Welcome to the training session on ergonomics in industrial work areas. This session will look at some of the basic principles of ergonomics so that you can use a commonsense approach to working safely. In particular, the information presented here will focus on musculoskeletal disorders, or MSDs, and how ergonomics helps prevent them.

Session Objectives

This session has several objectives. By the end of it, you will be able to:

• Understand the principles of ergonomics;
• Recognize the risk factors, signs, and symptoms of musculoskeletal disorders, or MSDs;
• Understand our program for identifying, reporting, and controlling MSDs; and
• Know how to protect yourself from MSD injuries and reduce your risk of getting them.

 What is Ergonomics?

What is Ergonomics?

• Ergonomics is the science of modifying jobs to fit the capabilities of the people who do them. Work-related MSDs result when there is a mismatch between the physical capability of workers and the physical demands of their jobs. Ergonomics helps resolve this mismatch.
• Ergonomics helps reduce MSDs that can result when the worker’s job requires repetitive reaching, using forceful exertions, bending and lifting, working with vibrating equipment, or other repetitive motions.
• Ergonomic engineering controls may change the design of a work-station, a production line, or the way a job is performed for the purpose of reducing MSDs.
• Ergonomics may introduce safe work practices, such as providing alternative tasks or allowing workers to rotate through different types of jobs throughout the day so that their exposure to risk factors is reduced.
• Finally, ergonomic personal protective equipment, or PPE, may be used to provide additional protection from MSDs.

Musculoskeletal Disorder (MSD) Injuries

MSD injuries are a serious problem in the workplace.

• The federal Occupational Safety and Health Administration, or OSHA, estimates that 1.8 million workers each year report work-related MSDs such as carpal tunnel syndrome, tendinitis, and back injuries.
• About 600,000 of these MSD injuries are serious enough to require workers to take time off work in order to recover.

Ergonomics, if implemented effectively, will reduce these numbers.

OSHA Regulation of Ergonomics

OSHA’s regulation of ergonomics and MSDs does not stem from a specific rule, but rather from what is known as the “General Duty Clause” of the Occupational Safety and Health Act.

The General Duty Clause is a federal statute that requires employers to provide a workplace that is “free from recognized hazards that are causing or are likely to cause death or serious physical harm.”

• The General Duty Clause applies to unregulated hazards—that is, hazards that are recognized as existing, but for which there is no specific standard. In other words, an unsafe condition that is not covered by one of OSHA’s specific standards is considered to be covered by the General Duty Clause if:

– There is a failure by the employer to keep a hazard-free workplace;

– The hazard is recognized as a hazard by the employer or the employer’s industry in general;

– The hazard is causing, or is likely to cause, death or serious harm; and

– A feasible and useful method exists to correct the hazard.

MSD-Type Injuries

What are MSDs? Generally they are injuries or illnesses of the soft tissue and nervous system that affect your body’s muscles; nerves; and tendons.

• About 63% of MSD injuries occur from repetitive motion,
• 20% are from repetitive placing or grasping, or moving objects,
• 9% are from typing or key entry, and
• 8% are from repetitive use of tools.

Characteristics of MSDs

Here are the common characteristics of MSDs:

• They may occur either from a single event—such as a strain or a sprain—or they may result from gradually increasing tissue damage from many small injuries;
• They take weeks, months, or even years to develop;
• They produce no symptoms in their early stages, but show symptoms later after injury has already occurred;
• Contributing causes of MSDs may be present both at work and in the home or during recreational activity; and
• The same MSD may differ in severity from person to person, even if they have been doing similar tasks for similar periods of time.

General Signs of MSDs

Some of the general signs of MSDs include:

• Less strength for gripping—you may have trouble gripping a steering wheel or holding a pen to write a check.
• Less range of motion—you may find that you can’t lift your arm as high as you could before.
• Loss of muscle function—for example, you may have trouble flexing your fingers.
• Or, inability to do everyday tasks, such as holding a pencil or gripping a glass of water.

MSD Symptoms

MSD symptoms may include the following:

• Your back and neck may experience shooting pains or prolonged stiffness;
• Your shoulders may experience pain, stiffness, or loss of mobility;
• Your arms and legs might have periods of shooting or stabbing pains, or a feeling of numbness; or
• Your elbow or knee joints could have pain, swelling, stiffness, or soreness.

Understanding and recognizing the signs and symptoms of MSDs as described on this and the previous slide can help you prevent them. The first step is to reduce your exposure to risk factors that may cause MSD signs and symptoms. Remember that an MSD can cause pain or discomfort in a number of body parts and that the type of discomfort you experience depends on the type of MSD.

MSD Symptoms (cont.)

Some additional possible MSD symptoms include:

• Hands and wrists may experience various symptoms such as swelling, numbness, or loss of strength.
• Fingers may experience such symptoms as jerking movements, loss of strength, loss of mobility, or loss of feeling.
• Thumbs might experience pain at the base.
• Feet and toes might also experience symptoms such as numbness or tingling, stiffness, or a burning sensation.

Outward Signs of MSDs

Outward signs of MSDs may include:

• Visible swelling or inflammation of joints, such as shoulders, elbows, wrists, or knees.
• Vigorous shaking of the hands, as though trying to regain circulation.
• Massaging of hands, wrists, and arms, as though to relieve pain or regain circulation.
• Cradling of arms when standing or sitting in a meeting, as if trying to find a less painful position.
• Limping or wincing with pain when walking.
• Moving with stiff back, or difficulty bending over to pick up something, or placing hands on lower back as if trying to support it.

Common MSDs

A list of common MSDs is presented here and on the next slide. This is not a complete list, but it includes those that are most frequently experienced.

• Carpal tunnel syndrome is the compression of the median nerve where it passes through the wrist and into the hand. It sometimes develops when someone types with his or her wrist bent and resting on a table.
• Low back pain is often the result of injury to muscles from improper bending and lifting heavy objects, or from improper posture when sitting or standing.
• Eyestrain is usually a feeling of tiredness in the eyes, or some eye discomfort after a long period of work, that is not due to a specific injury.
• Tendinitis is inflammation of a tendon that happens when a muscle or tendon is repeatedly tensed. It often results from overuse of the wrist, shoulder, or elbow.
• Trigger finger is a tendon disorder that occurs in the flexing tendon of the finger. The finger has snapping or jerking movements when you attempt to move it. This type of MSD is associated with using tools that have handles with hard or sharp edges.

Common MSDs (cont.)

Additional common MSDs include:

• De Quervain’s disease is inflammation of the tendon sheath of the thumb caused by excessive friction between two thumb tendons. This is usually the result of twisting and forceful gripping motions.
• Carpet layer’s knee is a variety of symptoms that are caused by frequent kneeling on a hard surface and using a knee kicker for stretching wall-to-wall carpet. Symptoms include bursitis of the knee, fluid buildup, and skin infections.
• Rotator cuff tendinitis occurs from working with the hands above the head repeatedly over a long period of time.
• A herniated disk is a bulge in one of the disks that cushion the backbone. The most common symptom is sciatica, a sharp shooting pain down the back of the leg. This is caused by pressure on the spinal nerve, which can occur from repeated bending, twisting, or carrying loads at arm’s length. Other symptoms include weakness in one leg or burning pain in the back.
• Finally, Hand-arm vibration syndrome occurs when the blood vessels of the hand are damaged from repeated exposure to vibration for long periods of time. The skin and muscles of the hand do not get the blood or oxygen they need, and experience numbness, tingling, loss of color, loss of sensation in the hand, or loss of control of the hand.

Act on the Signs of MSD

You should act immediately on any sign of MSDs:

• Report the problem immediately to your supervisor.
• Seek medical attention.
• Remember that early treatment and intervention often can prevent the condition from getting worse, or becoming permanent.

What Do You Think?

• This employee works in a warehouse setting and lifts various objects throughout the day.
• He often experiences pain—which can range from minor to severe— while on the job and at home—even when he is not lifting.
• What do you think is causing this employee’s pain?
• What do you think can be done to improve this situation?

What is Causing the Pain?

Here are some things that might be causing this employee’s pain. Of course, since we don’t know about the history surrounding the pain, these are only the most likely causes. The employee would need a doctor’s diagnosis to be completely sure.

• The pain could be a repetitive injury from lifting heavy objects throughout the day over a long period of time.
• Another possibility is that the employee has injured his back as a result of twisting while lifting. The back should always maintain its natural curves while lifting—and you should never twist.
• Poor lifting techniques, such as bending at the waist to lift, can also cause immediate injury or can damage the back over time.
• Lifting above the shoulders is another possibility. Doing this puts added strain on your back.
• This pain could be due to an injury caused by one specific event—such as the employee trying to lift an object that was too heavy or awkward.
• Finally, this pain could be caused by poor muscle conditioning— meaning if the employee is out of shape and does not stretch and exercise properly, then tries to lift objects at work, the muscles are more likely to be injured easily.

What Can Be Done?

To prevent an injury from occurring:

• Use lifting aids whenever possible, especially when lifting repetitively or lifting heavy objects.
• Never twist your back while lifting—instead, move your feet so that your trunk stays straight, or rearrange your work area so that twisting is not necessary while lifting.
• Always lift with your legs, not your back. Squat down, bring the load close to your body, and lift with your legs.
• If you need to lift something above your shoulders, use a stool or stepladder. Remember never to use the top two steps or rungs.
• Don’t try to be a hero—if an object is too heavy for you to lift, get help from either a mechanical lifting aid or from another employee.
• Finally, remember to keep your back in top shape by exercising and keeping your weight down. For example, doing sit-ups regularly will help strengthen both your stomach and back muscles, both of which help in the lifting process. This will help prevent injuries from occurring.

Check Your Knowledge

Here is a list of symptoms—do you know which are related to musculoskeletal disorders?

-Tingling [Yes]

-Racing Heart [No]

-Pain [Yes]

-Numbness [Yes]

-Loss of muscle function [Yes]

-Dizziness [No]

-Excessive Cough [No]

-Stiffness [Yes]

-Swelling of joints [Yes]

MSDs – Any Questions?

• Do you understand what MSDs are and the signs and symptoms of MSDs?

Now it is time to ask yourself if you understand the material presented so far.

It is important that you understand the signs and symptoms of MSDs.

Risk Factors That Lead to MSDs

Now let’s turn our attention to some of the risk factors that lead to MSDs in the workplace. We’ll discuss these risk factors in the next few slides, but generally, the most common risk factors are:

• Repetitive motions;
• Forceful exertions;
• Awkward postures;
• Pressure points or contact stress;
• Vibrations; and
• Using tools that are not ergonomically designed, such as screwdrivers with narrow handles or pliers that require a wide grip.

Risk Factor – Repetitive Motion

Repetitive motion is a common risk factor for MSDs.

• Stress on the muscles and tendons result from doing the same motion over and over.
• Certain contributing factors determine whether repetition is likely to cause MSDs; these include:

– The duration and speed of the motion—how often and how quickly it is repeated;

– The number of muscles involved in the motion; and

– The required force to perform the movement.

• Raising and lowering the arm over and over again with the same degree of force, as shown in the picture, is an example of a risk factor.

Forceful Exertions

Forceful exertions that are required by certain jobs are a major risk factor for MSDs.

• Inflammation of the tendons, nerves, and joints is frequently the result of forceful exertions.
• Contributing factors to the risk of MSDs from forceful exertions include:

– The type of grip required – for example, does using force require a natural grip or an awkward grip;

– The weight of the object;

– Body posture required with the exertion; and

– The specific type and duration of the task.

Awkward Postures

Awkward postures are sometimes a risk factor for MSDs.

• Stress on muscles and tendons can result from awkward postures. This can lead to back pain, tendinitis, and damage to joints by forcing them out of their natural positions.
• Contributing factors to awkward posture as an MSD risk include:

– Reaching overhead;

– The force the body must maintain in order to hold the awkward position; and

– Holding fixed positions, such as bending and twisting, known as static loading.

• Lifting an object while twisting, reaching, or turning is an example of an awkward motion that could mean a risk for MSDs.

Contact Stress

“Contact stress” is defined as continuous contact or rubbing between hard or sharp objects or surfaces and sensitive body tissues, such as the soft tissue of the fingers, palms, thighs, and feet.

• Pressing against or grabbing a hard object puts pressure on the nerves, tendons, and blood vessels, and can inhibit their function.
• Contributing factors for contact stress include:

– Repetition—how often the stress must be repeated;

– The duration of the contact; and

– The strength of grip required.

Vibration

Vibration for long periods of time can be a major risk factor for MSDs such as hand-arm vibration syndrome.

• Vibration affects the tendons, muscles, joints, and nerves.
• Contributing factors that can lead to MSDs caused by vibrations include:

– Prolonged grip on a vibrating object;

– Restrictions on the blood supply to the hands and fingers;

– Using tools that do not have vibration dampening devices; and

– Poor power tool maintenance, causing them to vibrate more than they should.

• Prolonged use of a grinder is an example of vibration as an MSD risk factor. Other examples involving power tools include prolonged use of jackhammers, sanders, saws, chippers, routers, and drills.

MSDs Related To Risk Factors

Here are some of the common types of MSDs related to the risk factors we’ve described. Note that they often result from repetitive motion, awkward posture, use of force, contact stress, or use of vibrating tools. For example:

• De Quervain’s disease can be the result of using a forceful grip;
• Trigger finger can be the result of contact stress;
• Rotator cuff syndrome can be caused by repetitive motions;
• Thoracic outlet syndrome may be due to awkward posture; and
• Hand-arm vibration syndrome can result from prolonged vibration.

Can You Identify The Risk Factors?

What’s wrong here? By looking at these photos, see if you can identify potential risk factors for MSDs.

This man was lifting wood stock off shelving and placing it on a raised forklift pallet when he tore a tendon near his shoulder and arm joint. He said he didn’t do anything out of the ordinary. What do you think went wrong? What were the risk factors?

Can You Identify The Risk Factors? (cont.)

The risk factors include:

• Repetitive motion
• Lifting or reaching with an awkward posture or excessive weight, and working with the arms raised.

In addition to the torn tendon, some other potential MSDs related to this activity include:

• Tendinitis and
• Back pain

Is it possible that this man might have experienced MSD symptoms before the injury occurred? Yes. If this task was a normal part of his job, he might have already been experiencing painful joints, back and shoulder stiffness, or swelling and inflammation.

MSD Risk Factors – Any Questions?

• Do you understand MSD risk factors that have been discussed in the previous slides? Do you feel you know what you need to know about the hazards that can cause MSDs?

It is time to ask yourself if you understand the material presented so far.

It is important that you understand MSD risk factors and hazards.

Ergonomics Management

The next few slides will discuss ways to manage, prevent, and control MSD hazards.

Ergonomics management is the first step, and it includes the following:

• A job assessment, or job hazard analysis, which is conducted for the various workstations and tasks in the facility, to identify possible MSD hazards.
• An MSD reporting and response system, which is designed and included in our ergonomics program.
• A designated ergonomics coordinator, who is involved in all aspects of our program to control and prevent MSDs through ergonomics.
• Employee training to teach employees about ergonomics and MSD prevention.
• Finally, our ergonomics program encourages employee participation and reporting of MSDs.

Identifying and Controlling MSD Hazards

Identifying and controlling MSD hazards is the next step that follows in our ergonomics management program.

• As noted on the previous slide, we identify MSD hazards and the degree of risk through a job hazard analysis.
• We devise a control strategy, with your input, for those jobs that have MSD risk factors and a high degree of risk. Your involvement in designing the control strategy is important because you know the hazards and may already have experienced MSD signs and symptoms. Your ideas are extremely valuable.
• We then implement the control measures to reduce the hazards.
• Finally, specific training is provided for affected employees and supervisors once control measures are in place so that everyone better understands how to prevent MSDs.

Control Methods

There are a number of important control methods for MSD hazards.

• Engineering controls are the preferred approach. Examples of engineering controls include designing the workstation layout ergonomically and using ergonomically designed tools.
• Work practice controls are changes in the way employees perform the physical activities of a job to reduce MSD hazards. One work practice control is to use neutral postures to perform tasks—for instance, keeping wrists straight or lifting close to the body, rather than working with wrists bent or lifting with arms extended. Another example would be to use two-person lift teams.
• Administrative controls include rescheduling of job assignments in ways that may reduce the frequency or duration of exposure to MSD hazards. Examples of administrative controls include employee rotation; assigning alternative tasks; changing the pace of the work; and job task enlargement, which means requiring a wider variety of tasks and motions rather than the same motion or activity over and over again for long periods of time.
• A final control method is personal protective equipment, or PPE, that provides a protective barrier between the worker and the MSD hazard. Examples of PPE include vibration-reduction gloves or knee pads for carpet layers.

How to Protect Yourself

There are many ways to protect yourself against MSDs.

• Change positions often and take stretch breaks in order to reduce your exposure to excessive repetitive motions. Another idea is to switch to other tasks that require the use of different muscles.
• Maintain a neutral posture whenever possible, and avoid working in an awkward posture whenever you can. Stand with your back straight, avoid bending forward or stooping, limit squatting and kneeling, keep your head straight and face forward, and avoid raising or hunching your shoulders. Always use proper lifting techniques and posture.
• Eliminate or reduce MSD risk factors by evaluating your job for possible risk factors. Inform your supervisor about these risk factors and work to make changes that will help reduce or eliminate them.
• Use material-handling aids, such as hand trucks, whenever possible, to reduce your need to apply force to a task, such as heavy lifting.
• Finally, report any MSD symptoms you may have to your supervisor.

MSD Prevention and Control – Any Questions?

• Do you think you understand what you need to know about MSD prevention and control?

It is important that you understand how to prevent and control MSDs.

Key Points To Remember!

The key points to remember about this training session on ergonomics are:

• First, learn how to recognize MSD signs and symptoms before they lead to serious health problems.
• Next, learn to recognize and understand MSD hazards, such as repetitive motions, awkward postures, use of force, and other hazards.
• Then, take the steps we’ve discussed in this session to control MSD hazards in your work area.
• Finally, participate in our ergonomics program, and become an active part of our program to prevent and control MSDs.

This concludes this training session on ergonomics in the industrial workplace.