Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

ELEMENTS OF ERGONOMICS PROGRAMS

Step 1: Identify Risk Factors

Learn who is at risk for Work-related Musculoskeletal Disorders (WMSDs)

Incidents of possible WMSDs are either isolated to a particular job/task or widespread, affecting multiple departments. Records of complaints and injuries are often enough to reveal the scope of a WMSD problem.

Table 1.1: How to Look for Records of WMSDs

Where to Look What to Look For
Company OSHA Form 300 logs Workers’ compensation claims Specific cases, such as carpal tunnel syndrome or tendinitis. Nonspecific cases, such as hand/wrist pain or back pain
Records of worker complaints Complaints of undue stress, localized muscle fatigue, discomfort, pain that does not go away after rest
Records of workers visiting the clinic Mentions of physical aches and pains related to certain types of work assignments
Job task evaluations, job safety analyses and job hazard analyses Job tasks involving repetitive and forceful exertions, frequent/heavy/overhead lifts, awkward working positions, or use of vibrating equipment
Company policies and directives Evidence that job/task modifications (like increasing line speed) were proposed specifically to increase worker output and overall productivity
Trade publications Evidence of WMSDs in the field

OSHA logs and company medical records are readily available to most employers. These records can be used to calculate incidence rates (i.e. new cases) and prevalence rates (i.e. new and old cases) of MSD problems, which come in handy for step 3. Organizations that have identified possible WMSDs should contact NIOSH for a Health Hazard Evaluation (HHE). Please visit Health Hazard site to learn more about HHEs.

Click here to search for examples on HHE reports on Musculoskeletal Disorders. Possible key words to search for include ergonomic, or musculoskeletal disorders.

Learn about workplace conditions that put you at risk for WMSDs

Workplace conditions contribute to physical and psychological stress and can negatively affect the musculoskeletal system. Physical stress comes from the force, repetition and postures required in job tasks. Practical Demonstrations of Ergonomic Principles (2011) states that there are neutral postures, awkward postures, and static postures. When your muscles and joints are resting and relaxed you’re in the neutral posture. Awkward or unnatural postures require more and more exertion from your muscles, tendons, nerves and bones as movements reach the limits of the range of motion and can lead to MSDs. Also, if you maintain the same position, even in a neutral posture, for an extended period of time, this static posture can cause additional muscle fatigue and disrupt blood flow.

Psychosocial stress results from work organization factors (e.g. fatiguing workload, repetitiveness, lack of job control, and extremely high or low mental demand, low job satisfaction), factors outside the workplace (parental responsibilities), and individual worker factors ( e.g. genetic factors, educational status, culture, and personality traits). The table below provides a list of risk factor conditions that contribute to WMSDs. In a job task there can be more than one of these risk factors present (e.g. the Awkward Postures image includes contact stress, poor shoulder/wrist posture and excessive force while pushing).

Table 1.2: Examples of Risk Factor Conditions

one man dumping a huge boulder and another man retrieving it - awkward postures

Awkward Postures

man placing large sack overhead

Overhead Work

twist and carry

Twisting and Carrying Loads

women giving a haricut with scissors

Wrist Deviations

contact stress

Contact Stress

men caring a large panel of plywood

Poor Shoulder/Wrist Posture

man lifting bulky loads

Lifting Bulky Loads

Person Welding

Hand-Arm Vibration

man using a forklift to place a large load

Whole Body Vibration

Learn what jobs put you at risk for WMSDs

To identify specific jobs or job tasks that put workers at risk for WMSD problems, you need to lay the groundwork for early intervention and WMSD prevention. A single job setting may present more than one risk factor for WMSDs. Your level of risk for developing WMSDs depends on the intensity, frequency, and duration of your work tasks. The U.S. Bureau of Labor Statistics provides data on occupations with physical requirements. These requirements may become risk factors for MSDs if your work includes high intensity, frequency, or duration. The Occupational Requirement Survey grades work-related strenuousness at five levels: sedentary, light, medium, heavy, and very heavy. Table 1.3 summarizes the data from the U.S. Bureau of Labor Statistics’ Occupational Requirements Survey.

The NIOSH Worker Health Charts below are based on the National Health interview Survey (NHIS) data from the 2015 Occupational Health Supplement. Each figure contains an occupations’ estimated prevalence with a 95% lower and upper confidence limit.  All the figures are unadjusted prevalence rates, with no adjustment for age, sex, and race. The figures are as follows:

Figure 1.1 Unadjusted Prevalence of Frequent Lifting, Pushing, Pulling, or Bending by Occupation

An estimated 60,471,000 (out of 145,777,000) U.S. adults experience frequent lifting, pushing, pulling or bending job tasks, with an average prevalence of 41.48%.

Figure 1.2 Unadjusted Prevalence of Frequent Standing or Walking by Occupation

An estimated 97,314,000 (out of 145,818,000) U.S. adults experience frequent standing or walking, with an average prevalence of 66.74%.

Figure 1.3 Unadjusted Prevalence of Low Back Pain Attributed to Work by Occupation

An estimated 8,274,000 (out of 147,742,000) U.S. adults were affected by low back pain, with an average prevalence of 5.68%.

Figure 1.4 Unadjusted Prevalence of Current Carpal Tunnel Syndrome Attributed to Work by Occupation

An estimated 2,445,000 (out of 145,699,000) U.S. adults were affected by carpal tunnel syndrome, with an average prevalence of 1.68%.


Table 1.3: Common MSD Risk Factors Associated with Various Work Settings

Work Settings Potential Risk factors
Architecture & Engineering
  • Lifting or carrying (average max. 26lbs)
  • Poor/Awkward Posture (med. 6hrs sitting)
  • Strenuousness
    • Medium
Arts, design, entertainment, sports and media
  • Poor/Awkward Posture (4-5hrs. sitting)
Building and grounds cleaning and maintenance
  • Poor Shoulder/Wrist Posture (overhead reaching)
  • Lifting or carrying (average max. 42lbs)
Business and financial operations
  • Poor/Awkward Posture (average 6hrs sitting)
  • Poor Shoulder/Wrist Posture (overhead reaching)
  • Lifting or carrying (max. median 10lbs)
Community and social services
  • Poor Shoulder/Wrist Posture (overhead reaching)
  • Poor Posture (~5hrs. sitting)
Computer and mathematical
  • Poor/Awkward Posture (~7hrs. sitting)
  • Lifting or carrying (average max. 16lbs)
  • Contact stress (interaction with keyboard)
Construction and extraction
  • Lifting or carrying (average max. 66lbs)
  • Heavy Vibration
    • Hand-Arm Vibration
    • Whole Body Vibration
  • Strenuousness
    • Heavy
Education, training, and library
  • Lifting or carrying (average max. 27lbs)
  • Contact stress ( interaction with keyboard)
Food preparation and serving related
  • Strenuousness
    • Medium
Healthcare practitioners and technical
  • Poor Shoulder/Wrist Posture (overhead reaching)
  • Lifting or carrying (average max. 44lbs)
Healthcare support
  • Lifting or carrying (average max. 45lbs)
  • Strenuousness
    • Medium
Installation, maintenance, and repair
  • Poor Shoulder/Wrist Posture (overhead reaching)
  • Lifting or carrying (average max. 65lbs)
Legal
  • Poor/Awkward Posture (sitting)
  • Lifting or carrying (average max. 19lbs)
Life, physical, and social science
  • Poor/Awkward Posture (crouching)
Management
  • Strenuousness
    • Light work
Office and administrative support
  • Poor/Awkward Posture (~6hrs. sitting)
  • Strenuousness
    • Light Work
Personal care and service
  • Lifting or carrying (average max. 39lbs)
  • Strenuousness
    • Medium
Production
  • Lifting or carrying (average max. 45lbs)
  • Strenuousness
    • Medium
Protective service
  • Poor Shoulder/Wrist Posture (overhead reaching)
  • Lifting or carrying (average max. 74lbs)
Sales and related
  • Strenuousness
    • Medium
Transportation and material moving
  • Poor Shoulder/Wrist Posture (overhead reaching)
  • Lifting or carrying (average max. 52lbs)

Learn specific MSDs with their risk factors

NIOSH 1997 Publication Musculoskeletal Disorders and Workplace Factors: A Critical Review of Epidemiologic Evidence for Work-Related Musculoskeletal Disorders for the Neck, Upper Extremity, and Low Back reviewed specific MSDs in relationship to risk factors from literature reviews. During that time MSDs were reported in five separate body regions (neck, shoulders, hands/wrist, elbow, & low-back). The table below provides risk factors known at that time to be strong or some evidence contributing to those specific MSDs.

Table 1.4: The Type of MSDs’ Risk Factors

Type of Musculoskeletal Disorder Risk Factor(s)
Neck MSD
  • Repetitive work (repetition with awkward neck posture)
  • Forceful work (arms and hand movement generate force stress on the neck)
  • Static awkward posture (tension-neck syndrome)
Shoulder MSD (shoulder tendinitis)
  • Repetitive work (repetition with awkward shoulder posture)
  • Static shoulder load (contact stress)
  • Overhead work
Elbow MSD (Epicondylitis)
  • Forceful work (wrist generates force stress on elbow)
  • Combined Risk Factors
    • Force & repetition
    • Force & posture
Carpal Tunnel Syndrome (CTS)
  • Combined Risk Factors
    • Force & repetition
    • Force & posture
    • Force, repetition & posture
Hand/Wrist Tendinitis
  • Combined Risk Factors
    • High repetition & forceful hand/wrist exertion
Hand-Arm Vibration Syndrome
  • Intensity & duration to vibrational tools
    • e.g. vibrational level 5-36m/s²
Low-Back MSDs
  • Heavy physical work
  • Lifting and forceful movements
  • Bending & twisting (awkward posture)
  • Whole-body vibration (WBV)
  • Static work posture

Use checklists

Use checklists to formally screen job features against a list of risk factors. Walk through work facilities and conduct an observational survey. Observe several workers performing the same job task at the same time, to record how different workers choose postures and techniques. Interview workers and supervisors, and be sure to only gather data from those who are familiar with the job, task, or process you are investigating.

These NIOSH checklists are available for your use:

No checklist can fit all situations. You will need to customize your checklists for different job tasks or types of work. Checklists may be combined later to assess the extent of identified WMSD problems. Checklists reveal signs of individual WMSD problems that may share the same underlying cause. Use the findings from your checklists and observations of the work environment to brainstorm initial ergonomic solutions. Sometimes the solution to an WMSD problem is simple and doesn’t warrant a full-blown intervention.

Follow up on checklist observations by using additional data collection methods:

  • Measure job task and job cycle time-motion patterns
  • Measure workstation layouts
  • Measure tool handle sizes, weights, and vibration levels
  • Measure workers’ exposure to whole-body vibrations
  • Measure workers’ exposure to hot/cold conditions
  • Measure workers’ physiological and biomechanical responses to work

More details on measuring tools are provided at the end of Step 3.

TOP