Transcript What is Ergonomics? - AURA-O

ERGONOMICS
Recognition of Work-Related
Musculoskeletal, Nerve
Disease
What is Ergonomics?
• Ergonomics is the science of fitting
the job to the worker.
• Ergonomics refers to a work
environment designed to maximize
safety and increase productivity.
What is Ergonomics Gone
Bad?
• When there is a mismatch between the
physical requirements of the job and the
physical capacity of the worker, workrelated musculoskeletal disorders
(MSD) may result.
Ergonomic Disease
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Repetitive motion injury
Cumulative trauma disorder
Musculoskeletal disorder (MSD)
Repetitive stress injury
Sprains, strains, tears
Musculoskeletal Disorders
• Injuries or disorders of:
– muscles
– tendons
– ligaments
– nerves (compression or entrapment)
– spinal discs
– joints and cartilage
Signs and Symptoms
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Muscle pain
Joint pain
Swelling
Numbness
Restricted motion
Low back pain
Musculoskeletal Disorders
• Upper Extremities
• Hands
• Arms
• Shoulder
• Neck
• Upper Back
• Lower Back
• Feet and Legs
Benefits of Good
Ergonomics
• Decreased injury
risk
• Increased
productivity
• Decreased
mistakes/rework
• Decreased lost work
days
• Decreased turnover
• Improved moral
Risk Factors for Ergonomic
Hazards
Repetitive Motion/Cycle
• Same repetitive task
• Use of same muscle groups
• Short cycle (~<2/min)
Awkward Posture
Twisting
Overhead Reach
Force
• Heavy lifting
• Forceful exertions, pulling, pushing,
twisting
Contact Stress
• Using the hand or knee as a “hammer”
Vibration
• Whole body vibration
– e.g.., Crane operators, truck drivers
• Segmental vibration
– Pneumatic tools, grinders
Risk Factors Also
Depend On:
• Duration of stress
• Amount of recovery time
• Temperature
– Decrease blood flow to muscles
(cold)
And a Higher Risk Occurs
When:
• Risk factors are multiple
Controlling Ergonomic
Hazards
Control Hierarchy
1) Engineering controls
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Physical changes
2) Administrative controls
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Employee rotation
Change of pace
Job enlargement
3) Work practice controls
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Utilization of better procedures, posture
4) Personal Protective equipment
Manual Material Handling
and Back Protection
Acute vs. Chronic Stressors
• Acute:
– Where the injury arises from a single identifiable
event - when transient loads exceed internal
tolerances.
• Chronic:
– Where repeated trauma (albeit incapable of injury
in isolation), after sufficient duration, reduces
internal capacity resulting in eventual injury.
– Microtrauma
Back Injury
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Muscle
Ligament
Vertebrae
Discs
Ergonomic Risk
Factors for Backs
• Awkward posture
• Sitting
• Static, bent
postures
• Fatigue/aging
• Whole body
vibration
Ergonomic Risk
Factors for Backs
• Handling excessive
weight/force
• Load size
• Frequency of lifting
• Grip consideration
• Poor physical
condition
Kinds of Back Injuries
• Back strains-When weak or tense muscles are
stretched beyond their limit
• Back sprains-A partial or complete tear of a back
ligament
• Herniated discs-Resulting when stress, strain or
gradual deterioration on a disc causes it to stick
out between the vertebrae
• Ruptured discs-When the wall of a disc breaks
open.
Upper Extremities WorkRelated MSDs
Effects
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Pain
Inflammation
Swelling
Numbness
• Decrease in
range of motion
• Loss of function
• Cycle of injury
UECTD Risk Factors
Awkward Wrist Postures
Tendon Disorders
• Tendonitis:
– Fibers can become inflamed, fray or tear
apart, tendons can thicken, become bumpy
and irregular and without sufficient recovery
time become permanently weakened
Tendon Disorders
• Epicondylitis
• Lateral epicondylitis
- tennis elbow
(inflammation of
tendon fibers outside of elbow)
Source: American Society for Surgery of the Hand
• Medial epicondylitis or
golfers elbow (inside)
Tendon Disorders
Rotator cuff tendonitis
• Repetitive overhead work
• Elevated elbows
Source:NIH, Medline Plus
Tendons
• Stenosing Tenosynovitis (progressive
restriction of the synovial sheath)
• De Quervain’s disease (thumb tendons)
Tendons
Tenosynovitis (injury of the synovial sheath)
• Trigger finger (stenosing
tenosynovitis crepitans)
• Ganglionic cyst (swelling
of the synovial fluid)
Source: Cleveland Clinic
Nerve Disorders
• Injuries or disorders of the median nerve:
– Carpal tunnel syndrome (compression of he median nerve as it
passes through the carpal tunnel)
– Pronator syndrome (compression of median nerve as it passes
between the two heads of the pronator teres muscle)
Cubital Tunnel Pain/Numbness
www.medicalmultimediagroup.com
Bursitis
• Shoulder Bursitis
- Bursa irritated and
thickens with overuse
Neurovascular Disorders
• Thoracic outlet syndrome
- Caused by compression
of the neurovascular
bundle from repetitive
activities overhead or
with the arm pulled down
towards the back
Neck Disorders
• Tension or ache in the neck (local
muscle tightness/spasm)
• Numbness in the arms or hands (nerve
impingement)
Lower Extremities WorkRelated MSDs
Knee Disorders
• Bursitis of the knee
• Chondromalacia: degeneration
(softening) of the cartilage on the
posterior aspect of the kneecap
Lower leg disorders
• Shin splints: involve damage to
one of two groups of muscles
along the shin bone (caused by
standing for a long time or
repetitive stress to the lower
leg)
Foot Disorders
• Plantar fasciitis (inflammation of the
plantar fascia--the tissue that forms the
arch of the foot)
• Tarsal tunnel syndrome
(entrapment of the tibial
nerve)
Work Tool Design
• Reduce forces
Work Tool Design
• Use power grip
Work Tool Design
• Use optimal grasp span
Work Environmental
Concerns
(Heat Stress,Energy
Expenditure and Vibration)
Heat Disorders
• Heat stroke
• Heat exhaustion
• Heat cramp
• Heat collapse
• Heat rash
• Heat fatigue
Heat Stress Operations
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Iron and steel foundries
Nonferrous foundries
Brickfiring and ceramic plants
Glass product facilities
Rubber product factories
Factors Affecting
Susceptibility to Heat
• Age
• Weight
• Degree of physical fitness and
acclimatization
• Metabolism
Environmental Factors
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Air movement
Humidity
Conduction
Radiant heat exchange
Engineering Controls
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Ventilation
Air cooling
Fans
Shielding
Insulation
Types of Vibration
• Whole Body
• Hand-Arm (HAVS)
Summary
• When there is a mismatch between the physical
requirements of the job and the physical capacity
of the worker, work-related musculoskeletal
disorders (MSD) may result.
• Risk Factors for ergonomic hazards:
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Repetitive motion cycle
Awkward posture
Force
Contact stress
Vibration
• Upper extremities work-related MSD’s
• Lower extremities work-related MSD’s