2. What is Ergonomics?
Ergonomics: The science of fitting jobs to people.
Encompasses the body of knowledge about
physical abilities and limitations as well as other
human characteristics relevant to job design.
Ergonomic design: The application of this body of
knowledge to the design of the workplace (tasks,
equipment, environment) for safe and efficient
worker use.
Good ergonomic design: Makes the most efficient
use of worker capabilities while ensuring job
demands do not exceed those capabilities.
2PPT-010-02
3. Ergonomic Hazards
Do not ignore signs, symptoms, and hazards!
Make recommendations for control of hazards
to your supervisor.
3PPT-010-02
Ergonomic Lifting
Device
6. Musculoskeletal Disorders
MSD’s do not include injuries caused by slips,
trips, falls, or other similar accidents.
MSD’s can differ in severity from mild periodic
symptoms to severe chronic and debilitating
conditions.
6PPT-010-02
7. MSDs – Signs & Symptoms
• Aching
• Burning
• Cramping
• Loss of Color
• Numbness
7PPT-010-02
9. MSDs-Carpal Tunnel
• Carpal Tunnel – a tunnel
in the wrist through which
the median nerve and
nine digital flexor tendons
pass.
• Formed by the wrist bones
and a dense trans-carpal
ligament.
• Continued and repetitive
pressure on the median
nerve in the carpal tunnel
can cause Carpal Tunnel
Syndrome (CTS).
9PPT-010-02
10. MSDs-How CTS Develops
1. Swelling or thickening of the tendons.
2. The tunnel begins to close.
3. This exerts pressure on the median nerve.
4. Feel pain/discomfort.
10PPT-010-02
11. MSDs-Prevention of CTS
• If you do the same tasks with your hands over
and over, try not to bend, extend, or twist your
hands for long periods.
• Don’t work with your arms too close or too far
from your body.
• Don’t rest your wrists on hard surfaces for long
periods.
• Switch hands during work tasks if possible.
11PPT-010-02
12. MSDs-Prevention of CTS
• Take regular breaks from repeated hand
movements to give your hands and wrists time
to rest.
• Don’t sit or stand in the same position all day.
• Adjust your chair so your forearms are level with
your keyboard and you don’t flex your wrists to
type.
12PPT-010-02
13. MSDs-Back Injuries
Heavy lifting from above the
shoulders.
Heavy lifting from below the
knees.
Twisting while lifting/carrying.
Bending over at the waist.
→ → → → → → → → →
Carrying objects to one side.
13PPT-010-02
14. MSDs-Protect Your Back
Lifting
• Avoid bending at the
waist.
• Squat down with your
back straight & knees
bent.
• Grasp the object.
• Bring it close to your
body.
• Slowly rise.
• Let your thigh muscles
do the lifting.
14PPT-010-02
15. MSDs-Protect Your Back
Standing
• Shift your weight slightly.
• Use proper footwear with cushioned insoles.
• Avoid high heels.
• Proper posture when standing =
→ Shoulders not rolled forward
→ Stomach area pulled in
→ Small of the back straight
→ Hips not tilted
15PPT-010-02
17. MSDs-Protect Your Back
Sitting
• Use an adjustable chair with
lower back support.
• Keep knees in line with the
hip joints or slightly lower.
• Sit with your lower back
firmly against the chair
back support.
• Shift elevation of your legs
during prolonged sitting.
• Avoid crossing your legs.
17PPT-010-02
Any ergonomic issues?
If prolonged sitting, back
will hurt due to no support.
18. MSDs-Protect Your Back
Lying down
• Lie on your side with your knees slightly bent.
• Use a pillow to elevate your head keeping it in
line with your back.
• If you sleep on your back, place a pillow under
your knees to relieve lower back stress and
promote proper alignment.
18PPT-010-02
Awkward position-could cause
ergonomic issues if in the position for
extended period
19. MSDs-Joint Disorders
• Joints involve many structures, including
tendons, muscles, nerves, and bones.
• Inflammation may be caused by joint
damage or repetitive heavy use.
• With inadequate repair, cartilage thinning
may lead to osteoarthritis.
19PPT-010-02
20. MSDs-Joint Disorders
• Work tasks that may be associated with lower-
extremity joint loading: Repetitive/prolonged
stair or ladder climbing, kneeling, squatting,
standing, carrying heavy loads, jumping.
• Mechanical stresses associated with certain tasks
can cause degenerative joint disease.
• Degenerative joint disease can occur even after
relatively low loads on joints if the forces are
applied impulsively and repetitively.
20PPT-010-02
21. MSD Risk Factors
Awkward Postures
Two Types:
Static = non-moving
Dynamic = body in motion
Stress increases if any weight is
added by tools or other objects.
Factors include:
• Time
• Repetition
• Body condition
• Health
• Range of motion
21PPT-010-02
22. MSD Risk Factors-Avoid:
• Bent wrists
• Twisting at the waist
• Rolled shoulders
• Leaning forward
• Bending at the waist
22PPT-010-02
24. MSD Risk Factors
Force & Exertion = Forceful exertions place higher
loads on the muscles, tendons, ligaments, and
joints
Factors:
• Weight of load or tool
• Bulkiness of load or tool
• Posture during
• Speed of movement
24PPT-010-02
25. MSD Risk Factors-Prevention
Lifting
• Place heavier material above the knees and
below shoulder height
• Use team lifting
• Use mechanical devices such as tool supports,
platforms lifts, barrel lifts, air lifts, and hoists
Moving
• Lower required force by using carts, trolleys,
pallet jacks, conveyors and tracked lifts
25PPT-010-02
26. MSD Risk Factors
Reduce Force & Exertion by Reducing:
• Weight of the object
• Weight of the container
• Load in the container
• Size of the container
• Quantity per container
26PPT-010-02
28. MSD Risks-Pressure
Hazards = Damage to Nerves & Blood Vessels
• External Compression – sharp edges concentrate
forces on a small area of the anatomy resulting in
high, localized pressure.
• Internal Compression – nerves, vessels, and
other soft tissues may be internally compressed
under conditions of:
◦ High-force exertions
◦ Awkward postures
◦ Static postures
◦ Swelling of injured tissue
◦ High velocity or acceleration of movement
28PPT-010-02
29. MSD Risks-Pressure
Tools & Work Practice
Hazards:
• Tools with short
handles (e.g. pliers
and paint scrapers).
• Leaning the side of
the elbow on a hard
surface.
• Carrying heavy loads
on the shoulder.
• Long periods of
kneeling.
29PPT-010-02
31. MSD Risks-Cold
Cold environments compromise
muscle efficiency.
Possible vascular and
neurological damage.
Workers with cold-desensitized
fingers may grasp loads with
more force than necessary:
exposes muscles, soft tissues,
and joints to increased force.
Alcohol, nicotine, caffeine, and
some medication increases MSD
risks from cold temperatures.
31PPT-010-02
33. MSD Risks-Noise
Hazards of too much or not
enough light:
• Awkward postures
• Muscle fatigue
• Eye strain
• Mental fatigue
33PPT-010-02
34. Life Factors - Exercise
Proper exercise means:
• Improved health
• Stronger body
• Improved endurance
• Reduced stress
• Better range of motion
34PPT-010-02
35. Life Factors-Smoking
• Restricts blood vessels
• Carbon monoxide in blood
• Longer recovery from injury
• Increased injuries from vibration
• Increased injuries from cold
• Poor general health
35PPT-010-02
36. Life Factors-Medication
Medication has the
potential to increase the
risk of MSD’s if it:
• Lowers or raises normal
blood pressure
• Changes sense of
balance
• Masks pain
• Relaxes muscles
• Affects blood circulation
• Affects eyesight
36PPT-010-02
38. Ergonomic Controls-Engineering
Engineering controls:
• Preferred method for controlling hazards.
• Make physical changes to tasks.
• Act on the source of the hazard.
• Control employee exposure.
• Do not require “self-protective” action.
38PPT-010-02
40. Ergonomic Controls-Administrative
Administrative controls = procedures and
methods that significantly reduce daily exposure
to WMSD hazards by altering the way in which
work is performed.
Examples:
• Employee Rotation
• Job Task Enlargement
• Adjustment of work place
• Redesign of work methods
• Alternative Tasks
• Rest Breaks
40PPT-010-02
41. Work Practice Controls
Behavior based controls that change the manner in which a job
is performed.
Procedures for safe and proper work that are understood and
followed by managers, supervisors, and employees.
Examples of work practice controls for WMSD hazards include:
Safe work techniques and procedures
Conditioning period for new or reassigned employees
Training in the recognition of ergonomic hazards
Training in work techniques that reduce MSD hazard
41PPT-010-02
42. Sitting Position
• Use a straight chair with support for your lower
spinal curve.
• Use a small cushion or rolled up towel behind
your back to maintain the proper curve.
• Check the seat’s height.
• Adjust your seat so that your knees are equal
with or slightly lower than your hips.
• If the seat’s height is not adjustable use a
footrest if necessary.
• Keep your feet flat; avoid crossing your legs.
• Keep your ankles and elbows at right angles.
42PPT-010-02
43. Sitting Posture
• Sit close to your desk so you don’t have to bend
forward.
• If you do bend, bend from your hips.
• Position your work or chair so you can look
forward rather than down.
• Use a document holder or move your computer
screen so the top of it is at eye level.
• Shift your position frequently to prevent strain.
• Take a break or do stretching exercises.
43PPT-010-02
45. Prevent, Prevent, Prevent
• The bottom line: prevent accidents and injuries
from occurring!
• Ensuring your workstation is ergonomically
designed is one method to prevent injuries.
• All employees need to have a basic understanding
of ergonomics, and should report any ergonomic
hazards to their Supervisor immediately.
45PPT-010-02
46. Exercise-Knee Kiss
• Pull one leg to your chest, grasp with both hands
and hold for a count of five.
• Repeat with the opposite leg.
46PPT-010-02
47. Exercise-Windmill
• Place your feet apart on the floor.
• Bend over and touch your right
hand to your left foot, with your
left arm up.
• Repeat with opposite arm.
47PPT-010-02
48. Exercise-Back Relaxer
• Bend down between your knees for as long as you
can.
• Return to upright position, straighten, and relax.
48PPT-010-02
49. Exercise-Pectoral Stretch
• Grasp your hands behind your neck and press
your elbows back as far as you can.
• Return to starting position, then drop your arms
and relax.
• Relax.
49PPT-010-02
50. Upper/Middle Back Stretch
• Raise your right arm and grasp it below the
elbow with your left hand.
• Gently pull your right elbow toward your left
shoulder as you feel the stretch.
• Hold for five seconds.
• Repeat for left side.
50PPT-010-02
51. Exercise-Side Stretch
• Interlace your fingers and lift your arms over your
head, keeping your elbows straight.
• Press your arms backward as far as you can.
• Slowly lean to the left, and then to the right until
you can feel the stretching.
51PPT-010-02
52. Exercise-Finger Stretch
• With palms down, spread your fingers apart as far
as you can.
• Hold for the count of five.
• Relax and then repeat.
52PPT-010-02
53. Exercise-Shoulder Roll
• Slowly roll your shoulders forward five times in a
circular motion using your full range of motion.
• Then roll your shoulders backward five times with
the same circular motion.
53PPT-010-02
54. Review
• Repetitive motion tasks can lead to Musculo-
Skeletal Disorders (MSD’s).
• Maintain correct posture while sitting, standing
and walking.
• Stretch to “limber up” muscles before and after
work.
• Take regular breaks.
54PPT-010-02
55. Review
• Exercise regularly.
• Ensure your workstation is set up ergonomically
correct for you.
• Ensure lighting in your work area is adequate.
• Report ergonomic hazards or symptoms to your
Supervisor.
55PPT-010-02
56. Contact Information
Health & Safety Training Specialists
1171 South Cameron Street, Room 324
Harrisburg, PA 17104-2501
(717) 772-1635
RA-LI-BWC-PATHS@pa.gov
56PPT-010-02
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Ergonomics can be defined as the study of workplace design; the study of how a workplace and the equipment used there can best be designed for comfort, efficiency, safety, and productivity.
It is also defined as the design of workplace or equipment: those factors or qualities in the design of something, especially a workplace or equipment used by people at work, that contribute to comfort, efficiency, safety, and ease of use.
Ergonomics: is the science of fitting jobs to people. It encompasses the body of knowledge about physical abilities and limitations as well as other human characteristics relevant to job design.
In Ergonomic hazard identification we look at existing conditions which can be corrected by environmental relationships. We also view the exertions by workers and movement to determine potential hazards.
Do not ignore signs, symptoms, and hazards!
Make recommendations for control of hazards to your supervisor.
Ergonomics looks at potential results of faulty systems and activities which may result in Musculoskeletal disorders. MSD’s are injuries or illnesses to soft body tissue such as:
Muscles
Nerves
Tendons
Ligaments
Joints
Cartilage
Spinal Discs
An improper match of a worker to their environment can disrupt the intended operation of the worker’s physical system.
All physical units are supposed to work in concert without resulting in negative impacts.
Ergonomic evaluations attempt to ensure his harmony through special provisions.
Musculoskeletal disorders do NOT include injuries caused by slips, trips, falls, or other similar accidents.
MSD’s can differ in severity from mild periodic symptoms to severe chronic and debilitating conditions.
Some of the signs and symptoms of MSD’s would include:
Aching
Burning
Cramping
Loss of Color
Numbness
Depending upon the cause of the MSD, such as repetition, turning, lifting or over-extending, further symptoms may be found as:
Pain
Swelling
Stiffness
Tingling
weakness
Carpal Tunnel is a tunnel in the wrist through which the median nerve and nine digital flexor tendons pass.
Formed by the wrist bones and a dense trans-carpal ligament.
Continued and repetitive pressure on the median nerve in the carpal tunnel can cause Carpal Tunnel Syndrome (CTS)
The progression of Carpal Tunnel Syndrome usually displays itself through:
1. Swelling or thickening of the tendons.
2. The tunnel begins to close.
3. This exerts pressure on the median nerve.
4. Feel pain/discomfort.
You may be able to prevent Carpal Tunnel Syndrome in a variety of ways.
If you do the same tasks with your hands over and over, try not to bend, extend, or twist your hands for long periods.
Don’t work with your arms too close or too far from your body.
Don’t rest your wrists on hard surfaces for long periods.
Switch hands during work tasks if possible.
CTS prevention also includes:
Take regular breaks from repeated hand movements to give your hands and wrists time to rest.
Don’t sit or stand in the same position all day.
Adjust your chair so your forearms are level with your keyboard and you don’t flex your wrists to type.
Common causes of back injuries include:
Heavy lifting from above the shoulders.
Heavy lifting from below the knees.
Twisting while lifting/carrying.
Bending over at the waist.
Carrying objects to one side.
During your normal duties, you must protect your back. When lifting:
Avoid bending at the waist.
Squat down with your back straight & knees bent.
Grasp the object.
Bring it close to your body.
Slowly rise.
Let your thigh muscles do the lifting.
Some jobs have a period of extended standing. If such is the case with your job:
Shift your weight slightly.
Use proper footwear with cushioned insoles.
Avoid high heels.
Assume proper posture when standing which would be:
→ Shoulders not rolled forward
→ Stomach area pulled in
→ Small of the back straight
→ Hips not tilted
This will more evenly distribute your weight and not cause strain on one particular body part.
Match the footwear to the job. Some footwear can increase body strain by not allowing weight to be transferred through your body to the ground. An example would be wearing high heels in shipping and receiving.
Not only would the weight transfer be destroyed, but your ability to lift and pivot as required by duties would be hazardous.
Wearing safety shoes may also be required where weights can be dropped on feet. There’s no protection from this if you’re wearing shower shoes.
Always protect your back!
If you are sitting for extended periods or if only for a short period,
→Use an adjustable chair with lower back support.
→Keep knees in line with the hip joints or slightly lower.
→Sit with your lower back firmly against the chair back support.
→Shift elevation of your legs during prolonged sitting.
→Avoid crossing your legs.
Additional back protection while lying down requires you to:
Lie on your side with your knees slightly bent.
Use a pillow to elevate your head keeping it in line with your back.
If you sleep on your back, place a pillow under your knees to relieve lower back stress and promote proper alignment.
Joint disorders may also occur.
►Joints involve many structures, including tendons, muscles, nerves, and bones.
►Inflammation may be caused by joint damage or repetitive heavy use.
►With inadequate repair, cartilage thinning may lead to osteoarthritis.
Joint disorders can result from various tasks.
►Work tasks that may be associated with lower-extremity joint loading. Repetitive/prolonged stair or ladder climbing, kneeling, squatting, standing, carrying heavy loads or jumping may also contribute.
►Mechanical stresses associated with certain tasks can cause degenerative joint disease.
►Degenerative joint disease can occur even after relatively low loads on joints if the forces are applied impulsively and repetitively.
MSD risk factors can be due to awkward positions of which there are two (2) types.
Static, which is a non-moving posture and
Dynamic, where the body is in motion
Stress increases if any weight is added by tools or other objects.
Factors taken in account include:
Time
Repetition
Body condition
Health
Range of motion
Some of the risk factors to avoid:
Bent wrists
Twisting at the waist
Rolled shoulders
Leaning forward
Bending at the waist
Avoid:
Winged elbows
Overreaching
Stepping backwards
Locking your knees
Forceful exertions place higher loads on the muscles, tendons, ligaments, and joints.
Factors accenting this exertion would include:
Weight of the load or tool
Bulkiness of the load or tool
Posture during listing or movement of the load, and
Speed of movement from one position to another.
Preventive methods can be applied to various routines.
Lifting
Place heavier material above the knees and below shoulder height
Use team lifting when required
Use mechanical lifting devices such as tool supports, platforms lifts, barrel lifts, air lifts, and hoists
Moving
Lower the required force by using carts, trolleys, pallet jacks, conveyors and tracked lifts
Reduce Force & Exertion by Reducing:
Weight of the object. Know when to get assistance or use a machine to help lifting.
Weight of the container.
Load in the container
Size of the container. Can also include shape. Is it too unwieldy or bulky?
Quantity per container. Can you reduce the amount of a material inside container to better lift it?
Lifting also requires you be able to grip the object for lifting, traveling with it and finally to its destination. Factors affecting grip include:
Weight
Slipperiness
Vibration
Grip type
Surface and grip area shape
Pressure, both external compression and internal compression can damage nerves and blood vessels.
External Compression – sharp edges concentrate forces on a small area of the anatomy resulting in
high, localized pressure.
Internal Compression – nerves, vessels, and other soft tissues may be internally compressed under conditions of:
High-force exertions
Awkward postures
Static postures
Swelling of injured tissue
High velocity or acceleration of movement
Pressure can also result from tools as well as work practices.
Tools with short handles (e.g. pliers and paint scrapers).
Leaning the side of the elbow on a hard surface.
Carrying heavy loads on the shoulder.
Long periods of kneeling.
We are seeing more ergonomic tools on the market.
Manufacturers and the buying public are taking more of an interest in such tools understanding the consequences of CTS and MSD.
Cold environments compromise muscle efficiency.
Vascular and neurological damage is possible.
Workers with cold-desensitized fingers may grasp loads with more force than necessary: exposes muscles, soft tissues, and joints to increased force.
Alcohol, nicotine, caffeine, and some medications increase MSD risks from cold temperatures.
The effects of noise on the worker can be a risk factor in MSD.
Increased muscle tension
Quicker onset of fatigue
Mental stress
Reduced concentration
Diverted attention
Slower recovery time
Lighting can be something provided in either extreme; too little or too much. Such may lead to:
Awkward postures
Muscle fatigue
Eye strain
Mental fatigue
Certain life factors can help limit or reduce MSD, one being proper exercise.
Proper exercise means:
• Improved health
• Stronger body
• Improved endurance
• Reduced stress
• Better range of motion
The effects of smoking contribute to MSD.
Smoking restricts blood vessels
Carbon monoxide in blood is increased
Longer recovery from injury is required
It can cause increased injuries from vibration
It can increase injuries from cold
Smoking can lead to poor general health
Medication has the potential to increase the risk of MSD’s if it:
Lowers or raises normal blood pressure
Changes your sense of balance
Masks pain
Relaxes muscles
Affects blood circulation
Affects eyesight
Engineering controls can aid in MSD reduction.
Engineering controls include changing, modifying or redesigning:
Workstations
Tools
Facilities
Equipment
Materials
Processes
Engineering controls:
Often a preferred method for controlling hazards.
Physical changes to tasks are made.
They act on the source of the hazard.
Employee exposure is controlled.
They do not require “self-protective” action.
Workstations can be created which better accommodate the physical needs of the worker.
Whether standing or sitting, workstation dimensions can be planned to reduce eye strain, reaching, lifting, repetition and rotational body movements.
Administrative controls are procedures and methods that significantly reduce daily exposure to WMSD hazards by altering the way in which work is performed.
Examples:
Employee Rotation
Job Task Enlargement
Adjustment of work place
Redesign of work methods
Alternative Tasks
Rest Breaks
Work Practice Controls are behavior based controls that change the manner in which a job is performed.
Procedures for safe and proper work that are understood and followed by managers, supervisors, and employees.
Examples of work practice controls for MSD hazards include:
Safe work techniques and procedures
Conditioning period for new or reassigned employees
Training in the recognition of ergonomic hazards
Training in work techniques that reduce MSD hazard
Most office staff are at work stations sitting most of the day. To reduce this condition from causing MSD, try the following:
Use a straight chair with support for your lower spinal curve.
Use a small cushion or rolled up towel behind the small of your back to maintain the proper curve.
Check the seat’s height.
Adjust your seat so your knees are equal with or slightly lower than your hips.
If the seat’s height is not adjustable use a footrest if necessary to elevate your feet.
Keep your feet flat; avoid crossing your legs.
Keep your ankles and elbows at right angles.
Sitting posture also includes:
Sit close to your desk so you don’t have to bend forward.
If you do bend, bend from your hips.
Position your work or chair so you can look forward rather than down.
Use a document holder or move your computer screen so the top of it is at eye level.
Shift your position frequently to prevent strain.
Take a break or do stretching exercises.
Have management obtain an Ergonomic Chair. The cost in comparison to CTS or workers’ comp costs will be minimal.
These are available in most office supply stores.
When it comes to discussing MSD and CTS, the main mission is Prevention
The bottom line: prevent accidents and injuries from occurring!
Ensure your workstation is ergonomically designed to prevent injuries.
Provide all employees with a basic understanding of ergonomics, and have them report any ergonomic hazards to their Supervisor immediately.
Exercises at the workplace can help relieve strain and pain.
The Knee Kiss is one such exercise you can do at your desk.
While seated, pull one leg to your chest, grasp with both hands and hold for a count of five.
Repeat with the opposite leg.
Exercise- Windmill
While seated, place your feet apart on the floor.
Bend over and touch your right hand to your left foot, with your left arm up.
Repeat with opposite arm.
Exercise - Back Relaxer
-While seated, bend down between your knees for as long as you can.
-Return to upright position, straighten, and relax.
Exercise – Pectoral Stretch
- While seated, grasp your hands behind your neck and press your elbows back as far as you can.
- Return to starting position, then drop your arms and relax.
- Relax.
Exercise – Middle/Upper Back Stretch
- While seated, raise your right arm and grasp it below the elbow with your left hand.
- Gently pull your right elbow toward your left shoulder as you feel the stretch.
- Hold for five seconds.
- Repeat for left side.
Exercise – Side Stretch
While seated, interlace your fingers and lift your arms over your head, keeping your elbows straight.
Press your arms backward as far as you can.
Slowly lean to the left, and then to the right until you can feel the stretching.
Exercise – Finger Stretch
- With palms down, spread your fingers apart as far as you can.
- Hold for the count of five.
- Relax and then repeat.
Exercise – Shoulder Roll
-While seated, slowly roll your shoulders forward five times in a circular motion using your full range of motion.
-Then roll your shoulders backward five times with the same circular motion.
Remember:
Repetitive motion tasks can lead to Musculoskeletal Disorders (MSD’s).
Maintain correct posture while sitting, standing and walking.
Stretch to “limber up” muscles before and after work.
Take regular breaks.
Also remember:
Exercise regularly.
Ensure your workstation is set up ergonomically correct for you.
Ensure lighting in your work area is adequate.
Report ergonomic hazards or symptoms to your Supervisor.
