INSY 3020 Test #1 2019
mechanical human-machine system
(semiautomatic) power provided by machine, but controlled my the human
What has happened involving HF during the 2010s?
"new" looks at "old" technologies (cars, phones, TVs)
what is vibration syndrome also known as
"white finger"
goals of workstation/place/area design
-optimize use of energy and thus maximize productivity -avoid musculoskeletal problems -enhance safety -enhance comfort key issue = adjustability
major principles of fitting the work to the worker
1. know your user population (anthropometry) 2. visual ergonomics impacts physical ergonomics (eye strain) 3. neutral postures and relaxed muscles (awkward posture) 4. static vs. dynamic postures- Micro-breaks (movement is your friend) 5. all ergonomics are local (ergonomics is personal, user preferences are important)
How many principle body systems are there?
11
how much of the us working population has suffered one or more MSD
15
What percentage of the body's metabolism do the muscles use?
50%
How should machines be to fit to the largest percentage of consumers?
5th percentile with light clothes and the 95th percentile with heavy clothes
Where should heart rate be at rest?
65-85 BPM
What percentage of the weight does the back support when standing upright
70-80%
When standing straight how much does the human back support
70-80% of body weight
type of ergo injury that includes repetitive motion injuries and overuse syndrome
Cumulative Trauma Disorders (CTDs)
What are the 3 types of ergonomic injuries?
Cumulative Trauma Disorders, acute/traumatic injuries, and HF incidents
Principles of work design
-determine work surface height by elbow height -adjust the work surface height based on the task being performed -provide a comfortable chair for the seated operator -provide adjustability in the seat......etc
inputs needed for DUET
-force estimates for each task - number of repetitions for each task -estimate of cumulative damage for each task -cumulative damage for each task summed for "daily dose"
MMH task risk factors
-weight of load -location -frequency -stability -coupling
inputs needed for LiFFT task anaylsis
-weight of the load -peak horizontal from hip to center of load during the lift -number of repetitions for this task per day
What should a person's max heart rate be?
220-(age) BPM
What are the 4 types of modeling biomechanics?
2D static 3D static dynamic (2D, limited 3D) special purpose (lower back, wrist, hand)
Give an example from South Ogden, Utah of human reliability/ingenuity.
3 pilots used coffee, soda, and the contents of their bladders to land after their hydraulic fluid leaked out
How many muscles are in the body?
400
What percentage of TBW do muscles make up?
50%
Example uses of Work Physiology
Can the job be safely accomplished by people? ... for the required duration using prescribed tools and methods? Which methods are easiest (i.e., takes less energy)?Can a specific individual perform a job safely? How should jobs be ranked (for compensation & fatigue avoidance/work-rest cycle purposes)?
Who were the "founders" of IE?
Frank and Lillian Gilbreth
"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself." Who said this and where?
George Bernard Shaw in "Man and Superman"
what accounts for nearly 1/3rd of lost time injuries
MSD
What is an example of standardization?
QWERTY keyboard
what is fatigue failure
a process of progressive structural damage that occurs when a material is subjected to cyclic loading
Phototropism
a tendency to turn toward bright lights
What was suggested as a "good" definition for safety?
elimination of all hazards
T/F: When you exert a force, there is an equal and opposite force acting on only your external structure.
false, force is acted on your internal and external structures
T/F: Anthropometry only includes measurements of height, weight, and lengths of body parts.
false, it includes arm reach and other measurements
What's an example of modality compatibility?
fire alarm (audible and visible alarm)
What are the 5 impacting factors of anthropometry?
gender ethnic origin age generation/time obesity
The endocrine system controls hormones that regulate activities such as?
growth development reproduction metabolism fluid balance blood homeostasis coping with stress
manual human-machine system
hand tools and other aids where the human is the power source
mismatches result in
injury
What is the first goal of work physiology?
insure the worker can perform tasks efficiently and safely within the environment
11 principle body systems
integumentary, skeletal, muscular, cardiovascular, lymphatic, nervous, endocrine, respiratory, digestive, urinary, reproductive
What's an example of movement compatibility?
joy stick (up goes up, down goes down)
What happens when a product appears less dangerous than it actually is?
less likely to read warning labels
What happened involving HF during the 80s-90s?
more growth, computers, disasters, litigation
Does anyone "own" safety?
no
How are weights and heights distributed over the entire human population?
normal distribution
What's homeostasis?
normalize, stay the same
Where should heart rate be to maintain moderately heavy work?
not consistently above 120-150 BPM
What do cognitive risk factors result in?
not disabling injuries, but can result in total system loss
what are some examples of administrative controls
reduce task frequency; rotate workers; alternate hands; have gradual break-in periods; train workers
HF physical design errors
result in confusing and difficult to understand systems (lack of feedback, poor visibility, poor mapping)
Which is the most efficient lever? Why?
second, fulcrum at the bottom
Types of Muscle tissue
skeletal, smooth, cardiac
this part of the body is the most injured, accounting for 36% of MSD cases
the trunk
T/F females have a significantly higher MSD rate?
true
What is the best comparison to a second class lever?
wheelbarrow
what does engineering controls focus on?
work environment such as tools and equipment
What are used to achieve efficiency and safety goals when work includes moderate to heavy components?
work-rest cycles
type of ergo injury resulting from poor human/machine environment ("oops wrong button")
HF incidents aka system failures
What 3 areas are covered in this course?
Industrial Ergo, HF Engineering, Occupational Safety
What were some of the HF disasters of the 80s and 90s?
TMI, Bhopal, Chernobyl, Challenger/Columbia, Elections
cotton twisters hand
VDT disease
human-machine systems (Sanders and McCormick)
a combination of one or more human beings and one or more physical components interacting to bring about, from given inputs, some desired output
what are the three things needed for each task when estimating risk with FF
a measure of force (stress, force, moment) for the task; number of cycles for that task; an S-N curve for the material in question
What happens when the "cost of compliance" is high?
ability to heed warnings decreases
What is the secondary goal of work physiology?
accurately measure and evaluate the amount of energy needed to perform the job
type of ergo injury that deals with sudden injuries such as slips, falls, or tool slippage
acute strains, sprains, and pulls and traumatic injuries
What is the target population for work physiology?
all people
anthropometric data (includes more than just length and weight)
anatomical limits of movement, limits of reach, static body dimensions, static force capabilities, endurance capabilities
study of human body measurements especially on a comparative basis
anthropometry (Merriam Webster's)
part of anthropology having to do with measurements of the human body to determine different races and individuals
anthropometry (Webster's)
the measurement of the sizes and proportions of the human body
anthropometry (dictionary.com)
biomechanics
application of mechanical principles in the study of living organisms
What 3 things does biomechanics combine?
biology anatomy mechanics
What is the ultimate goal of ergo/HF?
build better products and systems
how can you increase your back suport by 6 times
by bending at the waist
how is engineering control achieved
by redesigning tools, workstations, and jobs
thoracic outlet syndrome
caused by compression of nerves and blood vessels between neck and shoulder
What are the two general types of fatigue?
central (nerves) and peripheral (muscles)
What are the two ways of classifying systems?
closed/open loop and parallel/series
What are the 2 functions of the nervous system?
communication network controls functions to maintain homeostasis
system (from Sanders and McCormick)
composed of humans, machines, and other things that work together (interact) to accomplish some goal which these same components could not produce independently
What kinds of problems does poor communication (labels, signage, instructions) lead to?
confusion delays errors, scrap, wasted product, spills injuries dissatisfied employees and customers
What is safety?
control of hazards to an acceptable level
What are some examples of contact stresses?
corners, edges, handles
model for self-healing biological tissue
damage - healing
What are the 5 general effects of aging?
decline starts age 30 progressive loss of muscle mass lost muscle tissue replaced by fat decrease on maximal strength diminishing of muscles reflexes
telegraphists cramp
degenerative joint diseases
How should work be designed to avoid fatigue?
design work for light to moderate energy expenditure
What do physical ergo risk factors result in?
disabling injuries, but generally not death or total system loss
Uses of anthropometric data
dynamic dimensions are a function of the interaction of body parts, we need more static than dynamic, limited methods for converting static to dynamic
What happened involving HF during the 2000s?
emphasis on usability and marketing products
What 3 ways do we use work physiology?
enhance efficiency avoid fatigue ensure safety
system
entity that exists to carry out some purpose
What is the basic distinction between human factors and ergo?
ergo focuses on the physical/mechanical, while HF focuses on the cognitive/mental
Of "human factors engineering" and "ergonomics," which is the European term from the time when they were considered synonyms?
ergonomics
focuses on the physical and mechanical
ergonomics
multidisciplinary activity that brings together info on people's mental and physical capacities and applies that info in designing jobs, processes, products, workplaces, and equipment
ergonomics
focuses on human beings and their interaction with products, equipment, facilities, procedures, and environments used in work and everyday living
ergonomics and human factors engineering
two ways to prevent CTDS
establish ergonomics program and institute controls
T/F previous ergonomics have been based on fatigue failure theory
false
T/F: HF is just common sense.
false
T/F: HF is mainly applying checklists and guidelines.
false
T/F: Military anthropometry can be used to represent civilian data because it is more available.
false
T/F: There is no overlap between physical and cognitive factors.
false
What is the difference between a feature and a procedure?
feature is set in place (airbags), while a procedure is something you have to do (seatbelt)
What is the advantage of third class levers?
flexibility
what are some factors for physical risk-CTDS
force, repetition, non-neutral work postures, vibration exposure
Give an example of a first class lever on your body.
head bending at the waist
What is used to evaluate energy usage?
heart rate (and less commonly oxygen uptake)
What are some examples of environmental risk factors?
heat, cold, vibration, stress (mental and emotional), contact stresses
10 risk contributors to neurovascular diseases?
high frequency (repetition) of the task; high forcefulness of exertion; awkward postures; duration of the task; mechanical pressure; vibration; exposure to cold; lack of rest; obesity; psychosocial factors (job insecurity)
What is the body's inherent response to stress?
homeostasis
focuses on the cognitive concerns, such as control/display relationships
human factors
What are the 4 parts of the urinary system?
kidneys ureters bladder urethra
Give an example of a third class lever on your body.
lifting a ball with your arm (bisep)
What 4 things does peripheral fatigue entail?
loss of action potential impairment of transmission accumulation of lactic acid oxygen debt in skeletal muscle
What 4 things does central fatigue entail?
loss of motivation and personal effort neuromuscular "recruitment" is minimized decrease in voluntary motor drive (lose output) psychosocial issues
Which is more reliable: machines or humans?
machines
What are the 3 types of human-machine systems?
manual, mechanical, automated
What are the 4 ways of collecting anthropometric data?
mechanically (tapes, scales, calipers) photographically mock-up simulation computerized/automated methods
efficiency
monitoring energy expenditure and avoiding excess fatigue
What is expected to happen involving HF during the 2020s?
more advances with augmented reality and autonomous systems
What are the 3 types of natural mapping (compatibilities)?
movement, spatial, modality
What are the functions of the muscular system?
movement/posture circulation blood pressure food movement heat production breathing expelling of waste products
What 4 body systems are most relevant to work physiology?
muscular cardiovascular respiratory nervous
what kind of disorders include nerves and adjacent blood vessels
neurovascular disorders
what type of employees have higher injury rates than veterans
newer employees
When designing things, should you use yourself as a model?
no
Are ergo and human factors only concerned with humans interacting with their work environment?
no, work and everyday living
What kind of environment is used for work physiology?
not optimal and not controlled (with noise heat, vibrations, and stress)
In regards to energy expenditure, what is safety?
not pushing people beyond their physical limitations
What were the lessons learned about HF from WWII?
organizations, space race, and laboratories
stitchers wrist
osteoarthroses
carpenters elbow
overuse injuries
What are the 4 ways to measure heart rate?
palpation electronics light sound
What is the key concept of anthropometry?
percentiles (95th, means taller than 95% of population)
Give some examples of personal characteristics.
physical condition height/weight/size(anthropometry age gender diet non-work activities (hobbies/recreation) medical history (illnesses, disabilities) medications, drug use new and inexperiences employee high personal stress level
Give an example from WWII of human reliability/ingenuity.
pilots urinated into their planes hydraulic reservoir
A sand-colored shovel is an example of
poor visibility and failure to consider operational environment
examples of engineering control?
position the work and worker to eliminate awkward postures; make workstations and seats adjustable; angling or titling; use fixtures; parts within easy reach
Give an example of a second class lever on your body.
pressure on the ball of your foot
What interactions with human beings do ergo and human factors focus on?
products, equipment, facilities, procedures, environments
What is the most important priority of ergo/HF?
protect user health/sanity
Name some ergo/HF priorities
protect user health/sanity improve productivity, quality, and satisfaction avoid unnecessary costs, delays, and hassles reduce waste and scrap sell more products build better products and systems
What are the 2 functions of the urinary system?
purification of blood and maintains fluid, electrolyte and pH balance and removes toxins
What happened involving HF during the 60s-80s?
rapid growth, expansion beyond military and space
What are the 2 ways the nervous system is a communication network?
receives info and interprets formulates responses to send to organs
HF procedural design errors
result in non-optimal performance (poor communication, lack of enforcement, high cost of compliance)
automated human-machine system
robots, programmed controlled machinery, where human interaction is required to install, program, reprogram, maintain, alter, and adjust
Give an example of a failure in HF visibility.
sand-colored shovel
What are computerized/automated methods of measurements now being used for?
security
What is the best comparison to a first class lever?
seesaw (fulcrum in the middle)
What 4 components that serve functions make up systems?
sensing (info receiving) info storage info processing/decision action functions
What is the best approach for dealing with variable dimensions in workplace design?
simulate the task with workers of opposite extremes of measurements to identify problems
What are the 3 types of muscle tissue?
skeletal cardiac smooth
integumentary system
skin
What are the two types of anthropometric data?
static and dynamic
What's an example of spatial compatibility?
stove controls for which burner
cumulative damage assessment (Palmgren-Miner Rule)
sum of (cycles experienced/cycles to failure)
what are some common tendon disorders?
tendinitis; tenosynovitis; ganglionic cyst; tennis elbow; golfers elbow
what are some common work injuries
tendon disorders, nerve disorders, and neuromuscular disorders
what causes carpel tunnel syndrome
the compression of the median nerve by swollen tendon sheath, inside carpal tunnel
What is the biggest problem to ergo when it comes to anthropometry?
the population is getting increasingly heavier and older
all progress depends on...
the unreasonable man (woman)
What happens when people are more familiar with a product?
they are more confident in their ability to safely handle it
what can cause nerve disorders?
they occur when nerves are exposed to pressure from hand, sharp edges of work surfaces, tools, or nearby bones, ligaments, or tendons-7
Why are environmental factors and personal characteristics often overlooked?
they're not visible manipulations of actions that a worker must "do" to perform a job
Which is the least efficient type of lever? Why?
third class, fulcrum is toward the body with the load extended
What is a "cost of compliance?" example
time required to read all warnings vs changing the light bulb
What is the goal of design? (R. Buckminster Fuller)
to make the world work in the shortest possible time through spontaneous cooperation without ecological offense or the disadvantage of anyone
What are the functions of the lymphatic system?
transport clean fluids back to the blood drains excess fluids from tissues removes debris from cells of the body transports fats from the digestive system
what are the top three high risk occupations for MSDs?
transportation and material moving; production; healthcare
A human factors system can be as simple as a human using a hammer to drive nails or as complex as a crew docking a space craft at the International Space Station.
true
Musculoskeletal disorders ("ergonomic"injuries) are typically thought of as resulting from cumulative exposures. However, Dr. Sesek argued that sudden traumatic events (e.g., "wrong tool"accidents) should also be considered "ergonomic"injuries.
true
T/F You should virtually always be able to trace a system failure to a HF-related root cause.
true
T/F: Environmental conditions can act to magnify BOTH physical and cognitive risk factors.
true
T/F: Generally, people really want to follow instructions.
true
T/F: OSE is both an art and a science.
true
T/F: Some stressors affect both physical and cognitive performance.
true
T/F: There is no standard format for anthropometry measurements.
true
What was happening with HF during the WWII era?
use of tests for selecting proper people for jobs and the development of improved training methods
the lifting fatigue failure tool (LiFFT)
used to assess risk of manual lifting tasks
the shoulder tool
used to assess the risk of shoulder injuries
the distal upper extremity tool (DUET)
used to assess the risk of upper extremity CTDs
proper work-surface height is a function of both the _____ and the _______ being performed
user, task
What is another name for overexertion trauma?
volitional
What controls the muscular system?
voluntary nervous system (somatic nervous system)
What happens with too many warnings?
warning overload
What is the advantage humans have over machines?
we can for inferences, hypotheses, and react in novel ways to changing inputs
bricklayers' shoulder
wear and tear disorders