Ergonomics
ERGONOMICS AND EFFICIENT WORK DESIGN
Mike Dixon, PhD
In the continuous quest for operational excellence and waste reduction, ergonomics plays a pivotal role in enhancing productivity and safeguarding employee well-being. Ergonomics, the science of designing work environments to fit the capabilities and limitations of workers, directly addresses motion waste by optimizing tasks and workspaces for efficiency and safety. This reading explores how ergonomics contributes to reducing motion waste and delves into the principles of designing tasks and workspaces that promote efficiency, prevent injuries, and improve overall job satisfaction.
Introduction to Ergonomics
Definition and Importance of Ergonomics in the Workplace
Ergonomics, derived from the Greek words “ergon” (work) and “nomos” (law), is the scientific discipline concerned with understanding the interactions between humans and other elements of a system. In the workplace, ergonomics focuses on designing or modifying work to fit the worker, rather than forcing the worker to fit the work. This involves considering the physical capabilities and limitations of employees to ensure that tasks, equipment, information, and the environment suit each worker.
The importance of ergonomics in the workplace cannot be overstated. Proper ergonomic design can prevent repetitive strain injuries and musculoskeletal disorders, which can develop over time and lead to long-term disability. By enhancing comfort and reducing physical strain, ergonomics contributes to improved productivity, quality of work, and employee satisfaction.
The Relationship Between Ergonomics, Motion Waste, and Standardized Work
Ergonomics is intrinsically linked to motion waste and standardized work. By applying ergonomic principles, organizations can minimize unnecessary movements (motion waste) that do not add value to the product or service. Ergonomics complements standardized work by ensuring that the standardized processes are not only efficient but also safe and sustainable for employees.
Standardized work defines the most efficient method to perform a task, and ergonomics ensures that this method aligns with human capabilities. Together, they create a harmonious work environment where efficiency does not compromise employee health, and safety does not hinder productivity.
Principles of Ergonomic Work Design
Implementing ergonomic principles in work design involves understanding how the human body interacts with the physical aspects of the workplace. The following key principles guide the creation of work environments that support efficiency and safety.
Neutral Body Postures
Designing Tasks to Keep Joints Naturally Aligned
Neutral body posture refers to a comfortable working position where the joints are naturally aligned, reducing stress on muscles, tendons, and skeletal structures. In this posture, the spine is aligned, shoulders are relaxed, elbows are at the side, wrists are straight, and knees are slightly bent.
Minimizing Strain on Muscles and Joints
Designing tasks to maintain neutral postures minimizes the strain on the body. This can be achieved by adjusting the height of work surfaces, positioning tools and materials within easy reach, and providing adjustable chairs or stools. For example, when assembling small parts, a workbench at the appropriate height prevents the worker from bending over, reducing back strain.
Minimizing Excessive Movements
Reducing Unnecessary Bending, Reaching, and Twisting
Excessive movements such as bending, reaching, and twisting place additional stress on the body and contribute to fatigue and injuries. Ergonomic work design aims to minimize these movements by:
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- Adjusting Workstations: Positioning work surfaces and equipment at optimal heights and angles.
- Organizing Layouts: Arranging tools and materials so that workers can access them without excessive movements.
- Mechanical Aids: Using equipment like lift tables, conveyors, or adjustable shelves to reduce manual handling.
For instance, placing frequently used tools on a pegboard directly in front of the worker at shoulder height can eliminate the need for reaching or bending.
Proper Tool and Equipment Placement
Positioning Frequently Used Items Within Easy Reach
Tools and materials that are used frequently should be within the primary work zoneāan area within easy reach without the need to stretch or lean. This reduces the physical effort required and the time spent retrieving items. The use of extendable arms or sliding shelves can aid in bringing items closer to the worker.
Organizing Tools to Match the Sequence of Tasks
Arranging tools and materials in the order in which they are used supports an efficient workflow and minimizes unnecessary motions. This principle ensures that as the worker progresses through the task, the required tools are readily available, eliminating pauses and movements to search for items.
An example is a surgeon’s tray in an operating room, where instruments are laid out in the order they will be used, allowing smooth transitions between steps.
Ergonomic Risk Factors
Identifying and addressing ergonomic risk factors is essential to prevent injuries and improve efficiency. The main risk factors include:
- Repetitive Motions
Performing the same motion repeatedly over prolonged periods can lead to fatigue and overuse injuries such as tendinitis or carpal tunnel syndrome. Tasks should be designed to allow for variability in movements, and where possible, automation can reduce the need for repetitive manual actions.
2. Forceful Exertions
Tasks that require significant physical effort, such as lifting heavy objects or applying force to tools, increase the risk of injury. Ergonomic solutions include mechanical lifting aids, power tools, or redesigning the task to reduce the required force.
3. Awkward Postures
Working in non-neutral postures, such as reaching overhead, bending forward, or twisting the torso, places strain on the body. Adjusting work heights, angles, and positions can help workers maintain neutral postures.
4. Contact Stress
Contact stress occurs when a hard or sharp object presses into soft tissues, such as leaning against a hard edge or gripping tools with narrow handles. Padding, rounded edges, and ergonomically designed tools can alleviate contact stress.
5. Environmental Factors
Environmental conditions such as poor lighting, excessive noise, and extreme temperatures can impact comfort and safety.
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- Lighting: Adequate lighting reduces eye strain and helps maintain alertness.
- Noise: High noise levels can cause stress and impede communication.
- Temperature: Extreme heat or cold affects comfort and can reduce manual dexterity.
- Chairs: Should provide lumbar support, adjustable seat height, and swivel functionality.
- Keyboards and Mice: Ergonomic designs reduce strain on wrists and hands.
- Anti-Fatigue Mats: For standing workstations, mats can reduce leg and back fatigue.
- Lighting: Adequate illumination prevents squinting and leaning forward to see better . Adjustable task lighting allows workers to position the light where needed.
- Glare Reduction: Using matte finishes, screen filters, and proper positioning of monitors can reduce glare.
- Monitor Placement: Screens should be at eye level and at a comfortable viewing distance to prevent neck strain.
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- Identify any ergonomic risk factors present.
- How do these risk factors contribute to motion waste or employee discomfort?
- What ergonomic interventions could be implemented to address these issues?
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- How might ergonomic principles be applied differently in manufacturing versus office environments?
- What unique challenges might arise in implementing ergonomics in various settings?
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- Why is it important to involve employees in ergonomic assessments and solutions?
- How can organizations encourage employee engagement in ergonomics
Self-Assessment Questions
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- Explain the Relationship Between Ergonomics and Motion Waste
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- How does applying ergonomic principles help reduce unnecessary movements?
2. List and Describe Three Ergonomic Risk Factors
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- Provide examples of each and how they might be mitigated.
3. How Do Proper Tool and Equipment Placement Improve Efficiency?
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- Explain the importance of positioning frequently used items within easy reach.
4. What Are the Benefits of Adjustability in Workstations?
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- Discuss how adjustable equipment accommodates individual workers and enhances comfort.
5. Describe the Impact of Ergonomics on Employee Health
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- How does ergonomics contribute to the prevention of musculoskeletal disorders and improve job satisfaction?