Ergo1.1 Flashcards
Human + Machine
Ergonomics
A scientific discipline concerned with the understanding of interaction among humans and other elements of a system, and the professions that applies that theory, principles, data, and methods to design, in order to optimise human well-being and overall system performance
Ergonomics
Ergonomics is the scientific study and body of knowledge of ____, ____, and ____ for appropriate design of living and work environments.
human abilities, limitation, characteristics
Ergonomics come from the Greek word
ergon- work/effort
nomos- natural law/ study of
T/F Developed into a recognized field during World War II, when for the first time, technology and the human sciences were systematically applied in a coordinated manner
True
T/F Interest in the approach grew rapidly, especially in Europe and in the U.S. leading to the foundation in England of the first-ever national ergonomics society in 1950, which is when the term ergonomics was adopted.
False 1949
Traditional emerged from a military background. Preferred term in the U.S. and several other countries
Human Factors
Focuses on the safety and comfort of workers. More prevalent in Europe and the rest of the world.
Ergonomics
Ergonomics draws knowledge from
human sciences and technology
Concerned with human anatomy, and some of the anthropometric, physiological, and biomechanical characteristics as they relate to physical activity.
Physical Ergonomics
Concerned with mental processes, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system
Cognitive Ergonomics
Concerned with the optimization of socio-technical systems, including their structure, policies, and processes.
Organizational Ergonomics
Anatomy + Physiology:_____
Psychology: _____
Ergonomics 1: Physical Ergonomics
Ergonomics 2: Cognitive Ergonomics
The scientific study of the structure of organisms including their system, organs, and tissues.
Anatomy
The scientific study of how the human body functions. This includes the mechanical, physical, bioelectrical, and biomechanical functions.
Physiology
The scientific study of the way the human mind works and how it influences behavior, or the influence of a particular person’s character on his or her own behavior
Psychology
Benefits of Human Factor and Ergonomics
- Reducing human error in the system performance
- Reducing hazards to individuals in the work environment
- Improving system efficiency
- Design a system with user focus
- Improve quality of life
Why Human factors and Ergonomics
- Economic advantages
- Progress in knowledge and technology
- Moral imperative
Ergonomics is
- Human-Centered
- Multi-disciplinary
- Application Oriented
The science of measurement and the art of application that establishes the physical geometry, mass properties, and strength capabilities of human body.
Anthropometry
Where did the word Anthropometry come from
Anthropos - human
Metrikos - measurement
Anthropometric considerations
- sizes
. proportions - mobility
- strengths
- other factors that define human being physically
Basis of Measurement
- Baseline Definition
- Postures
Anthropometric Design Principles
- Design for all
- Design for adjustment
- Design for several sizes
- Design for extreme individuals
The human body is normally composed of how many bones
206
Connective Tissues
- Muscles
- Tendons
- Ligaments
- Cartilage
Body links that determine the human mobility
Joints
The spine consists of how many vertebras
24
The maximal tension or force that a muscle can develop voluntarily between its origin and insertion
Muscle Strength
Force or torque that can be applied by a body segment to an object external to the body.
Body Segment Strength
It is infuenced by motivation and the physical condition under which it is exerted.
Strength
Body strength is measured by what instrument.
Analog or Digital Dy-nanometer
It plays a central role in ergonomic
Posture and Movement
It is involved in adopting a posture carrying out a movement and applying.
muscles, ligaments, joints
It provides the force necessary to adopt a posture or make a movement
Muscles
It has an auxiliary function
Ligaments
It allows the relative movement of the various parts of the body-
Joints
T/F Poor posture and movement can lead to local mechanical stress on the muscles, ligaments, and joints, resulting in complaints of the neck, back, shoulder, wrist, and other parts of the Respiratory system.
False (Musculoskeletal)
A number of principles of importance to the ergonomics of posture and movement derive from a range of specialist fields, ______, ______, and _______.
Biomechanics, Physiology, Anthropometry.
When maintaining a posture or making a movement, the joints ought to be kept as far as possible in a _______.
Neutral Position
The muscles are able to deliver their _______ when the joints are in the neutral position
Greatest force
T/F Raised arms, bent wrists, bent necks, and turned heads, bent and twisted trunks are examples of poor postures where the joints are not in a neutral position
True
If the work is too far from the body, the arms will be _____, and the trunk bent over forwards.
Outstretched
The upper part of the body of an adult weighs about ______ on average.
40 kg
The stress is particular in the _______.
Lower back
Twisted postures of the trunk cause undesirable stress to the _____.
Spine
The majority of the population can carry out a prolonged task without experiencing any general fatigue provided the energy demand of the task __________.
does not exceed 250W
The reduction in activity must be such that the average energy demand over the working day _______________.
does not exceed 250W
The position of the hands as well as the focal point are also of great importance to the posture of ____, ___, and ____.
head, trunk, and arms
Work Height
Use of eyes: frequent,
Use of hands/arms: infrequent
10-30 cm below eye height
Work Height
Use of eyes: frequent,
Use of hands/arms: frequent
0-15 cm above elbow height
Work Height
Use of eyes: infrequent,
Use of hands/arms: frequent
0-30 cm below elbow height
The most important operation should take place within a radius of approximately ______.
50 cm
For reading purposes, the position of the work surfaces which is viewed must be titled by at least _______
45 degree
The required depth clearance must be _____ at the _______ and _______ at the _______, which should allow the user to sit close to the work without bending the trunk forward.
at least 40 cm; knees
at least 100 cm; feet
A table meant for standing work which is used for a given task, and on which no objects of different thickness are used, must have an adjustment range of _______ in order to cater for individual differences in body size.
at least 25 cm
A pedestal stool can be used once in a while to vary a standing work posture. A pedestal stool consist of a seat which is adjustable in height (65-85 cm) and is tilted forward between __________.
15 and 30 degrees
Another ailment is _______, which is a local inflammation of a tendon attachment due to a combination of a bent elbows and bent wrist.
tennis elbow
If the tool cannot rest on a surface, and is normally used with one hand, its weight should not ________.
exceed 2 kg.
If the whole hand is used to exert a force, the handgrip must have a diameter of approximately ____ and a length of approximately _____.
3 cm
10 cm
Human Factor traditionally emerged from a military background and concentrated on ________.
Human Performance
Ergonomics focuses on the ____ and _____ of worker
safety and comfort
______ workplaces, equipment, and the physical environment to fit the characteristics and capabilities of most people in a complex task
To design
Poorly designed equipment or environment may lead to _____.
injuries
T/F Anatomy is the science of measurement and the art of application that establishes the physical geometry, mass properties, and strength capabilities of the human body
False (Anthropometry)
Anthropometric measures
- Static (Structural Dimension)
- Dynamic (Functional Dimension
T/F Studies have been done in other American countries, most of which are industry-specific.
False (Asian countries)
Organs that generate force and movement
Muscles
_______ are strong elastic tissues connecting muscles around joints
Tendons
It connects bones and provides capsules around joints.
Ligaments
It is translucent. viscoelastic, flexible material, as articulation surfaces at the joints
Cartilage
Maximal displacement of the body defines the ___________.
range of motion
Applications of Engineering Anthropometry
Automotive Vehicle Interior
Airplane Cockpits
Aircraft Passenger Accommodation
Computer Workstation Furniture
It is a discipline that seeks to adapt the job to the worker with the goal of promoting worker health, safety, comfort, and productivity.
Occupational Ergonomics
Muscle, nerve, and tendon pain caused by repetitive movement and overuse. It can also be called Cumulative Trauma Disorder and Repetitive Motion Injury.
Repetitive Strain Injury (RSI)
Risk factors associated with RSI
- Physical Factors
- Psychological/Organizational Factors
- Environmental Factors
Factors like force, posture, frequency/duration of work associated with the likelihood of developing an RSI because they stress our joints, muscles.
Physical Factors
Stress is an indirect player because it is not stress that causes injury-it is the physical reaction of our bodies to stress that can cause or aggravate RSI.
What Factor is this
Psychological/Organizational Factors
______ that ,ay contribute to the development of RSI are noise, temperature, and lighting.
Environmental Factors
Causes of RSI
- Repetitive movements
- Repeated exposure to ergonomic stress factors over a period of time
- Compression on hard and sharp edges
- Forceful exertion
- Sustained or awkward body posture
Types of RSI
- Tendon Disorder
- Nerve Disorder (Carpal Tunnel Syndrome)
- Neurovascular Disorder (Neck and Shoulder disorder)
Sample of Tendon Disorder
- Tendinitis
- Tenosynovitis
- Trigger Finger
Causes
- Excessive repetition
- Task that require shoulder to be elevated
- Overuse
- Overexertion
Symptoms
- Dull, aching sensation at the joint
- Discomfort from certain movements
- Tenderness to the touch
Tendon Disorder
Cause
- Repetitive wrist motions
- Poor wrist posture
Symptoms
- Pain
Numbness
Nerve Disorder
Causes
- Frequent reaching above shoulder level
- Lifting object with the shoulder drawn down and back
Symptoms
- Numbness in the finger and hands
- The arms may also feel as if they are going to sleep
Neurovascular Disorder
Injuries and disorders that affect the human body’s movement or musculoskeletal system (i.e. muscles, tendons, ligament, nerves, discs, blood vessel, etc)
Musculoskeletal Disorder(MSDs)
Group of painful disorder of muscles, tendons, and nerves
Work Related Musculoskeletal Disorder
Three Primary Ergonomics Risk Factors
- High Task Repetition
- Forceful Exertion
- Repetitive or Sustained Awkward Posture
When other risk factors are present work-related physical stress and high task repetition contribute to MSD formation. A repetitive job has a cycle time ____________.
30 second or less
Many work tasks require high force loads on the human body. Muscle effort increases in response to high force requirements, increasing associated fatigue which can lead to MSD
Forceful Exertion
Risk of MSD is increased when joints are worked outside of this mid-range repetitively or for sustained periods of time without adequate recovery time.
Repetitive or Sustained Awkward Postures.
Individual Risk Factors Include:
- Poor work practices
- Poor overall health habitats
- Poor rest and recovery
- Poor nutrition fitness and hydration
Workers who use poor practices, body mechanics, and lifting techniques increase MSDs risk factors. Widespread poor practices increase their physical stress and hamper their body’s ability to fully recover.
Poor work practices
People who are overnight, have a bad diet, or are frequent smokers or drinkers face a higher risk of suffering from both musculoskeletal issues and a host of other chronic diseases.
Poor overall health habits
Fatigue outpaces the workers’ recovery system, causing a musculoskeletal imbalance. Workers who don’t get enough rest and recovery put themselves at risk.
Poor rest and recovery
Workers who do not take care of their bodies are putting themselves at a higher risk of developing musculoskeletal and chronic health problems.
Poor nutrition, fitness and hydration.
Disorder associated with peripheral nervous system, which includes nerves and ganglia located outside the spinal cord and brain. It is the compression of the median nerve at the wrist, which may result in numbness, tingling weakness, or muscle atrophy in the hand and fingers.
Carpal Tunnel Syndrome (CTS)
It is the study of forces on the human
Biomechanics
Two major application of biomechanics
- Improve human movement
- Treatment or prevention of injury
Major part of biomechanics
- Kinematic
- Kinetics
Examines how, when, and where a body moves
Kinematics
Examines the causes of motion, the internal and external forces that cause motion or remain at rest
Kinetics
It is defined as maintaining proper musculoskeletal positioning during movement.
Body Mechanics
This refer to the sum of biochemical reactions that occurs in the cell of a living organism to do the following:
- Provide energy for vital processes and activities
- Assimilate new organic material into the body
Metabolism
The common measure of energy used is _____, and the corresponding measure for energy rate is _____.
- kcal
-kcal/min
Types of Metabolism
- Basal metabolism
- Activity metabolism
- Digestive metabolism
The minimum amount of energy when it is resting. Energy use only in vital circulatory and respiratory function. resting human in a warm location at least 12 hours after eating
Basal metabolism
It is the energy associated with physical activity such as sports and manual work.
Activity metabolism
It is the energy used for digestion
Digestive metabolism
- 4 kcal/kg
- Primary source of energy
- converted to Glucose (C6H12O6) and glycogen
Carbohydrate
- 4 kcal/kg
- converted to amino acid
Protein
- 9 kcal/kg
- converted to fatty acid
Lipids
Basal metabolism depends on the following:
- Age
- Heredity
- Gender
- Weight
- Percentage of Body Fat
Standard Basal Metabolic rate
Male 20 years old
- BMRh/kg = 1.0kcal/hr per kg of body weight
Female
- BMRh/kg = 0.9kcal/hr per kg of body weight
As a person ages, the basal metabolism rate declines slowly, so the age correction is simply to ______ from the preceding values for each decade above 20 years
subtract 2%
This is the difference between in the amount of oxygen needed by the muscles during muscular activity and the amount that is supplied.
Oxygen debt
______ is anaerobic during this time lag before the body can respond to increase the need for oxygen.
Glycolysis
T/F Many office injuries are caused by the repetitive tasks that put strain on our muscles and joints.
TRUE
_______ to your body
What think is it?
Listen
Think Detection
Practicing good work_____ and ____ergonomics at work.
What think is it?
habits
applying
Think Prevention
________ our body through proper diet and regular exercise.
What think is it?
Strengthen
Think Activity
As strong as this system might be, overuse of muscles through repeated movements can put stress on your body, causing a____________.
RSI/ Repetitive Strain Injury
Other names of RSI
Cumulative Trauma Disorder/Repetitive Motion Injury
T/F RSIs are the least common type of injury found in the office
FALSE (most common)
Remember to always speak to your supervisor if you are experiencing pain at work.
Think Detection: Symptoms and Stages of Injury
It is closely associated with the development of office related injuries are _______, _______, and _________. Some factors have a more direct influence on these injuries than others.
Risk Factors
Physical, Psychological, and Environmental factors
Factors such as ____, ____, _____ are associated with the likelihood of developing an office related injury because they stress our joints and muscles.
force, posture, and frequency/duration of work
It is debated as having the most direct influence on the development if these injuries.
Physical Factor
Sometimes employees are overloaded that is, they feel they cannot do something
because they do not have enough time or the right resources. This causes employees to
stress about their ability to perform their tasks well. Decreasing workload and minimizing
the need for overtime can alleviate stress
Cognitive (Mental) Effort
An employee’s perception of how well co-workers interact, how work is organized and how
often he or she is supervised can be a source of stress. Lack of job clarity and general job
dissatisfaction can also stress employees.
Psychosocial
When we are stressed, we tend to tense up certain muscles and pay little attention to proper
posture and movement. Stress, therefore, is an indirect player because it is not the stress that
causes injury it’s our bodies’ physical reaction to stress that can cause or aggravate an injury.
Psychological/Organizational Factors
Varying work schedules, such as shift work, can affect a worker’s sleep and eating patterns,
as well as his or her family and social interaction. Stress and poor health habits can
increase the likelihood of injury at the office. Also, when employees work overtime, they are
exposed to longer hours of repetitive tasks, which may increase the chance of injury.
Organizational
Some ___________ may contribute to the possibility of developing an injury while others simply reduce
productivity.
Environmental Factors
3 Samples of Environmental Factors
Noise
Temperature
Lighting
Ergonomics can be defined as the ________________________, not forcing the
worker’s body to fit the job.
science of designing the job to fit the worker
T/F Acknowledge the warning signs as late as possible and do something about it.
False (Early)
