Industrial Ergonomics

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Industrial Ergonomics
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Session Objectives

• You will be able to
• Understand the principles of ergonomics
• Recognize the risk factors, signs, and symptoms
  of musculoskeletal disorders (MSDs)
• Understand our program for identifying,
  reporting, and controlling MSDs
• Know how to protect yourself from MSD injuries
  and reduce your risk

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What Is Ergonomics?

• Modify jobs to fit capabilities of people
• Reduce MSDs
• Repetitive reaching, forceful exertions, bending
  and lifting, or working with vibrating equipment
• Engineering controls
• Safe work practices
• PPE

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Musculoskeletal Disorder (MSD) Injuries

• 1.8 million MSD injuries each year
• 600,000 MSD injuries require time away from work

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OSHA Regulation of Ergonomics

• General Duty Clause
• Applies to unregulated hazards
• Failure to keep a hazard-free workplace
• Hazard recognized by employer or employers
  industry
• Hazard could cause death or serious harm
• Method existed to correct the hazard exists

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What Are MSDs?

• Injuries to
• Muscles
• Nerves
• Tendonstendinitis
• Ligaments
• Joints
• Spinal discs

Image Credit National Institutes of Health/NIAMS
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MSD Characteristics

• Occur from a single event or many small injuries
• Take weeks, months, or years to develop
• Produce no symptoms in early stages, but show
  symptoms after permanent injury has occurred
• Contributing causes may occur at home and at work
• Same MSD may differ in severity from person to
  person doing a similar task

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General Signs of MSDs

• Less strength for gripping
• Less range of motion
• Loss of muscle function
• Inability to do everyday tasks

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MSD Symptoms

• Back and neck shooting pain, stiffness
• Shoulderspain, stiffness, loss of mobility
• Arms and legs shooting pains, numbness
• Elbow and knee jointspain, swelling, stiffness

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MSD Symptoms (cont.)

• Hands and wrists swelling, numb, loss of
  strength
• Fingersjerking movements, or loss of strength,
  mobility, and feeling
• Thumbspain at the base
• Feet and toesnumb, stiff, burning sensation

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Outward Signs of MSDs

• Swelling or inflammation of joints
• Vigorously shaking hands
• Massaging hands, wrists, or arms
• Cradling arms
• Limping
• Stiff back

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Common MSDs

• Carpal tunnel syndrome
• Low back pain
• Eye strain
• tendinitis
• Trigger finger

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Common MSDs (cont.)

• De Quervains diseaseforceful grip
• Carpet layers kneecontact trauma
• Rotator cuff tendinitis repetitive motion
• Herniated disc bending and twisting
• Raynauds phenomenonexcess vibration

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Act on the Signs of MSD

• Act immediately
• Report the problem
• Seek medical attention
• Early treatment and intervention can prevent
  permanent injury

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MSDs Related to Risk Factors

• DeQuervains Diseaseforceful grip
• Trigger Fingercontact stress
• Rotator Cuff Syndromerepetition
• Thoracic Outlet Syndromeposture
• Raynauds Syndromevibration

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Risk Factors that Lead to MSDs

• Repetitive motions
• Fixed / awkward postures
• Vibration
• Force
• Contact stress
• Twisting / bending
• Elevation of elbows
• Lifting

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Risk FactorRepetitive Motion

• Stress on muscles and tendons
• Contributing factors
• Duration and speed of repetitious movement
• Number of musclesinvolved
• Required force
• Raising and lowering the arm over and over again

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Awkward Postures

• Stress on muscles and tendons
• Contributing factors
• Reaching overhead
• Force the body must maintain to hold the position
• Holding fixed positions (static loading)
• Lifting while twisting, reaching, or turning

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Vibration

• Affects tendons, muscles, joints, nerves
• Contributing factors
• Prolonged grip
• Restricts blood supply to hands and fingers
• Tools without vibration dampening device
• Poor power tool maintenance
• Prolonged use of a grinder

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Forceful Exertions

• Inflammation of tendons, nerves, joints
• Contributing factors
• Type of grip
• Weight of object
• Body posture
• Type and duration of the task
• Repeatedly turning a screwdriver while pushing at
  the same time

Image Credit OSHA
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Contact Stress

• Pressing against or grabbing a hard object puts
  pressure on nerves, tendons, and blood vessels
• Contributing factors
• Repetition
• Duration of contact
• Grip strength required
• Wresting wrists on the keyboard while typing

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Lifting

• Improper lifting caused by failure to
• Size up the load
• Bend your knees
• Do not twist
• Clear path
• Lower slowly
• Push carts/dollies
• Team lifting

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Workplace risk factors

• Inappropriate tools
• Continuous contact
• Restricted clearance
• Improper seating/support
• Bad body mechanics
• Inadjustable equipment

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Management/employee involvementAudit work
stations Audit procedures

• Management/employee involvement
• Audit work stations
• Audit procedures

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Engineering controls

• Preferred method
• Work station design
• Tool design
• Equipment design

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Work station design

• Provide adequate
• Work space
• Work height
• Support
• Storage space
• Machine controls

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Work station design

• Reduce static loading
• Raise / lower working height
• Remove hard / sharp edges
• Provide mechanical advantages
• Insulate heat / cold

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Work station redesign

• Provide seating / support
• Improve material orientation
• Improve layout

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Tool selection should minimize

• Awkward, bent grip
• Vibration
• Excessive grip strength
• Awkward positions to exert force
• Repetitive motions

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Administrative controls

• Job rotation
• Shift length
• Overtime management
• Rest breaks
• Production rates

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Work practice controls

• Use proper techniques
• Avoid unnecessary steps
• Job training
• Exercise/ conditioning

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Ergonomics Management

• Job assessment
• MSD reporting and response system
• Designated coordinator
• MSD intervention and control system
• Training
• Encourage employee participation and reporting of
  MSDs

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Identifying and Controlling MSD Hazards

• Determine whether MSD hazards exist and degree
  of risk
• Devise a control strategy with your input
• Implement control measures
• Training

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Control Methods

• Install engineering controls including
  workstation layout and proper tools
• Institute work practice controls including
  neutral postures for performing tasks
• Administrative controls including rescheduling to
  reduce frequency or duration of exposure to MSDs
• Personal protective equipment (PPE) to provide a
  protective barrier between worker and MSD

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How to Protect Yourself

• Change positions often, take stretch breaks
• Maintain neutral posture whenever possible
• Eliminate or reduce MSD risk factors
• Use material handling aids
• Report MSD symptoms

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Key Points to Remember

• Recognize MSD signs and symptoms
• Understand MSD hazards
• Take steps to control MSD hazards
• Report MSDs
• Participate in the Ergonomics Program