Ergonomics Awareness

What are WMSDs?

Work-related musculoskeletal disorders, or WMSDs, are injuries to the soft tissues of the body: the muscles and tendons that connect muscles to bones; ligaments that connect bone to bone; nerves; arteries and veins; pretty much every part of your body that's not a bone or internal organ. Pain is the most common symptom of these injuries.

What parts of the body do WMSDs affect?

WMSDs affect the parts of your body that are prone to injury when demands on them go beyond what they can handle. Typically these injuries occur in the moving parts of the body like your neck, low back, shoulder, elbow, wrist, and knee. Activities that can cause these injuries are called risk factors.* There is a list of them at the end of this handout.

What are some of the symptoms of WMSDs?

WMSDs have many different symptoms, many of which you may have experienced at one time or another. These include:

  • Discomfort
  • Pain
  • Swelling
  • Changes in skin color
  • Stiffness, tight muscles, or loss of flexibility in a joint
  • Unusual sensations: numbness, tingling, burning, heaviness, "pins and needles," or "falling asleep" of the hands or feet
  • Shooting or stabbing pains in arms or legs
  • Weakness or clumsiness in hands; dropping things.

Having one or more of these symptoms doesn't necessarily mean you have an injury, though.

What are some of the consequences of a WMSD?

Often these injuries start out small, as a little muscle pull or a slightly irritated tendon. It can become aggravated, especially if you keep doing the activity that caused the injury in the first place. The good news is that early treatment is often very simple and successful. Therefore, it's important for your own health to report symptoms as early as you can.

When should I report symptoms?

Of course, it wouldn't make sense to report all the little aches and pains you experience. But how do you know when symptoms are serious enough to need attention? Report your symptoms if:

  • Pain lasts more than 2 to 3 days in a row, is severe or worstening
  • Pain spreads or "travels" down an arm or leg
  • You experience numbness or tingling
  • You suffer from weakness or loss of strength
  • Symptoms keep you from sleeping at night
  • Symptoms get worse while working

When in doubt, it's better to report symptoms and be told there's nothing wrong than to wait too long.

How should I report symptoms?

  • Discuss symptoms with your supervisor
  • Consult your health care provider
  • Fill out the UW Incident / Accident / Quality Improvement Report form that is available online for editing and printing.

See https://oars.ehs.washington.edu for information about accident reporting.

To Protect Against WMSDs

  1. Work-related musculoskeletal disorders (WMSDs) are injuries that accumulate over time. If typical work activities expose you to one or more risk factors* known to cause injury, use caution regarding how these activities are performed and look for ways to minimize exposure by reducing the:

    • Duration (length of time without pause for rest)
    • Frequency (how often)
    • Intensity (amount of force)

  2. Supervisors and employees should:

    • Identify, evaluate and reduce risk factors* to an acceptable level or to the degree feasible.
    • Put reductions in place and check back to make sure they are working.
    • Include specific training with implementation, if required.
    • See that ergonomic awareness education is available for anyone exposed to risk factors*. Videos and other information are available from EH&S.

Further Information is available at:
EH&S: http://www.ehs.washington.edu/ohsergo/index.shtm
L&I: http://www.lni.wa.gov/wisha/ergo/
UW Occupational Health and Safety Office: (206) 543-7388

Employee Involvement in Ergonomics

You the employee are an important part of any ergonomic safety program. You know your job better than anyone else, so if you or your supervisor identify risk factors*, you need to work together to try to reduce them.

If you are asked about your job or observed while you work, be sure to share any concerns or ideas for improvements you have. Your job may not need to be changed, but if it is, you may also receive training on how best to work with the changes. If for some reason the changes aren't working for you, be sure to let your supervisor or one of the contacts listed above know about it.

Ergonomic Risk Factors
Awkward Postures
Working with hand(s) above the head or elbow(s) above the shoulder(s) More than 4 hours total per day Or repeating that position more than once per minute, more than 4 hours total per day
Working with the neck bent more than 45° (without support or the ability to vary posture) More than 4 hours total per day
Working with the back bent forward (without support or the ability to vary posture) More than 30° for more than 4 hours per day Or more than 45° for more than 2 hours per day
Squatting More than 4 hours total per day
Kneeling More than 4 hours total per day
High Hand Force
Pinching an unsupported object(s) weighing 2 or more lbs. per hand Or pinching with a force of 4 or more lbs. per hand, combined with highly repetitive motions More than 3 hours total per day
Pinching an unsupported object(s) weighing 2 or more lbs. per hand Or pinching with a force of 4 or more lbs. per hand, combined with wrists bent in flexion 30° or more or in extension 45° or more More than 3 hours total per day
Pinching an unsupported object(s) weighing 2 or more lbs. per hand Or pinching with a force of 4 or more lbs. per hand More than 4 hours total per day
Gripping an unsupported object(s) weighing 10 or more lbs. per hand Or gripping with a force of 10 or more lbs. per hand, combined with highly repetitive motions More than 3 hours total per day
Gripping an unsupported object(s) weighing 10 or more lbs. per hand Or gripping with a force of 10 or more lbs. per hand, combined with wrists bent in flexion 30° or more or in extension 45° or more or in ulnar deviation 30° or more More than 3 hours total per day
Gripping an unsupported object(s) weighing 10 or more lbs. per hand Or gripping with a force of 10 or more lbs. per hand More than 4 hours total per day
Highly Repetitive Motion
Using the same motion with little or no variation every few seconds (excluding keying activities) More than 6 hours total per day
Using the same motion with little or no variation every few seconds (excluding keying activities) combined with wrists bent in flexion 30° or more or in extension 45° or more or in ulnar deviation 30° or more, and high, forceful exertions with the hand(s) More than 2 hours total per day
Intensive keying More than 7 hours total per day
Intensive keying combined with awkward postures More than 4 hours total per day
Repeated Impact
Using the hand (heel/base of palm) as a hammer more than once per minute More than 2 hours total per day
Using the knee as a hammer more than once per minute More than 2 hours total per day
Lifting
Heavy lifting More than 55 lbs. more than 10 times per day Or more than 75 lbs. more than once per day
Frequent lifting More than twice per minute More than 2 hours total per day
Awkward lifting More than 25 lbs. above the shoulders, below the knees or at arms length More than 25 times per day
Hand-Arm Vibration
High vibration Powered hand tools such as impact wrenches, chipping hammers or chainsaws More than 30 minutes total per day
Moderate vibration Powered hand tools such as sanders or jig saws More than 2 hours total per day