1. Ergonomics 5. 3. 1. 7.
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15. 8. 6. 4.
INSTRUCTOR’S NOTES:
This presentation is designed to assist trainers conducting OSHA 10-hour General Industry outreach training for youth workers. Since youth workers are the target audience, this presentation may cover hazard identification, avoidance, and control – not standards. No attempt has been made to treat the topic exhaustively. It is essential that trainers tailor their presentations to the needs and understanding of their audience.
This presentation is not a substitute for any of the provisions of the Occupational Safety and Health Act of 1970 or for any standards issued by the U.S. Department of Labor. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. Department of Labor.

2. What is Ergonomics
Ergonomics is the science of adjusting environments, tasks, or procedures to fit the individual.
INSTRUCTOR’S NOTES:
Ergonomics is the science of adjusting environments, tasks, or procedures to fit the individual. Changing tasks, work stations, tools, and equipment so that they fit better helps people work more effectively, puts less physical strain on the body, and reduces the risk of developing a disabling physical disorder.
When work environments or tasks are not ergonomically designed, a hazard can be created.

3. Musculoskeletal Disorders
Improper ergonomics can result is your developing a Musculoskeletal Disorder(MSD). MSDs can affect your:
Muscles
Tendons
Nerves
Joints
Ligaments
Cartilage
Nervous system
INSTRUCTOR’S NOTES:
Poor ergonomics can result in many different types of injuries. One category of injuries is musculoskeletal disorders.
Musculoskeletal Disorders (MSDs) are injuries or illnesses that can affect:
muscles
tendons
nerves
joints
ligaments
cartilage and
nervous system
Workers who must repeat the same motion throughout their workday, who must do their work in an awkward position, who must use a great deal of force to perform their jobs, who must repeatedly lift heavy objects or who face a combination of these risk factors are most likely to develop MSDs. The level of risk depends on how long a worker is exposed to these conditions, how often they are exposed, and the level of exposure.

4. Musculoskeletal Disorders
MSDs can impact almost any part of your body, including:
Upper torso (back, neck, and shoulders)
Upper extremities (arms, wrists, and hands)
Lower extremities (legs and feet)
INSTRUCTOR’S NOTES:
MSDs can impact almost any part of your body:
Upper torso, including the back, neck, and shoulders
Upper extremities, including the arms, wrists, and hands
Lower extremities, including the legs and feet

5. Musculoskeletal Disorders
Signs and symptoms of MSDs include:
Pain, numbness, and tingling
Cramping
Swelling or stiffness of joints
Reduced range of motion
INSTRUCTOR’S NOTES:
These are symptoms that could indicate a worker is either at risk or developing an MSD. The employee should inform his/her doctor as well as his/her employer. Some specific MSDs students may have heard about include tendonitis and carpal tunnel syndrome. It is important to report signs and symptoms as early as possible to prevent serious injury or permanent damage.

6. Musculoskeletal Disorders
Common types of MSDs include:
Cumulative trauma disorders
Repetitive stress injuries
Repetitive motion injuries
INSTRUCTOR’S NOTES:
These injuries develop and become worse over a period of time from repeated stress to your body.

7. MSD Risk Factors
Factors that contribute to the development of MSDs include:
Awkward postures
Repetitive motions
Forceful exertions
Contact stress
Vibration
INSTRUCTOR’S NOTES:
Contributing factors are aspects of work tasks which can lead to fatigue, musculoskeletal disorder (MSD) symptoms and injuries, or other
types of problems. These factors may be present in one or more of the tasks employees must perform to accomplish their jobs. The contributing
factors employees should be aware of include:
• Awkward postures
• Repetitive motions
• Forceful exertions
• Pressure points (e.g., local contact stress)
• Vibration
There are also environmental factors associated with the workplace which can cause problems. Extreme high temperatures can increase the
rate at which the body will fatigue. Alternatively, exposure of the hands and feet to cold temperatures can decrease blood flow, muscle strength,
and manual dexterity. These conditions can also cause excessive grip force to be applied to tool handles or objects. In addition, the lighting in a workplace may be too dark or too bright for the work task. This may result in employees assuming awkward postures to accomplish work tasks and a loss of product quality.
Workers should also be aware of the amount of time in a workday they spend performing physically demanding or repetitive tasks
(i.e., the duration of tasks). Both the total time per work shift and the length of uninterrupted periods of work can be significant in contributing
to problems.

8. Awkward Posture
Posture is important. Awkward postures are a risk factor for MSDs.
Awkward postures include bending, twisting, and working with your hands above your head or your elbows above your shoulders.
INSTRUCTOR’S NOTES:
Awkward postures are unsupported positions that can stretch a worker’s physical limitations. These postures can compress nerves and irritate tendons.
Posture affects which muscle groups are active during physical activity. Awkward postures can make work tasks more physically demanding, by
increasing the exertion required from smaller muscle groups, and preventing the stronger, larger muscle groups from working at maximum efficiencies. The increased exertion from the weaker, smaller muscle groups impairs blood flow and increases the rate of fatigue.
Awkward postures typically include repeated or prolonged reaching, twisting, bending, working overhead, kneeling, squatting, and holding
fixed positions or pinch grips. They may affect various areas of the body such as the hands, wrists, arms, shoulders, neck, back, and knees. The
effects of awkward postures are worse if work tasks also involve repetitive motions or forceful exertions. Awkward postures may be caused by using poorly designed or arranged workstations, tools, and equipment and poor work practices.

9. Repetitive Movements
Some jobs may require you to perform the same movements over and over again.
Repetitive movements can irritate your tendons and increase pressure on your nerves.
INSTRUCTOR’S NOTES:
Some jobs may require workers to perform the same movements repeatedly. These repetitive movements can irritate tendons and increase pressure on nerves. Also, these types of movements may cause tissues and muscles to be overused if adequate time is not allowed for recovery. Highly repetitive tasks often involve the use of only a few muscles or body parts while the rest of the body is unaffected.
The amount of repetition can be affected by the pace of work, the recovery time provided (i.e., number and length of muscle relaxation breaks), and the amount of variety in work tasks. The pace of work may be controlled by the employee performing the task, machines, other employees, or administrative procedures. Examples of jobs involving machine-controlled pace include working on assembly, packaging, or quality-control lines.

10. Force Force is the amount of muscular effort used to perform work.
Exerting large amounts of force can result in fatigue and physical damage to your body.
INSTRUCTOR’S NOTES:
The amount of force exerted when moving or handling materials, tools, or objects depends on a combination of factors, including:
Load shape, weight, dimensions, and bulkiness
• Grip type, position, and friction characteristics
• Amount of effort required to start and stop the load when moving it (i.e., how physically demanding it is to accelerate or decelerate the load)
• Length of time continuous force is applied by the muscles (e.g., the amount of time the load or object is held, carried, or handled without a
muscle relaxation break)
• Number of times the load is handled per hour or work shift
• Amount of associated vibration
• Body posture used
• Resistance associated with moving the load (e.g., over rough flooring or with poorly maintained equipment)
• Duration of the task over the work shift
• Environmental temperature
• Amount of rotational force (e.g., torque from tools or equipment)

11. Contact Stress
Contact stress occurs internally when a tendon, nerve or blood vessel is stretched or bent around a bone or tendon. External contact stress occurs when a part of your body rubs against a sharp or hard object such as the edge of a desk or table.
INSTRUCTOR’S NOTES:
Contact stress can occur either internally or externally. Internal stress occurs when a tendon, nerve, or blood vessel is stretched or bent around a bone or tendon. External contact stress occurs when part of the body rubs against a sharp or hard object such as the edge of a desk or table. Nerves may be irritated or blood vessels constricted as a result. Certain areas of the body are more susceptible because nerves, tendons, and blood vessels are close to the skin and underlying bones. These areas include the sides of the fingers, palms, wrists and forearms, elbows, and the knees.

12. Vibration Excessive vibration can: Decrease blood flow Damage nerves
Contribute to muscle fatigue
INSTRUCTOR’S NOTES:
Injuries can occur from excessive vibration. Excessive vibration can decrease blood flow, damage nerves, and contribute to muscle fatigue. Vibration exposure is of concern when it is continuous or of very high intensity. Using vibrating tools such as sanders, grinders, chippers, routers,
impact guns, drills, chain saws, and circular saws can cause exposure to hand-arm vibration. Tools that are not properly maintained or are inappropriate for the task may increase the amount of hand-arm vibration. These exposures may result in fatigue, pain, numbness, tingling, increased sensitivity to cold, and decreased sensitivity to touch in the fingers, hands, and arms.

13. Personal Risk Factors
There are also personal risk factors that can contribute to the development of MSDs. These personal risk factors include:
Physical condition
Psychological stressors
Gender
Age
Body size
Medical condition
INSTRUCTOR’S NOTES:
Other risk factors are personal risk factors that are unique to each individual. They may include:
Physical condition
Psychological stressors
Gender
Age
Body size, and
Medical condition
These personal risk factors may make certain types of work more difficult and lead to an increased risk of injury.
Various medical conditions may predispose individuals to MSDs or make the disorders worse. Examples include:
• Arthritis
• Pregnancy
• Bone and muscle conditions
• Previous trauma
• Contraceptive use
• Thyroid problems
• Diabetes mellitus
In addition, psychosocial factors may have an impact on MSDs. These factors include:
• Level of stress
• Level of job security and satisfaction
• Amount of autonomy on the job (e.g., degree of control over the arrangement of work areas or the pace of work)

14. Good Posture
A good working position is an upright sitting posture, in which the torso and neck are approximately vertical, the thighs are approximately horizontal, and the lower legs are vertical.
INSTRUCTOR’S NOTES:
Working with the body in a neutral position reduces stress and strain on the muscles, tendons, and skeletal system and reduces your risk of developing a musculoskeletal disorder (MSD).
Upright Sitting Posture.
Your torso and neck are approximately vertical and in-line, the thighs are approximately horizontal, and the lower legs are vertical.

15. Good Posture
Another good working position is a declined sitting posture with the buttocks higher than the knees and the angle between the thighs and the torso is greater than 90 degrees.
INSTRUCTOR’S NOTES:
Declined Sitting Posture
Your thighs are inclined with the buttocks higher than the knee and the angle between the thighs and the torso is greater than 90 degrees. The torso is vertical or slightly reclined and the legs are vertical.

16. Good Posture
In the reclined sitting posture, the torso and neck are straight and recline between 105 and 120 degrees from the thighs.
INSTRUCTOR’S NOTES:
Reclined Sitting Posture
Your torso and neck are straight and recline between 105 and 120 degrees from the thighs.

17. Good Posture
An upright standing posture is a good working position. In this position the legs, torso and neck are approximately in-line and vertical.
INSTRUCTOR’S NOTES:
Standing Posture
Your legs, torso, neck, and head are approximately in-line and vertical. The user may also elevate one foot on a rest while in this posture.

18. Lifting
The most common work-related medical problem is lower back pain.
This is often a result of poor lifting techniques. If you have to do any lifting:
Think before you lift!
Test the load and ask yourself – “Can I lift it safely?” If not, get help!
Make sure there is nothing in your path that could cause you to fall.
INSTRUCTOR’S NOTES:
The most common work-related medical problem is lower back pain. It affects more than 20 million Americans and is the leading cause of disability among people ages Often, lower back pain is a result of poor lifting techniques.
To StartSafe and StaySafe while lifting do the following:
Think before you lift.
Ask yourself, “Can I lift this safely?” If you can’t, get help or don’t lift the object at all.
Before you start to move an something, make sure there is nothing in your path that could cause a fall and that you have a place to safely set down the object.

19. Lifting Lifting safely means: Squat to bend at the knees
Keep your head up
Get a good grip with both hands and hold it close to the body
Lift smoothly using your legs
Do not use your back
Turn with your feet, don’t twist your back
INSTRUCTOR’S NOTES
Work with the students to practice safe lifting techniques.

20. Ergonomics In Action Understanding and practicing good ergonomics can:
Make your job less stressful on your body
Increase your safety and productivity
Create a more comfortable environment
Prevent injuries and illnesses
INSTRUCTOR’S NOTES:
By understanding and practicing good ergonomics, you can:
make your job less physically stressful
increase your safety and productivity
create a more comfortable environment
prevent injuries and illnesses
Additionally, ergonomics can be useful everywhere like at home, at school, in your car - helping you stay healthy and safe.

21. Summary
Here are some actions that will help you StartSafe and StaySafe when it comes to ergonomics:
Adjust your tasks or environment to fit you
Reduce risk factors
Avoid unnecessary movements
Always practice safe lifting
Use the tools that are right for you
Perform light stretching and other exercises
before and during work
INSTRUCTOR’S NOTES
Challenge the students to keep an eye out for and correct ergonomic hazards in their school, workplace and home.