Ergonomics

What is Ergonomics?

October 15, 2024 By Ararso T

 Introduction
• ERGO = “work”

• NOMICS= “rules” or “laws”

• Ergonomics literally means “the laws of

work”

• OSHA defines ergonomics as the science of “designing

the job to fit the worker, instead of forcing the worker to
fit the job.”

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 Introduction cont…
• Ergonomics is the science of adapting workstations,
tools, equipment, and work methods for more
efficient, comfortable, and error-free use by
humans

• Ergonomics incorporates all factors affecting work

including, job demands, personal characteristics, and
environmental conditions

October 15, 2024 By Ararso T

 Introduction cont…
• Ergonomics addresses the mismatch between task
requirements and worker capabilities
• Ideally, ergonomics:
– Makes the job safer by preventing injury and
illness
– Makes the job easier by adjusting the job to the
worker
– Makes the job more pleasant by reducing
physical and mental stress
– Saves money
October 15, 2024 By Ararso T
 Ergonomic study areas

• WORKERS - what they bring to the job

• TOOLS - what they bring to the worker
• TASKS - what the worker must do
• ENVIRONMENT- the conditions surrounding the
worker and the tool

October 15, 2024 By Ararso T

 Ergonomic focus

The
The Tool Task

The User
/Operator
The Work
Station and
Environmen
t
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Ergonomic assist equipment

• This type of material handling equipment

can be categorized within two broad
classifications of motion, consisting of
1. moving the worker to the product, and
2. moving the product to the worker.
• Schematic diagrams of the various
motions involved are shown in Fig. 1.

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Moving the worker

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adjustable worker elevation platform
Moving the product

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Manipulators

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Vacuum Lifters

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Workstation Cranes

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Workstation

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 Ergonomic Factors

• Two Categories of Ergonomic Factors

1. Environmental

2. Physical

October 15, 2024 By Ararso T

 Environmental Factors
• Environmental factors may affect:
– Hearing
– Vision
– General comfort and health

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 Environmental Factors cont…

• Some examples of ergonomic environmental

problems are:

– Excessive noise
– Improper lighting
– Temperature extremes

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 Physical Stressors
• Physical stressors place pressure or stress on
parts of the body:

– Joints, muscles, nerves, tendons, bones

• Sometimes these injuries are referred to as

“Cumulative Trauma Disorders” (CTDs) or
“Repetitive Strain Injuries” (RSIs)
October 15, 2024 By Ararso T
 Ergonomic risk factors
• Main risk factors
1. Force
2. Repetition/Duration
3. Posture
4. Contact trauma
• Efforts to control ergonomic risk focus on these
factors
– Other factors also are involved
• Environmental, personal

October 15, 2024 By Ararso T

 Risk Factors: Repetition
• The majority of CTDs are caused by repetitive motions
that would not result in injury if only performed once.

– Thousands of keystrokes typing

– Hours of filing, day after day

– Stamping dozens of papers

– Frequent lifting

– Repeated motions with computer mouse

October 15, 2024 By Ararso T

 Risk Factors: Awkward Positions
• Leaning forward at your desk
• Typing with wrists at an odd angle
• Raising shoulders while typing
• Reaching to use mouse
• Twisting neck to look at monitor or phone
• Lifting objects from below waist or above
shoulders
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 Risk Factors: Excessive Force
• Typing with too much force or “pounding”
the keys
• Stamping
• Lifting heavy boxes of paper or carrying
office equipment
• Using improper grip

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 Ergonomic diseases/injuries
• Cumulative Trauma Disorder (CTD)
– Also known as Repetitive Strain Injury (RSI)
• Cumulative = occurring gradually over a
period of weeks, months, or years
• Trauma = bodily injury to nerves, tissues,
tendons, or joints
• Disorders = physical ailments or abnormal
conditions

October 15, 2024 By Ararso T

Ergonomic diseases/injuries

• CTDs includes:

1. Musculoskeletal disorders, MSDs

– Upper Extremity MSDs

– Low-Back MSDs

2. Nerve disorders

3. Neurovascular disorders

October 15, 2024 By Ararso T

 Cumulative Trauma Disorders
• Musculoskeletal disorders, MSDs

– Tendinitis (also tendonitis)

• Inflammation of the tendon

– Tenosynovitis

• Inflammation of the tendon sheath

– Epicondylitis

• Inflammation of the tendon attachment at the

elbow
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 Cumulative Trauma Disorders
• Nerve disorders
– Carpal tunnel syndrome
• Compression of the median
nerve in the carpal tunnel of the
wrist
• Tingling and numbness of the
thumb and first three fingers

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 Cumulative Trauma Disorders
• Neurovascular disorders

– Thoracic outlet syndrome

• Compression of shoulder nerves and veins

– Arm pain, numbness, or impaired circulation to

the extremities

– Raynaud's phenomenon

• “Vibration white finger”

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 What are Musculo Skeletal Disorders?

MSDs are injuries and illnesses that affect muscles, nerves,

tendons, ligaments, joints or spinal discs.
Musculoskeletal Disorders: Signs and Symptoms
• Decreased grip and/or • Tingling
pinch strength • Pain
• Cramping
• Swelling
• Stiffness
• Fatigue

• Loss of function

• Numbness

• Burning sensation
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Common Body Parts Prone To Workplace MSDs

• Back - Lower

• Neck and Upper Back

• Upper Extremities - Arms and Hands

• Lower Extremities - Legs and Feet

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Developing Controls

• Types of Controls
1. Engineering Controls: Reduce or Eliminate
Potentially Hazardous Conditions
2. Administrative Controls: Changes in Work
Practices and Management Policies
3. Personal Equipment

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Engineering Controls - Design
the Job
• Workstation Layout
• Selection and Use of Tools
• Work Methods

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Strategies for Job Design

• Change the Way Materials, Parts, and Products

Can Be Transported (e.g., use mechanical assist
devices rather than manual handling)
• Change the Process or Product to Reduce Risk
Factors

October 15, 2024 By Ararso T

Strategies for Job Design

• Modify Containers and Parts Presentation (e.g.

height adjustable material bins, etc.)
• Change Workstation Layout (e.g., use height
adjustable workbenches, etc.)
• Change the Way Parts, Tools, and Materials are
to be Manipulated (e.g., use fixtures to hold work
pieces, etc.)

October 15, 2024 By Ararso T

Strategies for Job Design

• Change Tool Designs (e.g., pistol handle grips

for knives to reduce wrist deviations, etc.)
• Change Assembly Access and Sequence (e.g.,
remove physical and visual obstructions, etc.)

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Administrative Controls

• Reduce Shift Length or Curtail Overtime

• Rotate Workers Through Several Jobs With
Different Physical Demands
• Schedule More Breaks for Rest and Recovery

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Administrative Controls

• Broaden or Vary Job Content

• Adjust the Work Pace
• Train Workers to Recognize Risk Factors for
MSDs
• Instruct Workers in Work Practices That Can
Ease Task Demands

October 15, 2024 By Ararso T

PPE- Is it Effective?

• Wrist Supports, Back Belts, Vibration Attenuation

Gloves
• Are Not a Barrier Against Risk Factors for MSDs
(as hard-hats, safety shoes, safety goggles, etc.,
are barriers against hazards)
• Evidence of Their Effectiveness Remains
Inconclusive

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Gathering Ideas for Controls

• Trade Associations May Have Information About

Good Control Practices
• Insurance Companies that Offer Loss Control
Services
• Consultants and Vendors Who Deal in
Ergonomic Specialty Services and Products
• Visits to Other Worksites Known to Have Dealt
With Similar Situations

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 Implementing Controls
• Trials or Tests of Selected Solutions
• Making Modifications or Revisions
• Full Scale Implementation
• Follow-Up to Evaluate Control Effectiveness

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 Implementing Controls
• Designate the Personnel Responsible
• Create a Time-table
• Consider the Logistics Necessary for
Implementation

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Evaluating Control Effectiveness
• Use Risk Factor Checklist or Other Job
Evaluation Method
• Repeat Symptoms Survey and Compare With
Prior Results (often in conjunction with checklist
or other job analysis method)
• Should Occur 1 - 2 Weeks After Implementation
(short term evaluation)

October 15, 2024 By Ararso T

Evaluating Control Effectiveness
• Long Term Evaluations
– Reduction in Incidence Rate of MSDs
– Reduction in Severity Rate of MSDs
– Increase in Productivity or Quality of Products
or Services
– Reduction in Job Turnover or Absenteeism

October 15, 2024 By Ararso T

Health Care Management - Employer
Responsibilities
• Provide Education and Training Regarding
Recognition of Symptoms and Signs of MSDs
• Encourage Early Reporting of Symptoms and
Prompt Evaluation by Care Provider
• Give Care Provider Opportunities to Become
Familiar With Jobs and Tasks
• Modify Jobs/Tasks or Accommodate Limitations
• Ensure Privacy of Medical Information

October 15, 2024 By Ararso T

 Health Care Management - Employee
Responsibilities

• Follow Workplace Safety and Health Rules

• Follow Work Practice Procedures Related to
Their Jobs
• Report Early Any Signs or Symptoms of MSDs

October 15, 2024 By Ararso T

Health Care Management - Health
Care Provider Responsibilities

• Acquire Experience and Training in Evaluation

and Treatment of MSDs
• Seek Information and Review Materials
Regarding Employee Job Activities
• Ensure Employee Privacy and Confidentiality
• Evaluate Symptomatic Employees

October 15, 2024 By Ararso T

 Health Care Management - Health
Care Provider Responsibilities
• Evaluate Symptomatic Employees, Including...
– Medical Histories and Symptoms
– Descriptions of Work Activities
– Physical Examinations
– Initial Assessments or Diagnoses
– Consider Opinions as to Whether
Occupational Risk Factors Caused,
Contributed to, or Exacerbated Conditions
– Follow-Up Examinations to Document
Improvements
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 Health Care Management - Health
Care Provider Responsibilities

• Become Familiar With Employee’s Job or Tasks

• Do Periodic Walk-throughs of the Plant
• Review Job Analysis Reports or Job
Descriptions
• Review Photographs or Videotapes of Jobs or
Tasks

October 15, 2024 By Ararso T

 Early Reporting
• Employers Should Encourage Early Reporting
• Employers Should Not Establish Policies Which
Discourage Reporting of Symptoms
• Provide Symptomatic Employees Prompt Access
to Evaluation by Health Care Provider

October 15, 2024 By Ararso T

 Treatment and Restricted Work
• Care Providers Should Determine Physical
Capabilities and Work Restrictions of Affected
Workers
• Employers Should Assign Workers to Tasks
Consistent With Restrictions
• Use Light Duty or Temporary Job Transfers
• Avoid Complete Removal From Work

October 15, 2024 By Ararso T

 Proactive Ergonomics
• To Emphasize Ergonomics at the Design Stage
of Work Processes
• To Design Operations That Ensure Proper
Selection and Use of Tools, Job Methods,
Workstation Layouts, and Materials
• Build a More Prevention-Oriented Approach
Using Knowledge Gained From the Ongoing
Ergonomics Process

October 15, 2024 By Ararso T

Proactive Ergonomics

• Design Strategies Should Emphasize Fitting Job

Demands to the Capabilities and Limitations of
Workers
• Design Strategies Should Target Causes of
MSDs - Engineering Approaches are Preferred
Over Administrative Approaches

October 15, 2024 By Ararso T

Goals of Ergonomics Program
• Reduce work-related musculoskeletal
disorders developed by workers when their jobs
involve...
• Awkward postures • Repetition
• Static positions • Contact stress
• Reaching • Vibration
• Bending & Lifting • Repetition
• Force

October 15, 2024 By Ararso T

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