30 ERGONOMIC TASK ANALYSIS AND RISK ASSESSMENT AT WORK PLACE

Geetha Suresh

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Objective of the Module:

 

1.  To understand the concept of ergonomics and its importance in work place

2. To know about the relationship between Man, Machine and environment.

3. The student should be able to understand the risk factors at work place and the importance of ergonomics in task assessment.

 

Introduction to the Module:

 

Dear students,

 

The Study of ergonomics and risk assessment at the workplace is an interesting topic for designers. Let me start with the most quoted ergonomics advice to designers and students and then go ahead with the theoretical explanation of the content.

 

 

“Every good Project starts with a task analysis and ends with a User trail”.

 

What do you understand by this?

 

Here the task analysis refers to formal or semi-formal attempt to state what the user is going to do with the product/service or the environment.

 

The second half of the statement deals with User trail is an experimental investigation where the sample of people tests a prototype version of the product under controlled condition.

 

To understand this task analysis, user trail and other terminologies, we need to first understand the meaning of ergonomics.

 

1.0 Introduction to Ergonomics:

 

Ergonomics is the word coined from Greek, “Ergo”means “work”and “Noms”mean “natural laws”. The study of Ergonomics is a multidisciplinary with a combination of Physiology, Anatomy, medicine with Physiology, engineering and psychology combined.

 

1.1 Meaning of Ergonomics:

 

The Science involved in designing of the workplace is known as the Ergonomic process. A designer while working on the workplace process, should keep in mind the capabilities and limitations of the worker, workplace space and the employer setbacks. The systematic ergonomics plan in the improvement of designing the workplace will remove the risk factors involved at productivity level.

 

1.2 Goal of Ergonomics:

 

There are three goals which the discipline of ergonomics addresses when dealing with the analysis, design and management of man-made systems.

  • Safety
  • Comfort
  • Well – being

 

To achieve this goal, we need to understand the three most crucial elements of ergonomics. Man (the worker), Machine (the work) and Environment (the workplace).

 

 

1.3 Ergonomic Triangle:

 

1.      Man (The Worker) – Every individual has his/ her own limitations with the body characteristics. Using few criteria, these qualities can be assessed:

    a.       Anthropometric dimensions.

b.      Body composition and

c.       Physiological and Psychological fitness.

 

These assessment helps in understanding the human capabilities and limitations while assigning tasks. The mismatch between the capabilities and work nature leads to serious risk factors in terms of physical and mental problems.

 

2.    Machine (The Work)

 

The Physical work leads to fatigue and tiredness whereas the mental and automation work leads to more stress related issues. Both physical and mental work are to be assessed for the risk factors like postural positions, design of tools and equipments.

 

3.    Environment (The Work Place)

 

The environment or the work place is one of the most important source responsible for stress originating. The Physical factors like heat, ventilation, lighting, noise level, thermal comfort and psycho – social factors relating to interpersonal relationship.

 

1.4 Criteria for Task Analysis:

 

The factors considered for effective task are:

  •  Functional efficiency (as measured by productivity, task, performance etc.,)
  • Ease of use
  • Comfort
  • Health and Safety
  • Quality of working life

2.0 What is an Ergonomics Assessment?

 

Ergonomic assessment referred to workers capacity and workplace study. It ensures that a worker’s workstation is ergonomically designed to maximize productivity with minimal risk injury.

 

2.1 Understanding Ergonomics at Work:

 

As it’s understood that, Ergonomic science is to design work tasks to fit the worker’s capabilities and limitations of the human body. It is the moral responsibility of the employer to provide a safe work environment free from hazards and ergonomic risk factors for his employees.

 

Ergonomic problems result in productivity, efficiency, quality, and safety problems. Jobs and tasks that are frustrating, uncomfortable, or inefficient are typically not ergonomically correct.

 

Ergonomic improvements result in productivity, quality, and safety improvements. An effective ergonomic improvement process seeks to identify and eliminate any deterrent to maximum work capacity, and limit worker fatigue and discomfort while improving process efficiency and productivity.

 

2.2 Principles of ergonomics in the workplace include the following:

  •  Identifying correct postures for tasks (keeping in mind the lower back, neck, shoulder, wrists, hips and feet). This includes trying to maintain neutral postures of joints where possible.
  • Eliminating strenuous tasks where possible including heavy lifting, forceful movements, twisting (e.g. using machinery where possible)
  • Taking rest breaks from repetitive tasks
  •  Identifying risks within the workplace (including educating staff to independently identify risks and avoid these postures)

 

2.3Ergonomic factors to be considered at workplace:

  •  Fatigue and Poor anthropometric fit as main contributing factors that help to reduce performance effectiveness.
  • Ideal seating is one in which the sitter loses all awareness of the seat and the sitting posture.

Benefits of implementing good ergonomics in the workplace:

 

A well-designed workplace can result in better outcomes for your workers and puts less strain on their health and safety. Whilst a poor design can result in injury to workers and be less work efficient. Some benefits include:

  • Can reduce the cost of work-related injuries
  • Can increase productivity
  •  Can reduce time spent off work
  • Your employees know that you have their best interest in mind
  • Allowing employees to be able to independently identify risks and implement appropriate strategies and techniques

 

3.0 Ergonomic Risk Factors:

 

Risk factors related to work activity and ergonomics can make it more difficult to maintain this balance, and increase the probability that some individuals may develop a musculo-skeletal diseases (MSD).When assessing the workplace for ergonomic risk, 3 things are usually targeted for elimination, and reduction where elimination is not possible. They are:

  • High Task Repetition
  • Forceful Exertion
  • Sustained Awkward /Poor Posture

These 3 factors directly lead to muscle fatigue or strain, leaving the body open to injuries.

 

3.1. High Task Repetition:

 

Even when something is easy and seem relatively effortless to do once or twice, it can be a strain on the body when it should be done many times over a short period of time without rest. For example, while working on harmless activities like using the computer mouse or typing on a keyboard in awkward angle. The same style of innocuous factor is observed in factory assembly line productions where same motion is used again and again.

 

A job is put into the factor of elevated risk repetition, when the cycle time is in 30 seconds or within 30 seconds. Majority of factory tasks and cycles are repetitive in nature, and need to be frequently controlled by hourly or daily production targets and work processes.

 

High task repetition combined with other factors like forceful action or awkward postures, can contribute to the formation of MSD.

 

The formation of MSD is the balance between local soft tissue fatigue and ability of an individual’s recovery from fatigue. The excessive fatigue could be controlled by getting adequate supply of blood to the of soft tissue and this supply of blood flow maintains to perform work of soft tissues and helps in sustained metabolic balance.

 

3. 2. Forceful Exertion:

 

Lifting of heavy loads in manual work to vigorous efforts in pushing or twisting involving the whole body or smaller body part like the wrist when turning a heavy knob or lever all involves force. These work task force needs high force loads on the individual body, which results in increased muscle efforts and lead to fatigue and muscle related problems.

 

The musculoskeletal disorders do not occur only due to one activity, it could be the combination of forceful exertion done repeatedly. For example, perhaps turning the dial doesn’t require too forceful an exertion but when done repetitively, the injuries happen.

 

3. 3. Repetitive/Sustained Awkward Postures:

 

Sustained poor posture is the most common risk factor and perhaps the best well-known. Awkward postures place excessive force on joints and overload the muscles and tendons around the effected joint. Joints of the body are most efficient when they operate closest to the mid-range motion of the joint. Risk of MSD is elevated when joints are worked outside this mid-range cyclically or for sustained periods of time without adequate recovery time.

 

3. 4 What can be done to minimize these ergonomic risk factors?

 

1)  Identifying them is the first step.

2)Then a job redesign or environment adjustments have to be made to minimize or eliminate these risks. Exercises to build better strength and stamina and learning to take the necessary rest break to recover from muscle fatigue.

3) Eliminate or reduce awkward postures with ergonomic modifications.

4) Maintain joint range of motion to accomplish work tasks within the mid-range of motion positions for vulnerable joints.

5) Proper ergonomic tools should be utilized that allow workers to maintain optimal joint positions.

6) Job rotation and job task enlargement is a way to reduce repeated and sustained awkward postures that can lead to MSD.

7) Providing safe & effective procedures for completing work tasks can reduce MSD risk.

8)Removing excessive force and awkward posture requirements will reduce a worker’s fatigue and permit high recurrence tasks to be performed without a substantial increase in musculo-skeletal risk for most of the workers.

9)Using mechanical assists, counter balance systems, adjustable height lift tables and workstations, powered equipment and ergonomic tools will reduce work effort and muscle exertions.

10)  Workers should be trained to use proper lifting and work techniques to reduce force requirements.

11)  Risk reduction techniques Job rotation

12)    Cross train workers so they can rotate jobs throughout the day.

13)  Change tasks often within your own job (Example: type for an hour and then file for an hour).

14)  Break each job up into smaller or different tasks.

15)  Determine the risk factors for each task.

16)  Determine how each task affects risk factors for the total job. Select appropriate tools by attaching a handle extension, bending can be eliminated from many jobs. Participatory ergonomics

17)  Enlist workers to brainstorm better ways to do their work.

18)  Have trained workers teach new staff. Ergonomics training

19)  Educate staff on the risk factors for musculoskeletal disorders, and how ergonomics can make their work easier, more efficient, and safer.

20)  Train staff to identify job tasks that may present a risk and determine better ways to complete those tasks.

 

4.0 Good Ergonomics = Good Economics:

 

Effective injury prevention is both an art and a science. Systematically recognizing and controlling ergonomic risk factors is an important part of your company’s commitment to providing a safe place of work for all team members.

 

4.1 Advantages of good ergonomics:

  • Lower injury rates and MSD incidences.
  • Reduction in human costs associated with MSDs.
  • Reduction in company direct and indirect costs associated with MSDs.
  • Improved worker safety.
  • Increased worker comfort.
  •  Reduced worker fatigue.
  •  Increased productivity from making jobs easier and more comfortable for workers.
  • Improved product quality.
  • Increased savings
  • Fewer injuries
  • More productive and sustainable employees
  • Fewer workers’ compensation claims –Fewer employees experiencing pain • Implementing ergonomic improvements can reduce the risk factors that lead to discomfort. Increased productivity
  • Ergonomic improvements can reduce the primary risk factors for MSDs, so workers are more efficient, productive, and have greater job satisfaction.
  • Increased morale • Attention to ergonomics can make employees feel valued because they know their employer is making their workplace safer.
  • Reduced absenteeism
  • Ergonomics leads to healthy and pain-free workers who are more likely to be engaged and productive.

 

4.2 Poor ergonomics:

  • ‘trigger finger’:

This condition results from the inflammation of tendons and/or the tendon sheaths located in the fingers. Repetitive movements or using one’s grip too strongly or too often can make it difficult to move one’s fingers without experiencing sharp pain.

  • Ganglion cysts:

Ganglion cysts are very hard, pea- or larger- sized lumps which develop on joints or in tendon sheaths. They are commonly found on the wrist, the back of the hand or the base of fingers. Symptoms range from discomfort to pain. Ganglion cysts can come and go, though sometimes, they remain, causing pain if they pinch a nerve. Sufferers can opt to have a ganglion cyst removed surgically, yet there is no guarantee that they will not return.

  • Musculoskeletal disorders (MSDs):

 

These are debilitating, painful conditions affecting muscles, tendons, tendon sheaths and nerves. One of the most oft-cited MSDs is carpal tunnel syndrome (CTS), a condition in which a nerve within a specific passageway in the wrist is pinched, causing an array of symptoms ranging from unpleasant to painful. These include numbness, tingling and sharp pain. In serious cases, CTS can affect mobility and even cause partial paralysis. Another common MSD is tendonitis: the inflammation or irritation of tendons, often caused by incorrect posture. Tendonitis tends to occur in injury-prone areas like the wrists, kneecap, elbow and wrist. A closely related injury is bursitis: the inflammation of the bursa (a sac-like cavity between the bone and tendon, or skin and bone). Bursitis can cause pain and swelling in the knee, elbow or shoulder. It is tends to arise from frequent kneeling, repetitive movements of the shoulder and pressure to the elbow.

  • Back injuries:

The nature of your profession often determines your risk of suffering from painful back injuries. Some of the highest risk employees are those working in the health care profession. Nurses, for instance, or those who care for the ill or elderly, tend to bend from the waist continually and lift or move patients with more weight than their body can bear. Those in the construction sector are likewise particularly vulnerable, as are those who work in the food sector lifting heavy boxes and carrying heavy trays. The range of movements that can cause back problems is ample and includes twisting the waist while lifting items and lifting items from below the knees or over the shoulders.

 

Ø  It can affect you in ways you least expect; merely sitting or standing for long periods of time, for instance, can cause cumulative trauma, as can adopting the wrong posture while working on your computer.

 

  • Headaches & Migraines:

 

Working for too many hours with the wrong lighting can cause headaches; if the light on your computer screen or in the room itself is too bright or dim, it can also cause everything from itching, burning and fatigue in the eyes seemingly unrelated symptoms to like indigestion, nausea and even blurred or double vision. Poor posture is a big factor in migraine and headache sufferers due to it causing active trigger points in your neck and shoulder that refer directly to the head.

 

  •   A Stiff Neck:

 

More often than not, we tend to attribute severe pain in the neck and immobility in the neck area, to a bad sleeping position; we are often surprised to learn that the cause can commonly be attributed to actions undertaken during our waking hours. If you keep your neck in a rigid position for too long, you will more than likely suffer the consequences in your neck area.

 

5.0 Summary:

 

The ergonomic study in work environment is the most important study of the current trend. Ergonomics plays a vital role in building a culture of safety, health, and wellness. The Physical and Psychological factors that affects the individual workers, their work place and the immediate environment have direct and indirect effect on the efficiency and productivity output. So, it’s important that every employer should give utmost consideration to the work place. Studies have shown a corresponding relationship between good ergonomics and improved product quality. On the other hand, poor ergonomics leads to frustrated and fatigued workers that don’t do their best work. Reduced absences where workers will be less likely to take time off to recover from muscle soreness, fatigue, and MSD-related problems. Prevention is a shared responsibility. When workers see that the company is serious about eradicating the ergonomic risk factors in the workplace, workers morality will be improved. Thus, this results in the employers addressing the MSD risk factors under their control.

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