what is ergonomics? ergonomics - wordpress.com · 2019-11-07 · osha 30 – ergonomics. osha...
TRANSCRIPT
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
ERGONOMICS
OSHA Oregon Office of Training and Education
o The study of work and the relationship of work to
the physical and cognitive capabilities of people
o Fitting the job (tools, tasks, and environment) to the
employee, instead of forcing the worker to fit the
job
What is Ergonomics?
OSHA Oregon Office of Training and Education
Ergonomics' Why it is important – Prevent Injuries
Musculoskeletal Disorders (MSD’s)
o Injury to soft tissue caused by prolonged
exposure to multiple ergonomic risk factors
o Also referred to as Cumulative Trauma Disorders
(CTDs)
o Can affect back, shoulders, arms, wrists, neck,
etc.
OSHA Oregon Office of Training and Education
CTD Trauma Bucket Balanced
Your Job
Your Body
Trauma
Healing Valve
OSHA Oregon Office of Training and Education
Your Job
Your Body
Trauma
Healing Valve
CTD
CTD
CTD Trauma Bucket Unbalanced
OSHA Oregon Office of Training and Education
Financial Impact of Top 10 Workplace Injuries
$$$$$$$$$o Overexertion 12.5 Billions
o Falls on same level 5.7
o Bodily reaction 4.7
o Falls to lower level 4.1
o Struck by objects 3.9
o Highway incident 2.3
o Struck by object 1.9
o Caught in 1.7
o Assaults and Violent acts 0.4
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Some Common Upper Extremity CTD’s
o Tendonitis—Tendon Disorder
o Tenosynovitis
o Trigger Finger
o Epicondylitis
o Thoracic Outlet Syndrome—Neuro Vascular Disorder
o Carpal Tunnel Syndrome—Nerve Disorder
OSHA Oregon Office of Training and Education
Types of WMSDs
Tendon disordersoTendons connect
muscles to bones.
oTendon disorders typically occur at or near the joints where the tendons rub ligaments and bones.
Applied Industrial Ergonomics
WMSDs
OSHA Oregon Office of Training and Education
Tendon and Tendon Sheaths
Synovial sheath
Tendon
Carpal ligament
OSHA Oregon Office of Training and Education
Tendinitis
Inflammation of the tendon
Tenosynovitis
Inflammation of the tendon
and the tendon sheath
Types of WMSDs (Work related musculoskeletal disorder)
Applied Industrial Ergonomics
OSHA Oregon Office of Training and Education
a
MEDIANNERVE
CARPALLIGAMENT
TENDONSBONES
Types of WMSDs
Nerve disorders
oResult from nerve entrapment or pressure on the nerve either by muscle swelling and/or irritation by the surrounding tendons or muscles
o Impede blood flow, oxygenation, and nerve signal transmission
Applied Industrial Ergonomics
WMSDs
OSHA Oregon Office of Training and Education
Types of WMSDs
Neurovascular disordersoAffect both nerves and nearby
blood vessels
oMay lead to reduced circulation, resulting in less oxygen and nutrients to the muscles
Applied Industrial Ergonomics
WMSDs
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Applied Industrial Ergonomics
Tendon Mechanics
OSHA Oregon Office of Training and Education
Muscle Blood Usage
Resting Dynamic Static
Blood flowneeded
Bloodflow
supplied
Bloodflow
needed
Bloodflow
needed
Bloodflow
supplied
Bloodflow
supplied
OSHA Oregon Office of Training and Education
Risk Factors = Ergonomic
Hazards
Force
Posture
EnvironmentalMechanicalcompression
Repetition
Vibration
Duration/Staticexertion
OSHA Oregon Office of Training and Education
Risk Factors
oRepetitionoForceful ExertionoDirect Mechanical PressureoStatic PostureoInadequate Recovery TimeoAwkward PostureoEnvironmental Stressors
OSHA Oregon Office of Training and Education
Repetition – Force –Awkward Posture
OSHA Oregon Office of Training and Education
Based on Medical Definition of RepetitivenessOccasional - 1% to 33% of an 8-hour
workday is spent performing this task
Frequent - 34% to 66% of an 8-hour workday is spent performing this task
Continuous - 67% to 100% of an 8-hour workday is spent performing this task
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Hand and wrist
Elbow
Shoulder
Neck
Back
Legs
> 30 Deficient postures or manipulations
Per minute
> 2 Deficient postures
Per minute
> 2 Deficient postures
Per minute
> 2 Deficient postures
Per minute
> 2 Deficient postures
Per minute
> 2 Deficient postures
Per minute
Risk factors
Repetition Frequency
OSHA Oregon Office of Training and EducationFlexed 45°
Extended 45°
Hands/Wrists
OSHA Oregon Office of Training and EducationRotated forearm
Elbow
OSHA Oregon Office of Training and Education
Arm raised 45°
Shoulders
OSHA Oregon Office of Training and Education
Sideways Twisted 20°
Neck
OSHA Oregon Office of Training and Education
Squat Kneel Unsupported
Legs
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Repetition:
o Use power tools when available
o Change tasks or take a break from
repetitive tasks
o Follow job rotation policies where
applicable – effective job rotations
work alternate muscle groups
between successive job functions
Ergonomic Tips to Minimize Repetition
OSHA Oregon Office of Training and Education
Ergonomic Tips to Minimize Vibration & Torque
o To lessen vibration:
• Pad tool handles with a soft compressible surface
• Use vibration damping (gel filled) gloves
• Select tools (hammers and chippers) with built in damping systems (springs/hydraulics)
o To lessen torque reaction:
• Use electric tools as opposed to air driven tools
• Use pulse tools or auto-shutoff tools
OSHA Oregon Office of Training and Education
Awkward postures and prevention options
OSHA Oregon Office of Training and Education
When this employee picks up the 30 lb box, and his arms are fully extended, when
placing the box on the pallet. It places 300 psi 10 x the weight of the box on his spine.
•Off loading of 30lb boxes. 830 boxes/shift @ 30lbs = 25000 lbs / 2 operators, 6 tons
each, per shift.
The lift analysis shows @ 1- 30 lb lift every minute, is only acceptable for 21%
of your female work force.
OSHA Oregon Office of Training and Education
Improvement/ suggestion:
•Extend the slot conveyor over to the pallet/lift table.
•Eliminate the lift, and allow the operator to slide the box onto the pallet.
OSHA Oregon Office of Training and Education
o Avoid overhead reaching and
kneeling when possible
Ergonomic Tips to Minimize Awkward Postures
o Work near elbow height to avoid
bending excessive bending
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Ergonomic Tips to Minimize Awkward Postures
Where awkward postures are
unavoidable, change tasks, stretch,
and take short breaks frequently
OSHA Oregon Office of Training and Education
Ergonomic Tips to Minimize Awkward Postures
o Select the correct tool handle orientation based upon work
surface height/orientation (when possible)
Primary Use Surface Orientation Select this tool type
Above shoulder
height
vertical surface in-line grip
horizontal surface pistol grip
Between elbow and
shoulder height
vertical surface pistol grip
horizontal surface in-line grip
Below elbow heightvertical surface in-line grip
horizontal surface pistol grip
Pistol grip In-line grip
OSHA Oregon Office of Training and Education
Ergonomic Tips to Minimize Force
When liftingo Get a secure grip.
o Use both hands whenever possible.
o Avoid jerking my using smooth, even motions.
o Keep the load as close to the body as possible.
o To the extent feasible use your legs to push up and lift the load, not the upper body or back.
o Do not twist your body. Step to one side or the other to turn.
o Alternate heavy lifting or forceful exertion tasks with less physically demanding tasks.
o Take rest breaks.OSHA Oregon Office of Training and Education
o Inefficient lever
Applied Industrial Ergonomics
o Uneven forces
o Leaky discs
WMSDs
o Unstable structure
Back Disorders
OSHA Oregon Office of Training and Education
Compressive Force Distributions
OSHA Oregon Office of Training and Education
© 2003 Humantech, Inc. Applied Industrial Ergonomics
Back DisordersUnstable structureo Leaky discs
WMSDs
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Spinal Discs Under Various Loads
Normal
loadAdditional
load
Uneven
load
Torsion
load
OSHA Oregon Office of Training and Education
The Forces Involved
The amount of force you place on your back in lifting may surprise you!
Think of your back as a lever.
With the fulcrum in the center, it only takes 10 pounds of pressure to lift a ten pound object.
OSHA Oregon Office of Training and Education
The Forces Involved
If you shift the fulcrum to one side, it takes much more force to lift the same object. Your waist acts like the fulcrum in a lever system, on a 10:1 ratio.
Lifting a 10-pound object puts 100 pounds of pressure on your lower back.
OSHA Oregon Office of Training and Education
The Forces Involved
When you add in the 105 pounds of the average human upper torso, you see that lifting a 10-pound object actually puts 1,150 pounds of pressure on the lower back.
OSHA Oregon Office of Training and Education
The Forces Involved
If you were 25 pounds overweight, it would add an additional 250 pounds of pressure on your back every time you bend over.
OSHA Oregon Office of Training and Education
How to reduce lifting hazards: lift tables, vacuum lift assistance
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Ergonomic Tips to Minimize Force
o Use mechanical lift assists and carts
when available
• Avoid manually handling heavy objects
(more than 35 pounds)
• Avoid carrying objects more than 100 feet
o Practice proper cart handling
• Push instead of pulling
• Use both hands when pushing
• Stand directly behind the cart when
pushing (avoid twisting your body)
• Maintain good control and limit speed
• Ensure cart is not overloaded
OSHA Oregon Office of Training and Education
Ergonomic Tips to Minimize Force
❑ A lift, hoist or other mechanical assistance
is unavailable
❑ The object is heavier than you are capable
of lifting alone (typically more than 35
pounds)
❑ The object is not heavier than what two
people are capable of lifting (typically less
than 60 pounds)
❑ The object is awkward or oversized.
❑ Any object that does not have its weight
equally distributed within the load.
❑ Remember some objects are too heavy
or awkward to be handled with two
people
A Two-Person Lift Is Appropriate When. . .
OSHA Oregon Office of Training and Education
Recurrent Back Injuries
o Back injuries are the most frequent and most costly work related injury
o In Ohio 16% of cases account for 80% of costs
o These are typically second injuries to the back
o We need a method to assess risk of a second back injury given the worker status and job characteristics
OSHA Oregon Office of Training and Education
Static loading and Muscle Blood Usage
Resting Dynamic Static
Blood flowneeded
Bloodflow
supplied
Bloodflow
needed
Bloodflow
needed
Bloodflow
supplied
Bloodflow
supplied
OSHA Oregon Office of Training and Education
Static Loading:
o Avoid prolonged awkward postures
o Change the position of the work or your
body position to get as close as possible
to the work area
o If prolonged awkward postures are
unavoidable, use a “supported” posture
to compensate
o A supported posture uses part of your
body to support the weight of another
body segment that is in an awkward
position
Ergonomic Tips to Minimize Static Loading
OSHA Oregon Office of Training and Education
Ergonomic Tips to Minimize Contact Stress
o Avoid pressure on palms, wrists, and elbows:• Use padding on hard or sharp surfaces
• Change your position to eliminate the stress
o Avoid pressure on knees:• Avoid kneeling on hard surfaces for
prolonged periods
• Use knee pads when kneeling tasks are unavoidable
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Remember OHIO
Only Handle It Once
OSHA Oregon Office of Training and Education
Ergonomics Is a Process, Not a Program.
Applied Industrial Ergonomics
OSHA Oregon Office of Training and Education
Early Reporting of Ergonomic Issues
o Proactive Reporting:• Report suspected ergonomics risk factors to your
supervisor and safety committee representative.
o Early Reporting Process: • Report pain or discomfort associated with work to your
supervisor or other designated person.
o Benefits to Early Reporting:• Leads to early care and quicker healing, preventing
chronic problems.
• Leads to quicker identification of the root cause of the injury.
• Will initiate an ergonomics evaluation by trained personnel.
OSHA Oregon Office of Training and Education
Ergonomic Risk Factors
Repetition
Force
Static Loading
Risk of injury increases with:
o Prolonged exposure to any of these ergonomic risk factors
o Presence of multiple risk factors within a single job task
OSHA Oregon Office of Training and Education
Warm-up/Stretching o Benefits:
• Increases flexibility/elasticity of muscles
• Increases circulation to warm the muscles, improving mental alertness, reducing fatigue
• Decreases muscle tension and stress
o When to Stretch:• Prior to starting your day
• During short breaks (at least once per hour)
• After breaks or lunch to prevent fatigue
• If tension or stress is apparent
• After a lengthy task duration or an extended awkward posture
o The use of stretching is appropriate as part of a comprehensive ergonomic program. Stretching must not be used in place of engineering and or administrative improvements.
OSHA Oregon Office of Training and Education
Summary
o Minimize ergonomic risk factors in your area
o Pay attention to your body and know your physical limitations
o Report ergonomics issues through appropriate channels.
o Ergonomic injuries are preventable, and you own your own safety
OSHA 30 – Ergonomics
OSHA Oregon Office of Training and Education
Discussion/Questions?
References:
1. National Institute for Occupational Safety and Health (NIOSH) Ergonomic Guidelines for
Manual Material Handling
2. Oregon Occupational Safety and Health Administration (OSHA) Construction Ergonomics