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Course 750 - Introduction to Industrial Hygiene

Safety guides and audits to make your job as a safety professional easier

Ergonomic Hazards


Ergonomic Risk Factors

The science of ergonomics studies and evaluates a full range of tasks including, but not limited to, lifting, holding, pushing, walking, and reaching.

Many ergonomic problems result from technological changes such as increased assembly line speeds, adding specialized tasks, and increased repetition; some problems arise from poorly designed job tasks. Any of those conditions can cause ergonomic hazards such as excessive vibration and noise, eye strain, repetitive motion, and heavy lifting problems.

Improperly designed tools or work areas also can be ergonomic hazards. Repetitive motions or repeated shocks over prolonged periods of time as in jobs involving sorting, assembling, and data entry can often cause irritation and inflammation of the tendon sheath of the hands and arms, a condition known as carpal tunnel syndrome.

Ergonomic hazards are avoided primarily by the effective design of a job or jobsite and better designed tools or equipment that meet workers' needs in terms of physical environment and job tasks. Through worksite analysis, employers can set up procedures to correct or control ergonomic hazards by:

  • using the appropriate engineering controls (e.g., designing or re-designing work stations, lighting, tools, and equipment);
  • teaching correct work practices (e.g., proper lifting methods);
  • employing proper administrative controls (e.g., shifting workers among several different tasks, reducing production demand, and increasing rest breaks); and,
  • if necessary, providing and mandating personal protective equipment.

Evaluating working conditions from an ergonomics standpoint involves looking at the total physiological and psychological demands of the job on the worker.

Overall, industrial hygienists point out that the benefits of a well-designed, ergonomic work environment can include increased efficiency, fewer accidents, lower operating costs. and more effective use of personnel.

Ergonomic Guidelines

A major component of ergonomics is the development of industry-specific and task-specific guidelines to reduce and prevent workplace musculoskeletal disorders (MSDs). These voluntary guidelines are tools to assist employers in recognizing and controlling ergonomics-related risk factors. Employers in other industries for which guidelines have not been developed may find useful information in these guidelines for implementing their own ergonomic programs.

Current Ergonomics Guidelines

OSHA issued the ergonomic guidelines for the shipyards industry on February 28, 2008. OSHA issued the ergonomic guidelines for the poultry processing industry on September 2, 2004. OSHA issued the ergonomic guidelines for the retail grocery stores industry on May 28, 2004. OSHA issued the ergonomic guidelines for the nursing home industry on March 13, 2003. The document was updated on September 12, 2005.

Previously Completed Ergonomic Guidelines

Basic Ergonomic Principles

NOTE: For a more thorough introduction to ergonomics refer to OSHAcademy Course 711 - Introduction to Ergonomics

Ergonomics (er'gõ nom'iks):

  • The study of work and the relationship of work to the physical and cognitive capabilities of people.
  • Fitting the job (tools, tasks, and environment) to the employee, instead of forcing the worker to fit the job.

Ergonomic principles are derived from many areas, including:

  • Biomechanics
  • Physiology
  • Anthropometry
  • Industrial engineering
  • Safety

Ergonomic Injuries

Classifications of Ergonomic Injuries

There are two classifications of ergonomic injuries, and they are:

  • Cumulative Trauma Disorders (CTD's) - exposure driven
  • Strains/Sprains - instantaneous (event driven)

Characteristics of Cumulative Trauma Disorders (CTD's) are:

  • Injury to soft tissue caused by prolonged exposure to multiple ergonomic risk factors
  • Typically develop in small body segments (i.e. fingers, wrists, elbows, and neck)

Examples of CTD's

Tendon disorders:

  • Inflammation of tendon and/or tendon sheathing caused by repeated rubbing against ligaments, bone, etc.
  • Lateral epicondylitis (tennis elbow)

Nerve disorders:

  • Compression of nerves from repeated or sustained exposure to sharp edges, bones, ligaments, and/or tendons
  • Carpal tunnel syndrome

Neurovascular disorders:

  • Compression of blood vessels and/or nerves from repeated exposure to vibration or cold temperatures
  • Raynaud's phenomenon (white finger syndrome)

Characteristics of Strains & Sprains

  • Injury to connective tissue caused by single forceful event: lifting heavy objects in awkward position
  • Common to large body segments (i.e. back, legs, and shoulders)
  • Risk of injury increases with the presence of multiple risk factors

Early Reporting of Ergonomic Issues

It is critical for employees to understand the importance of reporting ergonomic issues sooner rather than later to help prevent serious injuries from occurring.

Proactive Reporting

  • Report suspected ergonomics risk factors to your supervisor and safety committee representative

Early Reporting Process

  • Report pain or discomfort associated with work to your supervisor and Occupational Health Services

Benefits to Early Reporting

  • Leads to early care and quicker healing, preventing chronic problems
  • Leads to quicker identification of the root cause of the injury
  • Will initiate an ergonomics evaluation by trained personnel

Stretching Basics

Stretching helps reduce the likelihood of ergonomic injury from occurring in the workplace.

The Benefits of Stretching

  • Increases flexibility/elasticity of muscles
  • Increases circulation to warm the muscles, improving mental alertness, reducing fatigue
  • Decreases muscle tension and stress

When to Stretch

  • Prior to starting your day
  • During short breaks (at least once per hour)
  • After breaks or lunch to prevent fatigue
  • If tension or stress is apparent
  • After a lengthy task duration or an extended awkward posture

Proper Stretching Techniques

  • Relax and breathe normally. Do not hold your breath.
  • Hold each stretch for a count of 15, or as long as comfort is maintained.
  • Use gentle, controlled motions. Do not bounce!
  • Keep the knees slightly bent for better balance.
  • Stretch until a mild tension is felt, then relax.
  • Stretch by how you feel and not by how far you can go.
Ergonomic Risk Factors
(Figure 1)
(Click to enlarge)

Ergonomic Risk Factors

The risk of injury increases with the following factors:

  • Prolonged exposure to any of the ergonomic risk factors shown in Figure 1.
  • Presence of multiple risk factors within a single job task.

Congratulations! You've completed this module and you've finished Course 750! Good luck taking the quiz and final exam.


Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. The science of ergonomics studies and evaluates a full range of tasks including, but not limited to, _____.

2. Overall, the benefits of a well-designed, ergonomic work environment can include increased efficiency, fewer accidents, lower operating costs. and more effective use of personnel.

3. Ergonomics is _____.

4. Which of the choices below are classifications of ergonomic injuries?

5. A benefit of reporting ergonomic issues sooner rather than later is _____.

6. Tonya is an employee at ABC Inc. She often sits for long periods of time and her job is stressful. If she were to stretch when appropriate some of the benefits would be _____.

7. When should you stretch?

8. Which of the below are ergonomic risk factors?

Have a great day!

Important! You will receive an "error" message unless all questions are answered.