Occupational Ergonomics

On this page

Intro to Ergonomics - Work Fit Fundamentals

  • Ergonomics: "Fitting the job to the worker." Goal: optimize human well-being & system performance.
  • Primary Goals:
    • Enhance performance & productivity.
    • Improve safety, reduce injuries/errors.
    • Increase comfort & job satisfaction.
  • Types:
    • Physical: Body mechanics, posture, repetitive tasks, workplace layout.
    • Cognitive: Mental workload, decision-making, human-computer interaction.
    • Organizational: Teamwork, work design, communication, organizational culture.
  • Importance:
    • Prevents Musculoskeletal Disorders (MSDs).
    • ↑ Productivity, ↓ errors & costs.

⭐ The primary goal of ergonomics is to enhance efficiency and well-being by adapting work conditions to suit the capabilities of the worker.

Ergonomic Risk Factors - Strain Triggers

Key physical factors increasing Musculoskeletal Disorder (MSD) risk. 📌 Mnemonic: R.A.F.T.S.

  • Repetition: Performing the same motions frequently or for prolonged periods.
  • Awkward Postures: Deviating from neutral body positions.
    • Neck flexion > 20°
    • Shoulder flexion/abduction > 60°
    • Wrist deviation (ulnar/radial)
    • Sustained trunk flexion or twisting.
  • Force: Amount of physical effort required; can be high or sudden.
  • Time (Static Postures): Holding a posture for a long duration, leading to muscle fatigue.
  • Stress (Contact Stress): Localized pressure from hard surfaces or sharp edges on body parts (e.g., wrists, forearms).

Neutral and awkward wrist postures

  • Other Physical Factors:
    • Vibration: Hand-Arm Vibration (HAVS) from power tools; Whole-Body Vibration (WBV) from driving.
    • Extreme Temperatures: Working in excessive heat or cold.
  • Psychosocial Factors: (Briefly)
    • High job demands, low job control, poor workplace support.

⭐ The most common combination of risk factors leading to MSDs is repetition combined with force and/or awkward posture.

Common Ergo Disorders - Workplace Ailments

Common Work-related Musculoskeletal Disorders (WMSDs):

  • Upper Limb:
    • Carpal Tunnel Syndrome (CTS): Median nerve compression at wrist.
      • Symptoms: Paresthesia (thumb, index, middle, radial ring finger), nocturnal pain.
      • Signs: Tinel's and Phalen's tests have limited diagnostic accuracy; modern diagnosis relies on clinical history, electrodiagnostic studies (nerve conduction/EMG), and imaging. Electrodiagnostic testing and ultrasound for carpal tunnel
    • Tendinitis/Tenosynovitis: Inflammation of tendon/sheath.
      • Examples: De Quervain's (thumb), rotator cuff (shoulder), trigger finger.
    • Epicondylitis:
      • Lateral (Tennis Elbow): Pain at outer elbow.
      • Medial (Golfer's Elbow): Pain at inner elbow.
    • Hand-Arm Vibration Syndrome (HAVS): From vibrating tools; vascular (white finger), neuro, musculoskeletal effects.
  • Back:
    • Low Back Pain (LBP): Most common WMSD; often non-specific.
    • Disc Herniation: Nucleus pulposus protrusion, potential nerve root compression.
  • Neck:
    • Cervicalgia: General neck pain and stiffness.
    • Tension Neck Syndrome: Postural pain/stiffness in neck/shoulders.

⭐ While Phalen's test and Tinel's sign are still used for Carpal Tunnel Syndrome, electrodiagnostic studies provide definitive confirmation and severity assessment.

Prevention & Control - Ergo Solutions

⭐ Engineering controls are the most effective in the hierarchy for ergonomics, aiming to fit the job to the worker.

  • Hierarchy of Controls: Prioritizes interventions. 📌 E.S.E.A.P. (Elimination, Substitution, Engineering, Administrative, PPE).

  • Engineering Controls: Modify tasks, workstation, equipment.

    • Workstation: Adjustable chair/desk height, monitor position (top at/below eye level).
    • Tools: Ergonomic handles, ↓vibration.
  • Administrative Controls: Change work procedures/schedules.

    • Job rotation, work-rest cycles, training on proper techniques.
  • Personal Protective Equipment (PPE): Last resort.

    • E.g., anti-vibration gloves (note limitations).
  • Ergonomic Assessment: Observation, checklists (RULA, REBA), direct measurement.

Correct Sitting Posture for Computer Workstation

High‑Yield Points - ⚡ Biggest Takeaways

  • Occupational Ergonomics: Adapting work to the worker to prevent Musculoskeletal Disorders (MSDs).
  • Common MSDs: Carpal Tunnel Syndrome (CTS), Low Back Pain (LBP), Tendinitis, Tenosynovitis.
  • Major risk factors: Repetitive tasks, awkward postures, forceful exertions, vibration.
  • Prevention hierarchy: Engineering controls (e.g., tool redesign) are most effective, followed by administrative controls.
  • Ergonomic assessment tools include RULA (Rapid Upper Limb Assessment) and REBA (Rapid Entire Body Assessment).
  • Primary goals: Improve worker comfort, safety, efficiency; reduce work-related injuries.

Practice Questions: Occupational Ergonomics

Test your understanding with these related questions

In walking, gravity tends to tilt pelvis and trunk to the unsupported side, the major factor in preventing this unwanted movement is?

1 of 5

Flashcards: Occupational Ergonomics

1/10

Nowadays, patients typically can get chronically exposed to Arsenic in a couple of different situations, including:(1) - _____ smoke(2) - Herbicides used in vineyards(3) - metal smelting

TAP TO REVEAL ANSWER

Nowadays, patients typically can get chronically exposed to Arsenic in a couple of different situations, including:(1) - _____ smoke(2) - Herbicides used in vineyards(3) - metal smelting

cigarette

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial