Personal Protective Equipment

One of the most controversial questions in the prevention of MSDs is whether the use of personal equipment worn or used by the employee is effective. In the field of occupational safety and health, PPE generally provides a barrier between the worker and the hazard source. Respirators, ear plugs, safety goggles, chemical aprons, safety shoes, and protective helmets are all examples of PPE.

Whether braces, wrist splints, back belts, and similar devices can be regarded as offering personal protection against ergonomic hazards remains open to question. Although these devices may, in some situations, reduce the duration, frequency, or intensity of exposure, evidence of their effectiveness in injury reduction is inconclusive. In some instances they may decrease one exposure but increase another because the worker has to "fight" the device to perform his or her work such as the use of wrist splints while engaged in work that requires wrist bending.

According to many ergonomists and safety and health professionals, PPE is placed last in the hierarchy of risk factor controls because:

  • Its effectiveness depends on human behavior (the manager's, supervisor's and worker's);

  • Studies have shown that the effectiveness of PPE is highly variable and inconsistent from one worker to the next;

  • The protection provided cannot be measured reliably;

  • PPE must be maintained and replaced frequently to maintain its effectiveness;

  • It is burdensome for employees to wear, because it decreases mobility and is often uncomfortable; and

  • It may pose hazards of its own (e.g., the use of vibration-reduction gloves may also force workers to increase their grip strength).

Ergonomics-related PPE may include palm pads and knee pads to reduce contact stress, vibration-attenuation gloves, and gloves worn to protect against cold temperatures.

Administrative and Work Practice Controls

Administrative Controls

Administrative controls are management-dictated work practices and policies to reduce or prevent exposures to ergonomic risk factors. Administrative control strategies include (1) changes in job rules and procedures such as scheduling more rest breaks, (2) rotating workers through jobs that are physically tiring, and (3) training workers to recognize ergonomic risk factors and to learn techniques for reducing the stress and strain while performing their work tasks.

Although engineering controls are preferred, administrative controls can be helpful as temporary measures until engineering controls can be implemented or when engineering controls are not technically feasible. Administrative controls can be used to reduce the duration, frequency, and severity of exposure to ergonomic hazards. Some examples of frequently employed administrative controls include:

  • Job rotation can be used as a means to alleviate physical fatigue and stress to a particular set of muscles and tendons. To be effective, employees should be rotated to jobs that utilize different muscle-tendon groups. Job rotation in this regard is used as a preventative measure, not in response to symptoms of cumulative trauma disorders.

  • Broadening or varying the job content to offset certain risk factors (e.g., repetitive motions, static and awkward postures).

  • Shift length and overtime can have a major impact on exposure to risk factors, depending on the physical and mental demands of the job. For example, jobs requiring heavy materials handling may need shorter shift lengths. Where demand fluctuates, employees may be asked to work overtime; if the frequency or length of overtime is excessive, fatigue may result and recovery time may be reduced.

  • Frequent breaks can be incorporated into the workday to relieve fatigued muscles and to reduce stress and strain on various muscle groups.

  • Decreasing production rates and limiting overtime work are two ways to reduce the total number of repetitions per employee.

  • Adjusting the work pace to relieve repetitive motion risks and give the worker more control of the work process.

  • Increasing the number of employees assigned to a task can help alleviate severe work conditions.

  • Training in the recognition of risk factors for musculoskeletal disorders and instruction in work practices that can ease the task demands or burden.

  • Consider ergonomic strategies when developing new products and procedures. When a product is designed, consideration should be given to materials, containers for moving product and materials, fasteners, assembly access and sequence, and software interfaces.

Work Practice Controls

An effective program for ergonomic hazard prevention and control also includes safe and proper work practices that are understood and followed by managers, supervisors, and employees. Key elements of a good work practice program include instruction in proper work techniques, employee training and conditioning, regular monitoring, feedback, adjustments, modification, and maintenance.

For example, after employees are trained in a particular work activity, such as proper lifting or proper tool handling, supervisors and managers should be involved in monitoring workers to ensure that employees continue to use the proper techniques. Improper practices should be corrected to prevent injury.

Proper training with reasonable "break-in" periods for new employees or employees that have been away from the job is another work practice that can help reduce the incidence of cumulative trauma disorders. Break-in periods permit employees to build the strength needed to perform the work and reduce muscle fatigue.

Some companies have also initiated exercise periods for warming up workers at the beginning of a shift and for stretching, relaxing, and strengthening muscle groups frequently used by workers. Exercise periods help to prevent injuries by warming up cold muscles and relaxing fatigued muscles which are more susceptible to injury.

Engineering Controls | Ergonomics

The preferred means of controlling or reducing ergonomic hazards in the workplace is through the use of engineering controls. After all, the primary focus of ergonomic hazard abatement is to make the job fit the person, not force the person to fit the job. These are typically permanent controls and can be accomplished by ergonomically designing workstations, tools, or equipment.

The preferred approach to prevent and control musculoskeletal disorders is to design the job — including (1) the workstation layout, (2) selection and use of tools, and (3) work methods — to take account of the capabilities and limitations of the workforce. Engineering control strategies to reduce ergonomic risk factors include the following:

  • Changing the way materials, parts, and products can be transported.

  • Changing the process or product to reduce worker exposures to risk factors.

  • Modifying containers and parts presentation, such as height-adjustable material bins.

  • Changing workstation layout, which might include using height-adjustable workbenches.

  • Changing the way parts, tools, and materials are to be manipulated. Examples include using fixtures (clamps, vice-grips, etc.) to hold work pieces to relieve the need for awkward hand and arm positions or suspending tools to reduce weight and allow easier access.

  • Changing tool designs — for example, squeeze-grip-actuated screwdrivers to replace finger-trigger-actuated screwdrivers.

  • Changes in materials and fasteners such as lighter weight packaging materials to reduce lifting loads.

Control the Hazards | Ergonomics

Risk factors can be controlled either during the development stages of a product or process or after work has begun. In the development stages, very effective controls can be achieved (proactively) for a small investment. Once production has begun, changes can still be implemented (retrofit changes) but usually require modifications to existing equipment. Retrofit changes also require workers to change work patterns. Implementing a change after habits have been formed requires that the need, the objective, the time frame, and the consequences of the change be communicated. One way to ensure this communication is through employee involvement.

After risk factors and their causes have been identified, either in development or after implementation, the next step is to identify control measures that reduce or eliminate the presence of these factors. Traditional classification of control measures distinguishes between engineering controls and administrative controls. Opportunities for both types of controls differ depending on whether the job or process is new or existing.

A three-tier hierarchy of controls is widely accepted as an intervention strategy for controlling workplace hazards, including ergonomic hazards. These procedures should be evaluated when determining how to correct or control your ergonomic hazards:

  • Engineering controls to reduce or eliminate potentially hazardous conditions (e.g., work station, tool, and equipment design or redesign).

  • Administrative controls, usually changes in work practices and management policies (e.g., worker rotation, reduced production demand, and increased rest breaks).

  • Personal protective equipment

Worksite Analysis | Ergonomics

A worksite analysis provides for both the identification of problem jobs and risk factors associated with these jobs. The worksite analysis can be used to determine what jobs and workstations are the source of the greatest problems. Recognizing the signs that may indicate a problem through a systematic analysis of injury and illness records can be done to accomplish this step.

Analyze Company Data

First, analyze all existing medical, safety, and insurance records, including the OSHA 200 log and workers' compensation claims for evidence of ergonomic illnesses such as carpal tunnel syndrome, tendonitis, tenosynovitis, and low back pain. When you analyze the OSHA 200 log, look for these clues relating to cumulative trauma disorders associated with ergonomically hazardous jobs.

  • When the illness began (was there a lot of overtime, a speed-up in production, or introduction of new equipment around this time).

  • What is the employee's job title and department (a clue to the type of tasks being performed).

  • Column F: Description of injury or illness. Terminology given may be confusing. Some key terms for cumulative trauma disorders include arthritis, carpal tunnel, numbness, pain, strain, and tendonitis. Check your first report of injury forms for more details on questionable cases.

  • Column 7f: Disorders associated with repeated trauma. Check thoroughly. Not all repeated trauma cases are posted in this column. The descriptions in Column F are more inclusive, so always check both columns.

  • Back disorders are not listed in Column 7f. Even though they are usually due to repeated trauma, they are classified as injuries on the 200 form and must be listed in Column F. You need to check there for back-related CTDs.

This process may need to involve health care providers to ensure confidentiality of patient records.

Identify and Analyze Trends

Second, identify and analyze any apparent trends or ergonomic problems relating to particular departments, process units, production lines, job titles, operations, or workstations.

  • Certain jobs or work conditions cause worker complaints of undue strain, localized fatigue, discomfort, or pain that does not go away after overnight rest.

  • Workers visiting the clinic make frequent references to physical aches and pains related to certain types of work assignments.

  • Job tasks involve activities such as repetitive overhead lifts; awkward work positions; or use of vibrating equipment.

A company's initial efforts in ergonomics should be directed toward fixing the most obvious problem jobs. Implementing the program can have value by enabling early detection of and more timely interventions in potential ergonomic problems. Also, an ergonomics program can influence the design of future changes in work processes to reduce the possibility of musculoskeletal disorders.

This information will provide you with an idea about where "problem jobs" exist. Worker surveys and a background knowledge of certain jobs considered "high risk" can also help in targeting specific worksite analyses. Employee questionnaires on ergonomic problems and issues are a useful way to gather information about work conditions that may contribute to ergonomic hazards. Other forms of regular employee participation might include a complaint log or a suggestion book.

Determine Risk Factors

The next step to take is conducting a more detailed analysis of those job tasks and positions determined to be problem areas for their own specific ergonomic risk factors. This analysis can be done with a checklist and should be performed either by direct observation or, where feasible, through videotape review. The analysis should be routinely performed and documented by a qualified person, ideally an ergonomist, although trained engineers, managers, health care providers, and affected employees can often contribute significantly to the process.

A combination of risk factors rather than any single factor may be responsible for the occurrence of musculoskeletal disorders. Therefore, identifying all the risk factors that may be present in the job is important. Some typical risk factors for cumulative trauma and back disorders that are likely to be identified in a worksite analysis include:

  • Excessive repetition or prolonged activities such as for an 8-hour shift, cause fatigue and muscle/tendon strain which can accumulate and may result in permanent tissue damage.

  • Forceful exertions (including lifting, pushing, and pulling) place higher loads on the muscles, tendons, and joints. As the force increases, the muscles fatigue more quickly.

  • Pinch grips which usually place three to four times more force on the tendons than power grips.

Postures determine which muscles are used in an activity and how forces are translated from the muscles to the object being handled. More muscular force is required when awkward postures are used because muscles cannot perform efficiently.

Look for these postures when analyzing a task:

  • Prolonged static postures of the body, trunk or its extremities, either sitting or standing.

  • Awkward postures of the upper body, including reaching above the shoulders or behind the back.

  • Excessive bending or twisting of the hand or wrist.

  • Continued elevation of the elbow and forearm.

  • Continued physical contact with work surfaces, such as contact with edges of machines can inhibit nerve function and blood flow.

  • Inappropriate or inadequate hand tools that cause awkward posturing.

  • Restrictive workstations and inadequate clearances that may cause stooping and bending.

  • Improper seating or support.

  • Bad body mechanics such as continued bending at the waist, continued lifting below the knuckles or above the shoulders, or twisting at the waist while lifting.

  • Lifting heavy objects or objects of abnormal sizes without mechanical aids.

  • Lack of adjustable chairs, footrests, body supports, and work surfaces at workstations or slippery footing.

Perform the Job Analysis

Job analysis breaks a job into its various elements or actions, describes them, measures and quantifies risk factors inherent in the elements, and identifies conditions contributing to the risk factors. Most job analyses have several common steps. Each task is studied to determine the specific risk factors that occur during the task. Sometimes each risk factor is evaluated in terms of its magnitude, that is, the number of times it occurs during the task, and how long the risk factor lasts each time it occurs.

The tasks of most jobs can be described in terms of (1) the tools, equipment, and materials used to perform the job, (2) the workstation layout and physical environment, and (3) the task demands and organizational climate in which the work is performed. Job screening provides some of this data. More definitive procedures for collecting information on these components can include the following:

  • Observing the workers performing the task in order to furnish time-activity analysis and job or task cycle data; videotaping the workers is typically done for this purpose.

  • Still photos of work postures, workstation layouts, tools, etc., to illustrate the job.

  • Workstation measurements (e.g., work surface heights, reach distances).

  • Measuring tool handle sizes, weighing tools and parts, and measuring tool vibration and part dimensions.

  • Determining characteristics of work surfaces such as slip resistance, hardness, and surface edges.

  • Measuring exposures to heat, cold, and whole body vibration.

  • Biomechanical calculations (e.g., muscle force required to accomplish a task or the pressure put on a spinal disc based on the weight of a load lifted, pulled or pushed).

  • Physiological measures (e.g., oxygen consumption, heart rate).

  • Special questionnaires, interviews, and subjective rating procedures to determine the amount of perceived exertion and the psychological factors influencing work performance.

Jobs in which current cases have been identified should receive immediate attention, followed by those in which past records have noted a high incidence or severity of musculoskeletal disorders despite the lack of current cases. Priority for job analysis and intervention should be given to those jobs in which most people are affected or in which work method changes are going to be taking place anyway.

The analysis should take multiple causes into consideration, as the combined effect of several risk factors often results in the onset of cumulative trauma disorders. Jobs, operations, or workstations that have multiple risk factors have a higher probability of causing these disorders.

Ideally, all risk factors within a problem area should be identified and proper controls implemented to eliminate each of them. The goal of an ergonomic approach is to make things better than they were before. Incremental improvements in reducing or eliminating some, if not all, risk factors within a problem area will reduce the cumulative risk and the overall level of physical stress for the worker. Thus, the benefits of hazard prevention and control strategies can be quite significant.

Develop an MSD Reporting System

There should be a method/system for employees to report MSD signs and symptoms and to get prompt responses. It may take either a formal or informal approach. Large employers may decide that a formal system of reporting that includes written documentation is appropriate to ensure that nothing falls through the cracks. Employers with fewer than ten employees, on the other hand, may find that oral reporting systems are adequate.

Your company probably has an injury and illness reporting system in place that can be adapted to accommodate MSD reporting. Regardless of how methods are tailored to meet the needs of a specific workplace and workforce, the process must be systematic and accessible to all employees.

A reporting system is important for a successful ergonomics program. In order for you to know that MSDs are occurring, employees must have a mechanism for reporting this information. A system that is well-known to employees is one way to ensure employee participation in the ergonomics program.

It's a good idea to designate at least one person to receive and respond to employee reports, and to take appropriate action. Depending on the workplace, that responsibility may be designated to front-line supervisors, a safety officer or safety committee, an occupational health nurse, or in small companies, the employer may encourage workers to report MSD signs and symptoms directly to him or her.

Build In-House Expertise

Training is recognized as an essential element for any effective safety and health program. For ergonomics, the overall goal of training is to enable managers, supervisors, and employees to identify aspects of job tasks that may increase a worker's risk of developing musculoskeletal disorders, recognize the signs and symptoms of the disorders, and participate in the development of strategies to control or prevent them. Training ensures that everyone involved is well informed about the hazards so they can actively participate in identifying and controlling exposures.

Ergonomics awareness training objectives should include:

  • Recognize workplace risk factors for musculoskeletal disorders and understand general methods for controlling them.

  • Identify the signs and symptoms of musculoskeletal disorders that may result from exposure to risk factors, and be familiar with the company's health care procedures.

  • Know the process the employer is using to address and control risk factors, the employee's role in the process, and ways employees can actively participate.

  • Know the procedures for reporting risk factors and musculoskeletal disorders, including the names of designated persons who should receive the reports.

Job analysis and control measures training objectives should include:

  • Demonstrate the way to do a job analysis for identifying risk factors for musculoskeletal disorders.

  • Select ways to implement and evaluate control measures.

Problem solving training objectives include:

  • Identify the departments, areas, and jobs with risk factors through a review of company reports, records, walk-through observations, and special surveys.

  • Identify tools and techniques that can be used to conduct job analyses and serve as a basis for recommendations.

  • Develop skills in team building, consensus development, and problem solving.

  • Recommend ways to control ergonomic hazards based on job analyses and pooling ideas from employees, management, and other affected and interested parties.

Training objectives are not intended to have workers, supervisors, or managers diagnose or treat ergonomic-related disorders. Rather, the purpose is to instill an understanding of what type of health problems may be work related and when to refer employees for medical evaluation. The training should include what is known about work and non-worker causes of musculoskeletal disorders and the current limitations of scientific knowledge.

Training should be understandable to the target audience and the materials used should consider the participants' education levels, literacy abilities, and language skills. This may mean providing materials, instruction, or assistance in languages other than English.

Open and frank interactions between trainers and trainees, especially those in affected jobs, are especially important. Employees know their own jobs better than anyone else and often are the source of good ideas for ways to improve them. At a minimum, employees must be given an opportunity to discuss ergonomic problems in their jobs as they see them and engage in relevant problem-solving exercises during the training.

Audit the Ergonomics Program

A comprehensive ergonomics program audit is also essential to periodically evaluate the whole set of safety and health management methods and processes to ensure that they protect against potential ergonomic hazards at a specific worksite. The audit determines whether policies and procedures are implemented as planned and whether, in practice, they have met the objectives set for the program.

Performing an audit will ensure that the overall ergonomics effort is consistent with the priorities and goals of your organization. Include accounting and engineering activities as well as safety in your audit. An ergonomic audit should focus on these areas.

  • Identification of existing and potential problems.

  • Ergonomic assessment of jobs with possible problems.

  • Correction for and prevention of ergonomic problems.

  • Medical management.

  • Ergonomics training at all employee levels.

  • Organizational issues and management.

When either performance or the objectives themselves are found inadequate, revisions to the program should be made. Without such a comprehensive review, its impossible to gage the effectiveness of the ergonomic controls you've implemented.

Management Commitment and Employee Involvement

The first step in implementing an ergonomics program is to gain the support of both management and employees. Commitment and involvement are complementary and essential elements of a sound safety and health program. Commitment by management provides the organizational resources and motivating forces necessary to deal effectively with ergonomic hazards. An ergonomics program in the workplace is likely to fail without commitment from management.

Employee involvement and feedback through clearly established procedures are likewise essential, both to identify existing and potential hazards and to develop and implement an effective way to abate all kinds of ergonomic hazards.

Management Commitment

To fulfill the ergonomics program's goals, it is essential that the employer demonstrate leadership by developing ways for employees to report MSDs, respond to those reports, and be involved in the overall ergonomics program. Ensure that your company's policies or practices do not discourage employees from reporting MSD signs or symptoms or from participating in the ergonomics program. To be effective, management leadership must be active rather than passive.

A successful program should take a team approach, and include the following:

  • Management's involvement demonstrated through personal concern for employee safety and health by placing a priority on eliminating the ergonomic hazards.

  • A policy that places safety and health on the same level of importance as production. To accomplish this, production processes and safety and health protection should be integrated to assure that this protection is part of the daily production activity within each facility.

  • The commitment of the employer to assign and communicate responsibility for various aspects of the ergonomics program so that everyone knows what is expected of them.

  • The commitment of adequate authority and resources so that the program can be properly implemented.

  • Employer commitment to ensure that each manager, supervisor, and employee responsible for the ergonomics program is accountable for carrying out those responsibilities.

Employee Involvement

Management leadership and employee involvement are complementary as well as essential to the success of an ergonomics program. Employees' intimate knowledge of the jobs they perform and the special concerns they bring to their job give them a unique perspective that can be used to make the program more effective.

Employee participation provides the means through which workers develop and express their own commitment to safe and healthful work, as well as sharing in the overall success of the company. Employees must have:

  • A way to report MSD signs and symptoms;

  • Prompt responses to their reports;

  • Information about the ergonomics program; and

  • Ways to be involved in developing, implementing and evaluating each element of the ergonomics program.

Form a Committee

One form of employee participation in an organization's efforts to reduce work-related injuries is through a joint labor-management safety and health committee, which may be company-wide or department-wide. Membership on company-wide committees includes union leaders to elected worker representatives, department heads, and key figures from various areas of the organization. At this level, typical committee functions consist of:

  1. Discussing ways to resolve safety and health issues;

  2. Making recommendations for task forces or working groups to plan and carry out specific actions; and

  3. Approving use of resources for such actions and providing oversight.

Committee make-up and function at the department level are more localized, since they are directed to issues specific to their own operations. Composition here can be limited to workers from the department or area engaged in similar jobs who, with their supervisors and select others (e.g., maintenance), propose ways for reducing work-related problems, including those posing injury or disease risks. Because of their smaller size and opportunities for closer contacts among members, such committees may be referred to as a work group. The department or area work group approach appears to be a popular one in addressing ergonomic problems.

Involve People From all Over the Company

Ergonomic problems typically require a response that cuts across a number of organizational units. Hazard identification through job task analyses and review of injury records or symptom surveys, as well as the development and implementation of control measures, can require input from:

  • Safety and hygiene personnel,

  • Health care providers,

  • Human resource personnel,

  • Engineering personnel,

  • Maintenance personnel, and

  • Ergonomics specialists.

In small businesses, two or more of the functions noted on the list may be merged into one unit, or one person may handle several of the listed duties. Regardless of the size of the organization, persons identified with these responsibilities are crucial to an ergonomics program. Purchasing personnel in particular should be included, since the issues raised can dictate new or revised specifications on new equipment orders.

How best to fit these different players into the program may depend on the company's existing occupational safety and health program practices. No single form or level of worker involvement fits all situations or meets all needs. Much depends on the nature of the problems to be addressed, the skills and abilities of those involved, and the company's prevailing practices for participative approaches in resolving workplace issues.

Employee involvement, however, is only effective when the employer welcomes it and provides protection from any discrimination to the employees involved. Inclusion of employees in labor-management committees, safety circle teams, rotational assignments, or in other ways that provide the employee with an opportunity to impact decisions about safety and health protection will strengthen the program for ergonomic hazard protection.

Tackling Ergonomic Hazards | Ergonomics

The first step in setting up an ergonomics program is to determine if musculoskeletal disorders are present. Recognizing the signs that a problem exists is the first step. Some signs are obvious while others are more subtle. Look for signs such as the following:

  • OSHA Form 200 logs or workers' compensation claims show cases of MSDs such as carpal tunnel syndrome, tendinitis, tenosynovitis, epicondylitis, and low back pain. Sometimes these records contain nonspecific entries like "hand pain," which, while not a specific diagnosis, may be an indicator of a significant health problem if severe or persistent.

  • Certain jobs or work conditions cause worker complaints of undue strain, localized fatigue, discomfort, or pain that does not go away after overnight rest.

  • Workers visiting the clinic make frequent references to physical aches and pains related to certain types of work assignments.

  • Job tasks involve activities such as repetitive and forceful exertions; frequent, heavy, or overhead lifts; awkward work positions; or use of vibrating equipment.

Other signals that alert employers to potential problems include the following:

  • Trade publications, employers' insurance communications, and references in popular literature indicating risks of MSDs connected with job operations in the employer's business.

  • Cases of MSDs found among competitors or in similar businesses.

  • Proposals for increasing line speed, retooling, or modifying jobs to increase individual worker output and overall productivity.

Clues that indicate ergonomic problems may also suggest the scope of the effort required to correct them. Signs that implicate multiple jobs in various departments and involve a large percent of the workforce may indicate the need for a full-scale, company-wide program. Signs that the suspected problems are confined to isolated tasks and relatively few workers may suggest starting with a more limited, job-focused activity.

The financial benefits of comprehensive safety and health programs have been well documented. Workplaces safe from hazardous conditions have lower costs due to decreased lost time, absenteeism, and worker compensation premiums. Ergonomics programs have been shown to be cost effective for similar reasons. In addition, ergonomic improvements may result in increased productivity and higher product quality.

Risk Factors that Cause MSDs | Ergonomics

The physical stresses that can contribute to or cause MSDs are called "risk factors." The initial symptoms of MSDs may include fatigue, discomfort, and pain; as tissue damage worsens, other symptoms, such as weakness, numbness, or restricted movement, may also appear. Work-related MSDs occur when the risk factors that cause or contribute to musculoskeletal system pathology are associated with a person's job duties. Workplace musculoskeletal disorders are caused by exposure to the following risk factors:


Doing the same motions over and over again places stress on the muscles and tendons. The severity of risk depends on how often the action is repeated, the speed of movement, the number of muscles involved, and the required force.

Forceful Exertions

Force is the amount of physical effort required to perform a task, such as heavy lifting or pushing/pulling, or to maintain control of equipment or tools. The amount of force depends on the type of grip, the weight of an object, body posture, the type of activity, and the duration of the task.

Awkward Postures

Posture is the position your body is in and affects muscle groups that are involved in physical activity. Awkward postures include repeated or prolonged reaching, twisting, bending, kneeling, squatting, working overhead with your hands or arms, or holding fixed positions.

Contact Stress

Pressing the body against a hard or sharp edge can result in placing too much pressure on nerves, tendons, and blood vessels. For example, using the palm of your hand as a hammer can increase your risk of suffering an MSD.


Operating vibrating tools or equipment that typically have high or moderate vibration levels such as sanders, grinders, chippers, routers, drills, and other saws can lead to nerve damage.

Don't Wait to Start an Ergonomics Program

Data shows that employers with effective, well-managed ergonomics programs see significant reductions in the severity and number of work-related MSDs. These programs also generally improve productivity and employee morale and reduce turnover and absenteeism.

Even though OSHA's ergonomics standard has been rescinded, your workers' safety and health and rising workers' compensation claims are reason enough for you to carefully analyze your company's work environment, the equipment used, and the tasks performed from an ergonomics perspective. If you do not feel competent to make the evaluation, bring in outside assistance. There are various government and private agencies that are capable of doing a workplace analysis.

Common MSDs | Ergonomics

The most common MSDs in the workplace are tendon disorders such as tendinitis, tenosynovitis, De Quervain’s disease, trigger finger, Raynaud’s syndrome, and carpal tunnel syndrome. Tendon disorders often occur at or near the joints where the tendons rub against ligaments and bones. The most frequently noted symptoms of tendon disorders are a dull aching sensation over the tendon, discomfort with specific movements, and tenderness to the touch. Recovery is usually slow and the condition may easily become chronic if the cause is not eliminated.


Tendinitis is tendon inflammation that occurs when a muscle or tendon is repeatedly tensed from overuse, vibration, or unaccustomed usage of the wrist and shoulder. With further exertion, some of the fibers that make up the tendon can actually fray or tear apart. The tendon becomes thickened, bumpy, and irregular in certain areas of the body, such as the shoulder, and the injured area may calcify. Without rest and sufficient time for the tissues to heal, the tendon may be permanently weakened. Tendinitis is common among power press operators, welders, painters, and assembly line workers in the automobile, appliance, and electronic production industries.


Tenosynovitis is an inflammation or injury to the synovial sheath surrounding the tendon. These sheaths secrete synovial fluid which acts as a lubricant to reduce friction during movement. Repetitive motion using the hands and wrists may provoke an excessive secretion of synovial fluid, with the sheath becoming swollen and painful. Repetitions exceeding 1,500 to 2,000 per hour are known to produce symptoms associated with tendon sheath irritation in the hands. Tenosynovitis often affects workers in meatpacking and poultry processing. Also those whose tasks require buffing, grinding, sanding, sawing, and punch press operations.

DeQuervain's Disease

In DeQuervain’s disease, the tendon sheath of the thumb is inflamed. This disease is attributed to excessive friction between two thumb tendons and their common sheath. Twisting and forceful gripping motions with the hands, similar to a clothes-wringing movement, can place sufficient stress on the tendons to cause DeQuervain’s disease. Tasks involving these kinds of motions are frequently performed by butchers, housekeepers, packers, seamstresses, and cutters.

Trigger Finger

Trigger finger, another tendon disorder, is attributed to the creation of a groove in the flexing tendon of the finger. If the tendon becomes locked in the sheath, attempts to move that finger will cause snapping and jerking movements. The palm side of the fingers is the usual site for trigger finger. This disorder is often associated with using tools that have handles with hard or sharp edges or whose handles are too far apart for the user’s hand. Meatpackers, poultry workers, electronic assemblers, and carpenters are at risk of developing trigger finger.

Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS), a disorder affecting the hands and wrists, has probably received more attention in recent years than any other musculoskeletal disorder. CTS is the compression and entrapment of the median nerve where it passes through the wrist into the hand in the carpal tunnel. The median nerve is the main nerve that extends down the arm to the hand and provides the sense of touch in the thumb, index finger, middle finger, and half of the fourth or ring finger.

When irritated, tendons housed inside the narrow carpal tunnel swell and press against the nearby median nerve. The pressure causes tingling, numbness, or severe pain in the wrist and hand. The pain is often experienced at night. The pressure also results in a lack of strength in the hand and an inability to make a fist, hold objects, or perform other manual tasks. If the pressure continues, it can damage the nerve, causing permanent loss of sensation and even partial paralysis.

Carpal tunnel syndrome develops in the hands and wrists when repetitive or forceful manual tasks are performed over a period of time. Workers need to be aware of the symptoms and causes of CTS and what to do about them. Initially, they may have fatigue and pain which develops during the work day and disappears overnight with no physical symptoms. After a length of time, fatigue and pain develop earlier in the day, some physical symptoms such as clumsiness may occur which affect work performance, and there may be no overnight recovery.

When the case becomes full-blown, there is constant fatigue and pain with no overnight recovery and disturbed sleep results. At this point, work performance is inhibited to the extent of requiring off-duty time or light/restricted duty. Often workers do not associate their pain with their work because symptoms may only occur during evening or off-duty hours. When they finally seek medical help, surgery may be necessary and the road to recovery will take more time than anticipated.

Raynaud's Syndrome

Raynaud’s syndrome, or white finger, occurs when the blood vessels of the hand are damaged as a result of repeated exposure to vibration for long periods of time. The skin and muscles are unable to get the necessary oxygen from the blood and eventually die. Common symptoms include:

  • Intermittent numbness and tingling in the fingers;

  • Skin that turns pale, ashen and cold; and

  • Eventual loss of sensation and control in the fingers and hands.

Raynaud’s syndrome is associated with the use of vibrating tools over time, such as pneumatic hammers, electric chain saws, and gasoline powered tools. After long-term exposure, the blood vessels in the fingers may become permanently damaged. This condition is also intensified when the hands are exposed to extremely cold temperatures.

There is no medical remedy for white finger. If the fingers are fairly healthy, the condition may improve if exposure to vibration stops or is reduced. Job activities that can lead to Raynaud’s Syndrome include chain sawing, jack hammering, use of vibrating tools, sanding, painting, and using a tool too small for the hand, often in a cold environment.

Other types of vibration may affect the entire body, producing overall fatigue and potential permanent damage. Vibration in conjunction with prolonged sitting may also result in degenerative changes in the spine. For example, drivers of tractors, trucks, buses, construction machinery, and other heavy equipment may suffer from low back pain, and permanent abdominal, spinal and bone damage.

Back Disorders

Pulled or strained muscles, ligaments, tendons, and disks are perhaps the most common back problems and may occur in almost half of the work force at least once during their lifetime. The majority of workplace back disorders result from chronic, or long-term injury to the back rather than from one specific incident. Only about four percent of back injuries are associated with a single traumatic incident.

Back disorders are frequently caused by the cumulative effects of faulty body mechanics:

  • Excessive or repetitive twisting, bending, and reaching;

  • Carrying, moving, or lifting loads that are too heavy or too large;

  • Staying in one position for too long;

  • Poor physical condition; or

  • Awkward posture.

When back muscles or ligaments are injured from these repetitive pulling and straining activities, the back muscles, disks, and ligaments can become scarred and weakened and lose their ability to support the back, making additional injuries more likely.

Prolonged sitting stresses the body, particularly the lower back and the thighs, and may cause the lower back (lumbar) region to bow outward if there is inadequate support. This abnormal curvature (called kyphosis) can lead to painful lower back problems, a common complaint among office workers.

Other factors which are contributors to back injuries include the natural degeneration of the back due to aging, inactivity both at work and at home, seasonal activity undertaken without prior physical conditioning, stress, and vibration.

What are Musculoskeletal Disorders?

Musculoskeletal disorders are caused or aggravated by repetitive motions, forceful exertions, vibration, mechanical compression (hard and sharp edges), and sustained or awkward postures that occur over extended periods of time. MSDs can affect nearly all tissues, the nerves, tendons, tendon sheaths, and muscles, with the upper extremities being the most frequently affected. These injuries range from disorders of the back, the neck, the arms and legs, or the shoulders and involve strains, sprains, or tissue inflammation, and dislocation.

Workers suffering from MSDs may experience less strength for gripping, less range of motion, loss of muscle function, and inability to do everyday tasks. These painful and sometimes crippling injuries develop gradually over periods of weeks, months, and years as the result of the repeated actions required to perform their jobs.

Awareness is the key to preventing serious MSD injuries. It is important for employers and employees alike to know the signs and symptoms of MSDs. These signs and symptoms are often ignored, because they seem slight at first and go away when the employee is not at work. However, as time goes on, the symptoms increase and last longer until finally it’s impossible to perform simple tasks such as holding a drinking glass or keyboarding. Early intervention is essential to recovery.

That’s why it’s important to train employees about MSD signs and symptoms and encourage them to report symptoms as soon as they become aware of them. They also need to understand what may happen if they continue to perform their regular job and don’t report the symptoms. Early reporting is essential to lessen the severity of the injury. The longer warning signs are ignored, the more damage is done, the longer recovery takes, and in some cases, the damage can’t be repaired.

Signs and Symptoms

The presence of MSD signs and/or symptoms is usually the first indication that an employee may be developing an MSD. The signs are objective physical findings that an MSD may be developing. The symptoms, on the other hand, are physical indications that an employee may be developing an MSD.

Symptoms can vary in severity, depending on the amount of exposure to MSD hazards and often appear gradually, for example, as muscle fatigue or pain at work that disappears during rest. Usually symptoms become more severe as exposure continues. If the employee continues to be exposed, symptoms may increase to the point that they interfere with performing the job. Finally, pain may become so severe that the employee is unable to perform physical work activities).

Signs that may indicate an MSD include deformity, decreased grip strength, decreased range of motion, and loss of function. Common symptoms of MSDs include:

  • Painful joints,

  • Pain, tingling, or numbness in the hands or feet,

  • Shooting or stabbing pains in the arms or legs,

  • Swelling or inflammation,

  • Burning sensation,

  • Pain in wrists, shoulders, forearms, or knees,

  • Fingers or toes turning white,

  • Back or neck pain, and

  • Stiffness.

State-Plan States Move Forward with Ergonomics Rules

California—Title 8, Section 5110, Ergonomics Rule

The State of California Department of Industrial Relations began to develop the nation’s first rule addressing repetitive motion injuries in the mid-1990s. The rulemaking was mandated by a provision in a workers’ compensation bill passed by the California Legislature in 1993 which required that the Cal/OSHA Standards Board promulgate an ergonomics standard designed to prevent injuries caused by repetitive motion. In November 1996, Section 5110, Repetitive Motion Injuries, a new section to the California Title 8, General Industry Safety Orders was adopted.

The standard applies repetitive motion injuries that are work-related (50 percent or more of the worker’s job) which have been identified and diagnosed by a licensed physician. Covered employers must establish and implement a program that includes a worksite evaluation, control of exposures which have caused repetitive motion injuries, and training for employees. Employers with nine or fewer employees are exempted. Since the rule became effective on July 3, 1997, Cal/OSHA has issued several citations under it.

Washington—Part 296-62-05101

Following California’s lead, in May 2000, the state of Washington became the country’s second state to adopt its own ergonomics rule. To ensure that the rule will work correctly before any enforcement occurs, the Department of Labor and Industries (LandI) implemented voluntary demonstration projects prior to enforcement.

The ergonomics rule requires employers to evaluate jobs to identify potential ergonomic risks such as awkward posture, frequent or heavy lifting, hand-arm vibration, force, or highly repetitive motion. Employers will have to reduce employee exposure when it is determined that jobs meet these risk factors and provide basic ergonomics education for employees who work in or supervise high risk jobs.

Revised: 2002/10
The rule is being phased in over a five year period, beginning in July 2002. Implementation dates range from July 1, 2002 through July 1, 2006, but enforcement will be delayed until July 2004. The two-year enforcement delay means that LandI will impose no penalties under the rule for two years after each effective date on the timeline.


Revised: 2002/10

Alaska’s Department of Labor and Workforce Development has held state-wide meetings to get public input on developing regulations for several safety and health issues, including ergonomics. The Department will evaluate and incorporate public input from these meetings into draft regulations, and propose in a formal rulemaking process.


Revised: 2002/10

In February 2002, Minnesota legislators introduced bills that would require the state’s commissioner of labor and industry to adopt a standard regulating workplace ergonomic hazards. The bills mandate rules addressing ergonomic risk factors for awkward postures; force; repetitive motions; repeated impacts; heavy, frequent, or awkward lifting; and vibration. They would cover all industries where workers are exposed to workplace ergonomic hazards and where there are economically and technologically feasible measures to control these hazards. In June, the Minnesota Department of Labor and Industry established a task force to review the state’s current approach to ergonomic issues and make recommendations for future actions.

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