ergonomics and anatony

7/29/2019 Ergonomics and Anatony

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ERGONOMICS AND ANATOMY



ERGONOMICS-WHAT IS IT ?

The word derived from two Greek words:

“Nomoi” meaning natural laws“Ergon” meaning

work

Hence,

ergonomic s Is the study human capabilities in

relationship to work demands



ERGONOMICS



INTRODUCTION TO ERGONOMICS

The study of interaction between people and machine

and the factors that affect the interaction .Thepurpose is to improve the human machine interaction



WHY IS ERGONOMICS IMPORTANT?

Industries increasingly require higher production

rates and advances in technology to remain competitive

and stay in business. As a result, jobs today can involve

Frequent lifting, carrying, and pushing or pulling loads

without help from other workers or devices

Increasing specialization that requires the worker to

perform only one function or movement for a long period

of time or day after day

Working more than 8 hours a day

Working at a quicker pace of work, such as faster

assembly line speeds and having tighter grips when

using tools



The system can be improved by1. Designing the user interface to make it more

compactable with the task and the user this

makes it easier to use and more resistant to errors

2. Change the work environment to make it safe3. Change the task to make it more compactable

with the user characteristics

4. Change the way the work is organized to

accommodate the people’s needs



EXAMPLES

The work environment can be improved by

eliminating vibration and noise and providing better

seating, better ventilation or lighting

Work organization can be improved by enabling the

workers to work at their own places ,so as to

reduce the psychological stress

in an information processing task we must design

the interface so as to reduce the load on the users

memory



IMPLEMENTATION OF ERGONOMICS IN A SYSTEM

By eliminating aspects of system functioning that

are undesirable uncontrolled or unaccounted such

as

Inefficiency: when worker output produces sub

optimal output

Fatigue: in badly designed people tire

unnecessarily

Accidents injuries and errors: due to bad design

,physical stress and mental stress

User difficulties

Low morale and apathy



FOCUS OF ERGONOMICS

The focus of ergonomics is

on the interaction betweenthe person and the machine



FOCUS OF ERGONOMICS



DESCRIPTION OF HUMAN MACHINE SYSTEM

For ergonomics human is thepart of the system and mustbe fully integrated into thedesign stage so humanrequirements are system

requirements



HUMAN MACHINE SYSTEM

Equipment that is usable and safe

Task that are compatible with the peoples expectations

limitations and training

An environment that is comfortable and appropriate for

the task

A work organization that recognizes the people's social

and economic needs



COMPATIBILITY- MATCHING DEMANDS TO CAPABILITIES

Ergonomic entropy:

this is a disorder in the system functioning that

occurs owing to a lack of compatibility in some or all

of the interaction involving the human operator

The incompatibility can occur due to

Human requirements for optimum system

functioning were never considered at the design

stages

In appropriate task design

Lack of prototyping



APPLICATION OF ERGONOMICS

Applications are mostly in

i) Occupational stress, health hazards.

ii) Management

iii) Design



APPLICATION AREAS SPECIFIC TO OCCUPATIONAL

HEALTH AND SAFETY:

Occupational risk management

Work schedule & sustained performance

Psychosocial approach occupational health

Manual material handling

Work related musculoskeletal disorders

Warning and risk perception

Safe design



APPLICATION IN MANAGEMENT

Work process management, efficiency

Productivity and human resource utilization

Work study and time study

Management of work/rest cycle

Personnel deployment and Shift work

Human cost of work and cost benefit effects for the

modifications done

Manual material handling Work ambient environment monitoring

Human work and efficiency



HUMAN COMPONENTS

Effort

Sense

Central processes

Effort; the three primary effort are the hand,feet,and

voice, more generally the musculoskeletal system and

the body weights can be regarded as effort

Sense: the sense are the means by which we are aware

of our surroundings humans are said to have five

senses

Central process: to carry out activities we need energy

which is provided by the physiological process

providing energy to working muscles. The brain can be

regarded as the information processing unit



M ACHINE COMPONENTS

The machine component include

1. Controlled process

2. Display

3. Controls

4. The immediate environment

5. Work space

6. The physical environment

7. Work organization



Controlled process: the basic operation of the machine e.g.

Nuclear fission, digging vegetable garden, automatically

sorting information

Display: this is the action of the machine or its local

environment. In hazardous systems the human operator has

no direct access to the process and interact with the process

through the displays

Controls: human interact with the machine through controls.controls are also important source of feed back during the

execution of control process

The immediate environment: this is the place in which the

work is carried out and consists of physical work space Work space: the 3D space in which the work is carried out. In

complex systems the work space is fixed



The physical environment: many aspects of physical

environment can affect the worker, ergonomists are most

interested in noise vibration lighting and climate

contamination and pollution of the environment

Work organization: work organization as its most basic

level refers to immediate organization of human machine

interaction, it refers to the organizational structure in which

the work activity is embedded



HISTORY OF ERGONOMICS

In the work environment, the selection and creation of

tools, machines, and work processes continued. Over

centuries, the effectiveness of hammers, axes and

plows improved. With the Industrial Revolution,

machines such as the spinning jenny (a machine that

produced yarn to make cloth) and rolling mills (amethod of flattening iron ore into flat sheets) were

developed to improve work processes. This is the same

motivation behind much of ergonomics today



Wojciech Jastrzebowski created the word ergonomics

in 1857 in a philosophical narrative, "based upon the

truths drawn from the Science of Nature".

In the early 1900's, the production of industry was still

largely dependent on human power/motion and

ergonomic concepts were developing to improve worker

productivity. Scientific Management, a method that

improved worker efficiency by improving the job process,became popular.



Frederick W. Taylor was a pioneer of this approach and evaluated

jobs to determine the "One Best Way" they could be performed. At

Bethlehem Steel, Taylor dramatically increased worker production and

wages in a shoveling task by matching the shovel with the type of

material that was being moved (ashes, coal or ore).

Frank and Lillian Gilbreth made jobs more efficient and less fatiguingthrough time motion analysis and standardizing tools, materials and the

job process. By this approach, the number of motions in bricklaying

was reduced from 18 to 4.5 allowing bricklayers to increase their pace

of laying bricks from 120 to 350 bricks per hour



World War II prompted greater interest in human-

machine interaction as the efficiency of sophisticated

military equipments like airplanes could be compromised

by bad or confusing design. Design concepts of fitting themachine to the size of the soldier and

logical/understandable control buttons evolved.

After World War II, the focus of concern expanded to

include worker safety as well as productivity. Research

began in a variety of areas like Muscle force required to

perform manual tasks, Compressive low back disk forcewhen lifting, Cardiovascular response when performing

heavy labor ,Perceived maximum load that can be

carried, pushed or pulled



ATTEMPTS TO HUMANIZE WORK

In the 1960s in Sweden the VOLVO motor car company

which was suffering from high absenteeism tried to find new

way of assembling cars in an attempt to have more stable

and productive work force there the conventional line

production was replaced by the unit production

The British Quality of working life program in 1980

attempted to combine new approaches job design withtechnological change under the premise



MODERN ERGONOMICS

There are four domains of ergonomics namely;

1. Hardware Ergonomics

2. Environmental Ergonomics

3. Cognitive Ergonomics

4. Macro ergonomics



HARDWARE ERGONOMICS DEALS WITH;

Control design and location parameters and functional

aspects for communication and easy operation

Visual displays, codes, scales and markings

Anatomical and anthropometric (static &dynamic) match

establishment

Working posture, body supportive devices match along

with context fit and workstation

Range of body movement characteristics and thus

limitations of man.



Environmental Ergonomics: Human environment interface

concerning human capabilities and limitations with respect

to the demands imposed by various environmental

modalities and relevant

Cognitive Ergonomics: Human perception and information

processing to reduce error, and system mismatch to

increase usability, functional reliability and safety

(stereotype behavior)

Users' behavioral demands in designing consumer

products

User-centered interface- computer simulation

Effect of psychological stressors on human performance;

etc



MACRO ERGONOMICS

It deals with specific aspects of

Workstation design

Work process design

Work organization

Shift work sitting



FUTURE DIRECTIONS OF ERGONOMICS

Technology push is the main factor influencing thedirections and growth of ergonomics .Rapid development

of usable system a priority in many organizations

In developing countries there is still a need for basic

ergonomic design of factories and offices The future of ergonomics will be strongly dependent on the

ability of Ergonomists to integrate outside our profession

with a range of stakeholders These include universities

and external funding agencies that will support the

education and research programs required to sustain

vitality in the profession



The future for ergonomists will require

development of wide-based skills that include

strong technical and research competencies

This requires a holistic approach to ergonomics to

achieve practical outcomes to the benefit of thestakeholders.

ergonomics and anatony

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