ERGONOMICS IN SAFETY MANAGEMENT

1. Definition

Ergonomics is the science of designing the workplace, equipment, and tasks to fit the worker — rather than forcing the worker to fit the job.

It aims to optimize the interaction between people, tools and the environment to improve safety, comfort, and performance while reducing injury risk.

2. Objectives of Ergonomics

Prevent musculoskeletal disorders (MSDs).
Improve worker efficiency and comfort.
Reduce fatigue, errors and absenteeism.
Enhance safety, quality and productivity.
Support a sustainable and healthy work environment.

3. Types of Ergonomics

Ergonomics is divided into three main categories:

Type	Focus Area	Examples
A. Physical Ergonomics	Human anatomy, posture, movement and workplace design.	Lifting, pushing, reaching, workstation setup, tool design.
B. Cognitive Ergonomics	Mental workload, perception, memory and decision-making.	Control room design, labeling, alarms, workload management.
C. Organizational Ergonomics	Work systems, policies, communication and scheduling.	Shift rotation, teamwork, job design, workflow efficiency.

4. Ergonomic Hazards

These are workplace conditions that may cause physical or psychological strain.

Category	Example Hazard	Possible Effects
Awkward Posture	Bending, twisting, overhead work	Neck, shoulder, and back pain
Repetitive Motion	Continuous typing, tool use	Carpal tunnel, tendonitis
Forceful Exertion	Heavy lifting, pushing or pulling	Muscle strain, hernia
Static Position	Prolonged sitting or standing	Circulation problems, fatigue
Vibration	Hand tools or heavy vehicles	Nerve or joint damage
Workplace Layout	Poor desk or monitor height	Eye strain, back discomfort
Environmental	Poor lighting, noise, temperature	Stress, errors, fatigue

5. Ergonomic Risk Factors

Poor workstation design.
Repetitive or monotonous tasks.
Inadequate rest breaks.
Poor seating or lighting.
Improper lifting techniques.
Poor job rotation or high work pace.

6. Control Measures for Ergonomic Hazards

A. Engineering Controls (Design-Based)

Adjust workstation height (standing desks, adjustable chairs).
Use mechanical aids (hoists, conveyors, dollies).
Redesign tools for better grip and balance.
Provide anti-vibration gloves and mats.
Optimize lighting and noise levels.

B. Administrative Controls (Work Practice)

Rotate tasks to reduce repetition.
Provide micro-breaks and stretching exercises.
Conduct ergonomic training for proper lifting and posture.
Set work-rest cycles for operators.
Encourage early reporting of discomfort.

C. Personal Protective Equipment (PPE)

Back supports or braces (for lifting jobs).
Anti-fatigue mats (for standing work).
Ergonomic keyboards and mouse devices.

7. Ergonomic Assessment Tools

Tool	Description
REBA (Rapid Entire Body Assessment)	Evaluates full-body posture risk.
RULA (Rapid Upper Limb Assessment)	Focuses on arm, neck, and trunk posture.
NIOSH Lifting Equation	Calculates safe weight limits for manual lifting.
ErgoChecklists / Workstation Checklists	For office and industrial settings.

8. Reliability in Ergonomics

Ergonomic reliability refers to the consistency and dependability of human performance under given conditions.
It connects ergonomics with Human Reliability Analysis (HRA) — ensuring that human error probability is minimized in system design.

Concept	Explanation
Human Reliability	Likelihood that a person performs a required task correctly within a given time.
Relation to Ergonomics	Better ergonomic design → fewer human errors → higher reliability and safety.
Example	Clear labeling, easy-to-reach controls, fatigue reduction → less operational error.

A) Reliability as a Scientific Discipline

Ergonomics is a highly reliable and evidence-based science. Its principles are derived from rigorous research in physiology, biomechanics, psychology, and engineering. When properly applied:

It Produces Consistent, Positive Results: Studies repeatedly show that ergonomic interventions lead to:
- Reduced Injury Rates: Significant decreases in WMSDs like carpal tunnel syndrome and back injuries.
- Improved Productivity: Fewer errors, less wasted time, and higher output.
- Enhanced Quality: Better focus and comfort lead to higher quality work.
- Increased Worker Morale and Job Satisfaction.

B) Reliability in Application (Why It Sometimes "Fails")

The perception that ergonomics is unreliable often stems from poor implementation, not flawed science.

One-Size-Fits-All Approach: A solution that works for one person or task may not work for another. Ergonomics must be tailored.
Improper Diagnosis: Treating a symptom (e.g., providing a wrist rest) without addressing the root cause (e.g., a poorly positioned keyboard and mouse).
Lack of Holistic Approach: Focusing only on physical ergonomics while ignoring cognitive overload or poor organizational culture.
Poor Training: Providing equipment (like an ergonomic chair) without training on how to adjust and use it correctly.
Resistance to Change: Workers or management not adhering to new procedures or using new equipment as intended.

Conclusion on Reliability: Ergonomics as a principle is highly reliable. Its success in practice, however, depends entirely on a systematic approach that involves proper risk assessment, worker participation, and a combination of controls across all three domains (physical, cognitive, and organizational).

9. Benefits of Ergonomic Programs

✅ Reduced injury rates and absenteeism.
✅ Improved worker morale and retention.
✅ Higher efficiency and productivity.
✅ Lower compensation and healthcare costs.
✅ Enhanced compliance with HSE laws.

10. Example — Ergonomic Risk Control in a Power Plant

Job Task	Hazard	Control Measure
Cable pulling	Awkward posture, high force	Use rollers, team lifting, adjustable reels
Control room operator	Static sitting, eye strain	Adjustable chairs, screen height correction, lighting control
Welder	Repetitive motion, vibration	Welding positioners, gloves, rotation
Office staff	Typing, poor posture	Ergonomic desk setup, stretching breaks

safety world

What is ergonomics, its types, hazard control measures and reliability?