Safety class

profileص
osh_human_errors_.pptx

OSH 367 Human Factors

Introduction to Ergonomics and Posture and Movement

Chapters 1 and 2

Week Three:

Learning Goals

OSH 367 W4PPT1

2

Human-Machine Interaction Model

Humans and Machine interaction consists of 3 components:

The Human System

The Machine System

The Environment that surrounds them both

OSH 367 W4PPT1

3

Immediate Causes:

Behavior

Machines

Environmental Factors

Human Machine Interaction Model

Human System: Sensory Components

This is how humans detect information from the environment around them Ie.. Seeing, hearing, touching, smelling)….. Interaction with machines

OSH 367 W4PPT1

4

Human

Machine

Human Machine Interaction Model

Human Component: Cognitive Component

How human process information and formulate plans for action and signal the next component Ie. Human skeletal component to move… How you process information from the machine and respond

OSH 367 W4PPT1

5

Human

Machine

Human Machine Interaction Model

Machine system components mirrors the human side but with obvious differences.

The machine input component is how the machine receives information.

CPU receives the information and implements action based upon programming.

Machine display component relays to the human user information or feedback about the process

OSH 367 W4PPT1

6

Human-Machine Interaction Model

Environment component the conditions in which a job or job task is performed. Noise for example: Questions to consider:

Are there audible warning devices… Are they adequate? Should there be a visible warning device with the audible warning device? Will a worker confuse the audible warning with another warning sound? Will sound be obscured by background noise?

OSH 367 W4PPT1

7

Human-Machine Interaction

Safety professionals must work with all members of the safety system to plan for effective allocation of tasks and increase the efficiency of each component of the human-machine interaction.

OSH 367 W4PPT1

8

Matching Functions to Strengths

Industrial product systems consists of raw materials, machines, humans, and an end product.

Human machine interaction is a vital interaction that makes the system both effective and efficient.

Recognizing the strength of both and matching functions to the relevant strengths is key.

OSH 367 W4PPT1

9

Human Strengths

Human have these specific advantages over machines.

Sensory functions

Perceptual abilities (stimulus, generalizations, abstract concepts)

Flexibility (able to improvise)

Selective Recall

Inductive Reasoning

OSH 367 W4PPT1

10

Machine Strengths

Machines have these specific strengths over humans:

Alertness

Speed/Power

Sensor detection outside of human range

Routine Work

Computation

Short term memory

Simultaneous activities

OSH 367 W4PPT1

11

Human-Machine Interaction

Human and machine interaction relies on understanding the components of humans and machine interaction and allocating the job tasks and functions to the either human or machine based upon matching the strength to the task or function.

OSH 367 W4PPT1

12

Mo’ Technology - Mo’ Problems

OSH 367 W4PPT1

Rotary Phone

(1970’s)

Bag Phone

(1990)

13

In the US as production and demand for manufactured products increased so did the demands on the worker to produce and birthed the automation of machines and complex systems. These systems became very complex and initially automation of machines transferred task to that of machines. Technology has always contributed to shaping the way people interact with the world. Conversely, interacting with the world has direct impact on how technology evolves and it is constantly evolving.

Human interaction, with machines must begin to consider human design and engineering. As technology advances and evolves technology causes unusual and sometimes unwanted hazards that must be accounted for. Let review a few of these hazards. Are any of these devices memorable to you? Do you know what they are?

The first is a rotary phone… It worked well…. Ease of operation was minimal… Hazards associated with the rotary phone? Honestly don’t remember it been so long.

Dropped calls frequently

Sound quality was not good

Analog technology

Had to remember everyone phone number (no memory)

What do you think were some of the problems with a Bag Phone? Can you think of any?

Bad phone required a strong arm

Range of calls was not good

Dropped calls frequently

Required constant charging

Would not hold a charge long

Very expensive to own

13

Mo’ Technology - Mo’ Problems

OSH 367 W4PPT1

Flip Phones

(1996)

IPhones

(2007)

14

Here is a picture of a flip phone. What advances were made with the flip phones?

Smaller lighter then bag phone

Sound quality enhanced

Charging quicker

Longer battery life

What new hazards were created with a flip phone?

Texting and driving became an issue

Limited in capability

What advances were made with the iPhone? What new hazards were created?

Advances include

14

Human Capability

OSH 367 W4PPT1

16

What is Occupational Ergonomics?

Operating within human capabilities will allow us to benefit within:

Productivity

Quality

Safety

Operating outside our capabilities can result in:

Eventual damage and downtime

Reduced quality and performance

Page 9

OSH 367 W4PPT1

17

What we’re really striving for is what we call “Human Performance Ergonomics”.

This is a way to optimize human performance by ensuring the workplace supports both job task needs and employee capabilities.

Ergonomics is a Process, Not a Program

Page 10

OSH 367 W4PPT1

18

Ergonomics represents a journey of continuous improvement for the work place. This graphic illustrates the ergonomic improvement process. One of the most significant features of this process is that a basic awareness of ergonomics is needed to begin. However, once the process has begun, the cycle repeats itself continually.

World Class Athletes

OSH 367 W4PPT1

19

Lets switch gears here a little and talk about sports for a couple of minutes (like Andre Wilson from the UK Wildcats)

Athletes are wonderful models for human performance because they push every element of human capability to the maximum. At every practice and every competition, athletes are always striving to improve their performance. Whether they are attempting to win a race, break a record, or achieve an undefeated season, they are always trying to maximize their strengths and minimize their weaknesses.

In order to be a world class athlete, you have to have four partners. These include Skill, Will, Good Coaching, and Great Equipment.

Go through each of these explaining what you mean by all of them.

Also explain that you need all 4 of these to be successful, not 2, or 3, but all 4.

World Class Athletes

Skill

Will

Good Coaching

+ Right Equipment

World Class Athlete

Page 13

OSH 367 W4PPT1

20

Skill: Athletes must have the skill necessary to perform the basic activities of the sport. For example, basketball players must be able to run, jump, and shoot a basketball.

Will: Athletes must have the will or motivation necessary to practice and hone the skills of the sport in order to compete at their peak level of performance.

Good Coaching: Athletes need coaches who can help them to capitalize on their strengths and improve their weaknesses. Athletes often have a variety of different coaches including physical trainers, strength coaches, and nutritionists.

Great Equipment: Athletes also need the right equipment if they are going to enter the winners circle.

World Class Athletes

Performance Enabling

Performance Disabling

Page 13

OSH 367 W4PPT1

21

Here is a good example of some great equipment.

Did you ever notice that shoes tend to be designed with specific sports in mind. In fact, can you think of a sport that doesn’t have a shoe designed specifically for it, that doesn’t involve water?

A lot of time, money and engineering went into designing this pair of shoes. If the shoe is designed wrong, or you are wearing the wrong type of shoes for your sport, bad things tend to happen.

Go through 2 examples of sports where the athlete was wearing the wrong shoes (i.e. a bowler wearing a pair of cleats, or a basketball player wearing the bowlers shoes…)

In fact, supplying the proper equipment to the athlete is the most important of the four partners (Skill, Will, Coaching, Equipment).

Here is a picture of an athlete that is missing one of these partners.

World Class Athletes

OSH 367 W4PPT1

22

Q: What would happen if we replace Carl Lewis’ shoes with these high heels?

Explain that the starting gun is going to go off, and that he is going to try to run in these high heels. Have the class tell you what’s going to happen to this track athlete.

Q: Will he start the race?

A: Yes, because he has the will.

Q: Will he finish the race?

A: Yes, because he has the will. Whether he has to crawl on his hands and knees he has the determination to finish.

Q: Will he win the race?

A: No.

If this athlete was determined to learn to run in these shoes, with motivation and good coaching he would develop the necessary skills. But what will happen to his legs and feet as he continues to perform in this equipment day in and day out?

Eventually the bones in his legs and feet will adapt to the equipment that he is using. He may even develop a low back injury.

World Class Athletes

Page 14

OSH 367 W4PPT1

23

Explain that these types of injuries tend to start off as a hassle, become more painful over time and then turn into Work-Related Musculoskeletal Disorders

The track athlete in high heel shoes has developed a WMSD when the bones and muscles in his legs and feet adapt to the equipment the he is wearing.

Why have we been talking about sports for the last 15 minutes?

World Class Athletes

Page 14

OSH 367 W4PPT1

24

Explain that these types of injuries tend to start off as a hassle, become more painful over time and then turn into Work-Related Musculoskeletal Disorders

The track athlete in high heel shoes has developed a WMSD when the bones and muscles in his legs and feet adapt to the equipment the he is wearing.

Why have we been talking about sports for the last 15 minutes?

The Industrial Athlete

Skill

Will

Good Coaching

Right Equipment

TABC

Page 14

OSH 367 W4PPT1

25

It turns out that our people out there making our products are “Industrial Athletes”. They are doing the same sorts of physical activities. They are lifting, lowering, pushing, pulling, walking, running, possibly even throwing.

Much like our world class athlete, our industrial athlete needs the same four partners.

Is This the Right Way?

Is this (or what is) the right way?

Can everyone do it the right way?

Page 15

OSH 367 W4PPT1

26

Ergonomics is a common-sense way of looking at the workplace.

Every time we look at a job we must ask ourselves a fundamental question: Is this (or what is) the right way?

If the answer is No, then we must look for improvements until we can honestly say “we would do it this way”.

Ergonomics is an attitude, a way of looking at the workplace.

By thoughtfully reviewing a workstation layout, we are often able to identify what is wrong with the design and begin to develop solutions.

Posture, Force, and Frequency

Page 16

OSH 367 W4PPT1

27

In fire safety, a triangle is used to illustrate the three components that are needed to start a fire: oxygen, fuel, and an ignition source. This is called the fire triangle.

In much the same way, we have the 3 components that can increase our risk of developing WMSDs:

Posture – Posture is the alignment of your body segments in their joint range of motion; for every joint we have a limited range of motion.

Force – Force is how much you push, pull, lift and carry while working.

Frequency – Frequency exists on a continuum. At one extreme of the continuum exists high frequency, or repetition. At the other extreme of the continuum is the lack of frequency, or duration.

Keep in mind that each of these elements has an effect on the other two. For example, the amount of force that our bodies can generate depends on our body posture. Also, the amount of force that we can generate depends on the frequency with which we must perform a particular task.

This is the known as the ‘Ergo' fire triangle and the fire in this example is a WMSD.

Q: How do we prevent fires from occurring?

A: We remove one side of the fire triangle.

Q: How can we help prevent WMSDs?

A: Eliminate components of the triangle to put out the ‘ergo' fire.

How do WMSDs occur?

Posture

Extreme postures stress joints and occlude blood flow

Force

Tasks with forceful exertions place higher loads on joints and connective tissues

Frequency

Extreme frequencies – repetition can contribute to fatigue debt

Static duration - The longer the period of continuous work, the longer recovery time needed

OSH 367 W4PPT1

28

Posture is the alignment of our body segments within their joint range-of-motion.

Extreme postures are harmful as they stress joints and occlude blood flow.

Force is the amount of weight that we push, pull, lift or carry. Force can also be an applied force such as gripping a hand tool or pressing a part into place.

Tasks with forceful exertions place higher loads on joints and connective tissues.

Frequency is the number of movements and/or the duration of movements.

High repetitions and long durations can contribute to fatigue debt. The longer the period of continuous work, the longer the recovery time.

How do WMSDs occur?

WMSDs are based on a dose and response exposure relationship to ergonomic risk factors.

Presence of ergonomic risk factors:

Does not guarantee that a WMSD will occur

Does increase the chance for developing a WMSD

Supported by strong epidemiological research

OSH 367 W4PPT1

29

Read the slide and go through an example like the one listed below…you can use a flipchart to illustrate the concept.

Let’s take two groups, teeth-brushers and non-teeth brushers. It’s proven that people who do not brush their teeth have high risk of getting cavities.

But is it possible to get a cavity even if you do brush your teeth (ie. Me and my red wine drinking – no cavities but stains). You are at a significantly lower risk of cavities if you brush your teeth, but the risk is still there.

Instead of thinking about our time brushing, let’s present our operators with ergonomic risk factors such as force, frequency and posture.

Instead of cavities, what are they at risk of developing?

WMSDs

Is it possible to get a WMSD without force, frequency or posture at your job?

Yes, but the risk is lower. Just because you do have ergo risk factors, doesn’t mean you will get a WMSD, just that your chances are higher.

Ergonomic Risk Factors should be interpreted as one would consider any other risk factor. The presence of a risk factor does not necessarily predict that an individual will suffer a health problem as a result of exposure to the risk factor. Rather, a risk factor is a condition of the work place that increases one’s chance of developing a CTD and to which exposure should be limited, or totally avoided, in pursuit of a goal of a 100% healthy and safe working environment.

Improved Posture Reduced WMSDs

Risk Factors

Effects of wrist posture on WMSDs

OSH 367 W4PPT1

30

This graph illustrates the results of a study that compared the effect of two different types of pliers: traditional straight handled pliers and bent handled pliers.

Bent handled pliers were provided to one group of trainees to enable a straight wrist posture. According to the study, approximately 65% of the trainees that used the traditional straight pliers experienced tenosynovitis, epicondylitis, and carpal tunnel irritation, as opposed to 10% of the trainees that used the bent handled tool.

Effects of hand repetition and grasping force on WMSDs

Combination of Risk Factors

OSH 367 W4PPT1

31

As individual risk factors, Posture, Force, and Frequency are all significant. But when combined, these risk factors become much more important and contribute to wear and tear injuries at a greater rate than would be intuitive.

Additional Risk Factors

Physical stressors can accelerate the onset of WMSDs.

Vibration

Contact with vibrating objects can cause segmental or whole body vibration

Low temperatures

Regular exposure (more than 2 hrs./day) to temperatures below 66°F/18°C

High temperatures

Working in temperatures exceeding 82ºF/27°C increases muscular fatigue

Impact stress

Dynamic force to the body (e.g., using the hand as a hammer)

Soft tissue compression

Static force applied for prolonged time (e.g., elbows against a table edge)

Glove issues

Poorly fit gloves increase the force needed to grasp objects and limit dexterity

OSH 367 W4PPT1

32

Other factors that may accelerate the onset of WMSDs are what we call Physical Stressors.

These are things like vibration, low temperatures, impact stress, soft tissue compression, and glove issues.

Top 10 “At-Risk” Postures

OSH 367 W4PPT1

33

Ergo Eyes

Hit List

Fix It

Comfort Zone

Don’t Give Me Static

Find It

Horizontal Distance

Wash Rag

Contact

OSH 367 W4PPT1

34

By using the Hit List, you will gain a whole new perspective on people’s job. You’ll start to develop what we call “ergo eyes”, being able to spot what is ergonomically incorrect in the job, quickly and easily.

Find It

Wash Rag

Page 29

OSH 367 W4PPT1

35

The Hit List item Wash Rag is the condition of extreme wrist bending.

The precise names for these non-neutral wrist postures include radial and ulnar deviation, flexion and extension.

However, Wash Rag provides a simple, easy to remember way to visualize these postures.

A straight wrist posture is always best.

Wash Rag

TMMC

OSH 367 W4PPT1

36

Q: Do you see the Wash Rag posture that the operator assumes as he handles parts?

Wash Rag

Find It

OSH 367 W4PPT1

37

Q: What is causing this operator to assume a Wash Rag posture?

Elbows Out

OSH 367 W4PPT1

38

Elbows Out results when an operator tries to maintain a straight wrist posture.

The stress is transferred from the wrist to the elbow and it appears that the operator is winging his elbow out to the side.

Elbows Out is often the result of using screwdrivers to manually drive screws; employees often wing out the elbow during the continuous forearm rotation involved in the task. It is also found at workstations where the work is located too high off the standing surface.

Elbows Out postures can result in the compression of nerves between the muscles of the forearm and/or inflammation of the tendons at the elbow.

TMMC

Elbows Out

OSH 367 W4PPT1

39

Notice how obvious the Elbows Out posture obvious is in this picture.

TMMWV

Elbows Out

OSH 367 W4PPT1

40

Q: Do you see the Elbows Out posture in the picture?

Q: What potential improvements could we make to this workstation to eliminate the Elbows Out posture?

Shoulder Too High / Too Low

Page 31

OSH 367 W4PPT1

41

Shoulder Too High/Too Low reminds us that if the shoulder is too high, the job is too high, and if the shoulder is too low, the job is too low.

Repetitive bending over and reaching up are high risk postures that can contribute to WMSDs.

Some common Shoulder Too High/Too Low activities include poor storage heights for materials, improper working heights, seated computer work, and poor placement of switches, levers or buttons.

Shoulder Too High/Too Low

Find It

OSH 367 W4PPT1

42

This is a Shoulder Too High posture during a material handling process.

TMMWV

Shoulder Too High / Too Low

OSH 367 W4PPT1

43

This operator is assuming a Shoulder Too Low Posture while retrieving parts off shelves

Q: What would be an optimal height for this shelf?

A: Ideally the shelf would be at standing elbow height, but locating shelves between the operators’ standing shoulder height and standing knee height would eliminate the non-neutral shoulder posture for this task.

Hungry Head

Page 32

OSH 367 W4PPT1

44

Hungry Head refers to the search for visual information. The head is “Hungry for Information”.

If sight lines are not clear, or areas are poorly lit, the body will naturally position the eyes to be in the best position to see what they need to see.

Hungry Head conditions lead primarily to muscular pain in the neck and upper back/shoulder.

Over time, this posture may compress the nerves and restrict blood flow.

Common hungry head activities include looking through a microscope, performing small part assembly, inspecting parts, and reading dials or displays.

Hungry Head

Find It

TMMI

OSH 367 W4PPT1

45

TMMC

Hungry Head

OSH 367 W4PPT1

46

Butts Up

OSH 367 W4PPT1

47

Butts Up is the condition of bending over, thus extending the upper body over the floor.

This posture can generate extremely high compressive forces in the lower back muscles and the spinal discs located between the vertebrae.

What do you see on the shop floor? If you see a lot of “butts” instead of a lot of faces, it is because people must bend over to retrieve, handle, or place materials.

Butts Up

Find It

TMMWV

OSH 367 W4PPT1

48

Butts Up

Find It

TMMC

OSH 367 W4PPT1

49

Find It

Twist and Shout

Page 34

OSH 367 W4PPT1

50

Twist and Shout is the condition of twisting at the neck or back while performing work activities.

Twist and Shout postures commonly result from poor placement of shared tools, reaching across the body to retrieve parts, retrieval from bins, and excessive reaching to parts.

One way to identify Twist and Shout postures is to observe the location of the shoulders in relation to the hips. If you see that the shoulders are not in the same line as the hips, you have Twist and Shout postures.

Twist and Shout

Find It

OSH 367 W4PPT1

51

Twist and Shout

Find It

Buffalo, WV. – Transmissions – AT 6 Speed

TMMI

OSH 367 W4PPT1

52

Horizontal Distance

Page 35

OSH 367 W4PPT1

53

Horizontal distance is the condition of working far away from the body.

If the work activity requires a far reach, the potential for ergonomic risk to the shoulders and back increases.

Horizontal Distance also increases the time necessary to complete an activity.

Reaching may be necessary, but excessive reaching is wasteful and inefficient.

Class Exercise

OSH 367 W4PPT1

54

Horizontal Distance

OSH 367 W4PPT1

55

Horizontal Distance

OSH 367 W4PPT1

56

Because the area behind the operator is used to palletize outgoing product, this operator must repetitively reach across the conveyor to retrieve incoming product.

As a result, he reaches over a long Horizontal Distance.

This posture could also be recorded as a Butts Up posture.

The workstation layout and product flow through this department should be modified in order to eliminate this excessive reach distance.

Sit vs. Stand

OSH 367 W4PPT1

57

At each workstation, we want to carefully consider when the operator should be sitting or standing while they perform the work activities.

Operators should be Seated for jobs that involve high visual attention, fine finger motions, and long processing times.

Operators should be Standing for jobs that require operator mobility, moderate application of forces, and where work activities vary from one product to another.

For sitting tasks, it is important to provide a proper chair with good lumbar support and height adjustability, foot support, and adequate leg clearance.

For standing tasks, anti-fatigue matting and foot rails are recommended to promote circulation and minimize fatigue.

Sit vs. Stand

OSH 367 W4PPT1

58

Sit vs. Stand

OSH 367 W4PPT1

59

Sit vs. Stand

OSH 367 W4PPT1

60

This operator is assembling wires to a harness board

Bad Vibes

OSH 367 W4PPT1

61

Bad Vibes is a condition in which the employee is exposed to vibration.

Exposure to vibration from hand tools can permanently damage the small blood vessels and nerves in the fingers.

Vibration also induces muscle fatigue because the gripping force required to hold, control, and use the tool increases.

Vibration exposure to the hand and forearms is considered segmental vibration.

Operating a cutting tool, as shown here, is an example of segmental vibration.

Entire body vibration has also been shown to increase employee discomfort, disorientation, and joint degeneration in the feet and knees.

A common example of exposure to whole body vibration is driving a fork truck.

Bad Vibes

Find It

TMMK

OSH 367 W4PPT1

62

Bad Vibes

Find It

TABC

OSH 367 W4PPT1

63

Bad Vibes

OSH 367 W4PPT1

64

Contact

OSH 367 W4PPT1

65

The last Find It item on your Hit List is Contact.

Contact is another name for soft tissue compression.

Contact occurs when the operators’ soft tissues come in contact with a hard or sharp piece of equipment or tool edge.

The soft tissues that typically come in contact with equipment and tooling include the legs, abdomen, forearms, or the palms of the hands.

Contact increases the force component of the job while reducing the blood flow to the affected body area.

Contact may also lead to skin irritation, while continued contact may cause blood vessels to compress and the skin to harden.

Common Contact activities include leaning elbows against a hard table edge, holding sharp or pointy tool handles, and leg interference under the work table while seated.

Contact

Find It

OSH 367 W4PPT1

66

Contact

Find It

OSH 367 W4PPT1

67

Let’s Practice!

Which Hit List items do you see in the picture?

Wash Rag

Elbows

Out

Shoulders

Too High/Low

Hungry

Head

Butts Up

Twist and Shout

Horizontal

Distance

Sit vs. Stand

Bad Vibes

Contact

OSH 367 W4PPT1

68

Let’s Practice!

Which Hit List items do you see in the picture?

Shoulders

Too Low

Hungry

Head

Butts Up

Twist and Shout

Contact

Wash Rag

Elbows

Out

Shoulders

Too High/Low

Hungry

Head

Butts Up

Twist and Shout

Horizontal

Distance

Sit vs. Stand

Bad Vibes

Contact

OSH 367 W4PPT1

69

Let’s Practice!

Which Hit List items do you see in the picture?

Wash Rag

Elbows

Out

Shoulders

Too High/Low

Hungry

Head

Butts Up

Twist and Shout

Horizontal

Distance

Sit vs. Stand

Bad Vibes

Contact

OSH 367 W4PPT1

70

Let’s Practice!

Which Hit List items do you see in the picture?

Elbows

Out

Shoulders

Too High/Low

Hungry

Head

Wash Rag

Elbows

Out

Shoulders

Too High/Low

Hungry

Head

Butts Up

Twist and Shout

Horizontal

Distance

Sit vs. Stand

Bad Vibes

Contact

OSH 367 W4PPT1

71

Fix It: Three solution strategies to identify low cost/high impact job improvements.

Ergonomics Hit List – “Fix It”

Page 39

OSH 367 W4PPT1

72

The Fix It section of the Hit List provides three solution strategies to identify low cost and high impact job improvements.

Tool/Target, Comfort Zone, and Don’t Give Me Static combined with the perspective of “Would you do it this way?”, can be used to pinpoint practical job improvements that affect operator comfort, health, and performance.

We will now discuss each of these Fix It items with examples from various industries.

Tool/Target

Page 41

OSH 367 W4PPT1

73

Tool/Target helps you to resolve ergonomic issues that arise from a mismatch between the employee and the workstation and/or tool that is being used.

Changing either the Tool that is used or the Target location can improve all ergonomic issues.

Tools are designed for a specific application in a specified direction. If a person uses the wrong tool for the job or the target is in the wrong location, he or she may assume non-neutral postures such as Wash Rag or Elbows Out.

Some general guidelines for changing the Tool include:

Using a pistol grip tool when applying a horizontal force on a vertical surface.

Using an in-line tool when applying a vertical force on a horizontal surface.

Some general guidelines for changing the Target include:

Providing a jig or fixture to orient the part for easy access.

Providing adjustable height tables.

Keep in mind that when an employee does not use a specific tool, then the tool is the operator’s hand.

Tool/Target

Find It

High force, awkward postures

Fix It

Rotated the position of the storage racks

OSH 367 W4PPT1

74

Tool/Target

Find It

Wash Rag

Bad Vibes

Fix It

Provided an inline driver to reduce wash rag postures

Provided padding on handle

OSH 367 W4PPT1

75

Fix It

Comfort Zone

OSH 367 W4PPT1

76

Working near the limits of a joint’s range of motion is difficult and increases exposure to ergonomic risk.

The Comfort Zone is made up of the natural, semi-circular movements or motions of the human body.

The maximum Comfort Zone extends from our shoulders to our knees, and no more than 20 degrees to either side of our body.

The optimal Comfort Zone is located a few inches above and below our elbow height, and directly in front of our body.

The Comfort Zone is where we are the strongest, possess and execute the most control, and have the best visual acuity.

Working inside the Comfort Zone reduces the time necessary to perform work activities as unnecessary movements are eliminated.

Comfort Zone

Find It

Butts Up

Shoulders too Low

Fix It

Fabricated a cart to raise the height of the rods

OSH 367 W4PPT1

77

Comfort Zone

Find It

Butts Up

Shoulders too Low

Fix It

Provided a lifter for bump and dent repairs

OSH 367 W4PPT1

78

Don’t Give Me Static

Page 44

OSH 367 W4PPT1

79

Don’t Give Me Static is a way to remember that our bodies rely on good blood flow.

Blood flow is critical to maintaining operator performance and connective tissue and nerve health.

Soft tissue compression can impede blood flow to the muscles, connective tissues, and nerves.

Soft tissue compression results from prolonged static force applications such as gripping and carrying.

Exposure to vibration or contact with hard or sharp edges can also restrict blood flow.

Don’t Give Me Static

Find It

Hard, thin handle

Fix It

Padded full-grip handle

OSH 367 W4PPT1

80

This operation involves horizontally sliding a heavy assembly fixture back and forth at various points in the assembly process.

U-shaped handles were initially mounted on the sides of the table.

The original handles were very narrow in diameter making then difficult to grasp.

Also, the hard surfaces of the handles resulted in contact stress to the operator’s hands.

The Fix It improvement idea for this operation was to mount padded handles that would allow the operator to use a power grip while grasping and sliding the heavy fixture.

The new handle design eliminated Wash Rag postures as well as Don’t Give Me Static issues.

Don’t Give Me Static

Find It

Sharp Edges

Fix It

Padding to reduce contact stress

OSH 367 W4PPT1

81

Don’t Give Me Static

Find It

Worn matting

Trip hazard

Fix It

Replaced anti-fatigue matting

TMMK

OSH 367 W4PPT1

82

Ask the Operator: The most important data source for identifying and resolving ergonomics issues is the operator.

Ask the Operator

Page 45

OSH 367 W4PPT1

83

Finally, at the very bottom of the Hit List card is this statement Ask the Operator.

Ask the Operator appears at the bottom of the card because it is the foundation of this entire process and key to success.

The operator is the most important data source for identifying and resolving ergonomics issues.

Ask The Operator

Expert

Hit List

Ask the Operator

OSH 367 W4PPT1

84

The real expert in any operation is the person who does it every day.

Ask the operator to identify the ergonomic problems that you might otherwise miss.

Share Success: A reminder to share successful improvements with other areas that have similar challenges.

Check for Success: Confirm that Fix It improvements resolve Find It issues (and don’t create additional concerns).

Continuous Improvement Process

OSH 367 W4PPT1

85

The back of the Ergonomics Hit List provides several important elements to help you understand how to get the most out of the Find It and Fix It approach.

As we have learned up to this point, finding and fixing ergonomic issues are important steps in the ergonomics process.

We Check for Success to confirm that Fix It improvements resolve Find It issues and don’t create additional concerns.

Checking for Success involves repeating the Find It – Fix It steps of the ergonomics process.

As I mentioned at the start of the presentation, the key to any continuous improvement process is stopping to Check for Success.

By taking the time to check for success, we can make the changes that are necessary for us to improve our performance the next time that we cycle through the process.

FORM is Fix Once – Repeat Many. FORM is a reminder to share successful improvements with other areas that have similar challenges.