce the use of the thumb. The thumb is used repetitively with almost every job task performed in the laboratory.
• Tilt storage bins toward the worker to reduce wrist flexion while reaching for supplies.
• Encourage mini-breaks and hand exercises.

Biosafety Cabinets and Laboratory Workbenches
Working in biological safety cabinets or fume hoods requires laboratory personnel to assume a variety of awkward postures due to limited work access, which restrict arm movement, and therefore significantly increase the amount of stress on joints of the upper limbs, neck, and back.

The following are recommended for control of ergonomic hazards associated with the use of biosafety cabinets and laboratory workbenches:

• Use an ergonomically designed chair that provides adequate back support, adjustable seat angle, and height adjustability between 28 inches to 33 inches.
• Use an ergonomically designed footrest for individuals whose feet do not rest comfortably on the floor or if you will be working for long periods in a biosafety cabinet.
• Apply closed-cell foam padding to the front edge of the biosafety cabinet (away from the downdraft) or workbench. This reduces contact forces by increasing the surface area that comes into contact with the forearm and therefore reduces the chances of impinging nerves, tendons, or blood vessels. If applying closed-cell padding to front edge of biosafety cabinet, make sure the material can be properly decontaminated.
• Remove drawers, supplies, refrigerators, etc. from under the workbenches and cabinet doors from under biosafety cabinets (provides leg room).
• Reduce eyestrain and awkward posture by keeping viewing window of hood/biosafety cabinet clean, and line of sight unobstructed.
• Raise cabinet couple inches upward to create a more conformable leg and thigh clearance.
• Position materials in laboratory hoods/biosafety cabinets as close as possible to avoid extended reaching. Perform work at least 6" back into the laboratory hood for safety reasons.
• Use a turntable to store equipment near the worker. This reduces excessive reaching and twisting, which places an increased load on the low back.
• Make sure that lights in hoods/biosafety cabinets are working properly.
• Use proper sitting posture and positioning.
• Take frequent micro-breaks to relieve forearm and wrist pressure caused by leaning on front edge of hoods/biosafety cabinets and perform stretching exercises.
• Use anti-fatigue matting for laboratory personnel who must stand for extended periods of time.

New biosafety cabinets may be purchased that incorporate the features below.   Desirable features for the new biosafety cabinets include:

• A perforated front grill reduced by 1 inch to 2 inches to bring the work platform closer to the laboratory worker.
• Adjustable height (hand-crank or hydraulic lift).
• Non-glare glass on the sash window and/or adjustable plexiglass barriers.

·         A platform configuration with “wells” for placement of tall containers.