Key points
Learn about what jobs have the highest risk of work-related musculoskeletal disorders (WMSDs), what workplace conditions may increase risk, and how you can screen for risks.
Learn who is at risk
Work-related musculoskeletal disorders (WMSDs) and injuries can happen to anyone. 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.
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). They can also calculate prevalence rates (i.e., new and old cases) of WMSD problems. This comes in handy for Step 3.
Here are some specific ways to look for work records that may indicate a risk.
- Specific cases, such as carpal tunnel syndrome or tendinitis. Nonspecific cases, such as hand/wrist pain or back pain.
- Complaints of undue stress, localized muscle fatigue, discomfort, pain that does not go away after rest.
- Mentions of physical aches and pains related to certain types of work assignments.
- Job tasks such as repetitive and forceful exertions or use of vibrating equipment.
- Evidence that job/task modifications (like increasing line speed) were proposed specifically to increase worker output and overall productivity.
- Evidence of WMSDs in the field.
Identified a possible WMSD?
You can also search for HHE reports on WMSDs on the HHE website. Possible key words to search for include "ergonomics" or "musculoskeletal disorders."
Learn about workplace conditions that can increase risk
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 exertion from your muscles, tendons, nerves, and bones. This limit to range of motion and exertion can lead to WMSDs. Additionally, maintaining the same position for an extended period of time can cause additional muscle fatigue and disrupt blood flow. This can even occur for neutral positions.
Examples of physical risk factors for WMSDs
- Awkward postures
- Overhead work
- Twisting and carrying loads
- Contact stress
- Poor shoulder and wrist posture
- Lifting bulky loads
- Whole body vibration
Many risk factors and conditions contribute to WMSDs. Frequently there can be more than one risk factors present such as contact stress and excessive force while pushing a cart.
Psychosocial stress risk factors
Psychosocial stress can also affect the wellbeing of workers. Psychosocial stress results from several factors including:
Work organization factors
- Fatiguing workload
- Repetitiveness
- Lack of job control
- Extreme mental demand
- Low job satisfaction
Factors outside the workplace
- Parental responsibilities
- State of personal health
- Financial concerns
Individual worker factors
- Genetic factors
- Educational status
- Culture
- Personality traits
Learn what jobs and tasks may put you at risk for WMSDs
To identify job tasks that put workers at risk for WMSD problems, lay the groundwork for early intervention and prevention.
A single job task or setting may present more than one risk factor for WMSDs. The level of risk for workers developing WMSDs depends on many elements of the work task including:
- Intensity
- Frequency
- Duration
The U.S. Bureau of Labor Statistics provides data on occupations with physical requirements. These requirements may become risk factors for WMSDs if the work tasks include high intensity, frequency, or duration.
The Occupational Requirement Survey grades work-related strenuousness at five levels: sedentary, light, medium, heavy, and very heavy.
NIOSH Worker Health Charts
NIOSH Worker Health Charts are based on the National Health interview Survey (NHIS) data from the 2015 Occupational Health Supplement. Each figure contains an occupation's 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. All are listed by occupation.
Unadjusted Prevalence of Frequent Lifting, Pushing, Pulling, or Bending: 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%.
Unadjusted Prevalence of Frequent Standing or Walking: 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%.
Unadjusted Prevalence of Low Back Pain Attributed to Work: 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%.
Unadjusted Prevalence of Current Carpal Tunnel Syndrome Attributed to Work: 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%.
Specific musculoskeletal disorders and their risk factors
NIOSH 1997 Publication reviewed specific WMSDs in relationship to risk factors from literature reviews. During that time, WMSDs 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 have strong or some evidence contributing to those specific WMSDs.
- 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)
- Repetitive work (repetition with awkward shoulder posture)
- Static shoulder load (contact stress)
- Overhead work
- Forceful work (wrist generates force stress on elbow)
- Combined risk factors: Force and repetition, force and posture
- Force and repetition
- Force and posture
- Force, repetition, and posture
- Combined risk factors:
- High repetition and forceful hand/wrist exertion
- Intensity & duration to vibrational tools, e.g. vibrational level 5-36m/s²
- Heavy physical work
- Lifting and forceful movements
- Bending & twisting (awkward posture)
- Whole-body vibration (WBV)
- Static work posture
Use checklists to screen for risks
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 , only gather data from those who are familiar with the job, task, or process.
NIOSH checklists
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.
Additional data
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.