Module 2: Posture and Movement Flashcards
what play a central role in ergonomics?
posture and movement
what provides the force necessary to adopt a posture or make a movement?
muscles
these have an auxiliary functions
ligaments
what allow relative movement of the various parts of the body?
joints
poor posture can lead to what on the muscles, ligaments, and joints?
local mechanical stress
what is principle 1?
joints must be in neutral position
what is principle 2?
keep the work close to the body
what is principle 3?
avoid bending forward
the upper body of an adult weighs about?
40 kg in average
where in the body is the stress particularly large?
lower back
what is principle 4?
a twisted trunk strains the back
what is principle 5?
sudden movements and forces produce peak stresses
what is principle 6?
alternate posture as well as movements
what is principle 7?
limit the duration of any continuous muscular effort
a continuous stress leads to a what?
localized muscle fatigue
it is a state of muscle discomfort and reduced muscle performance
muscle fatigue
what is the relationship of time and muscular effort?
the higher the muscular effort is, the lower time for it to be maintained
what is principle 8?
prevent muscular exhaustion
what is principle 9?
more frequent breaks are better than a single long one
what is principle 10?
limit the energy expenditure in a task
how many energy does a prolonged task without experiencing any general fatigue is demanded of the task?
< 250W
what activities demand less than 250W?
writing, typing, ironing, light walk
what is principle 11?
rest is necessary after heavy tasks
what is principle 12?
take account of differences in body sizes
what is principle 13?
use the anthropometric tables appropriate for specific populations
what is imposed by the task or workplace?
posture
what is principle 14?
select a basic posture that fits the job
what has a number of advantages compared to standing?
sitting
what is principle 15?
alternate sitting with standing and walking
what is principle 16?
the height of the seat and back rest of the chair must be adjustable
what is principle 17?
provide proper seating instructions
what is principle 18?
specific chair characteristics are determined by the task
what is principle 19?
the work height depends on the task
what is principle 20?
the height of the work surface, seat, and feet must be compatible
what is principle 21?
use a footrest if the work height is fixed
what is principle 22?
avoid excessive reaches
what radius should all things considered used daily in most operations be?
approx. 50 cm
where should workpieces be placed?
in front of or near the body
what is principle 23?
select a sloping work surface for reading tasks
what degrees does the position of work surface for reading purposes?
45 degrees
what degrees does the position of work surface for writing purposes?
15 degrees
what is principle 24?
allow sufficient legroom
what is the width clearance for the table?
60 cm
what is the required depth clearance for the table at the knees and feet?
at the knees = 40cm
at the feet = 100cm
what is the required thickness of a writing surface of the table?
<= 3cm
TRUE OR FALSE
Activities where considerable forces must be exerted or frequently changed should be carried out in a standing position
True
what is principle 25?
alternate standing with sitting and walking
what is principle 26?
the work height depends on the task
what is principle 27?
the height of the work table must be adjustable
what is principle 28?
do not use platforms
what is principle 29?
provide sufficient room for the legs and feet
what is principle 30?
avoid excessive reaches
what is principle 31?
select a sloping work surface for reading tasks
these techniques relate to the provision of a varied task package
change of posture
what is principle 32?
offer variation in tasks and activities
what is principle 33?
introduce sit-stand work stations
what is principle 34?
alternate sitting postures
what is principle 35?
make occasional use of a pedestal stool in standing work
TRUE OR FALSE
Working for long periods with the hand and arm in a good posture can lead to specific complaints of the wrist, elbow, and shoulder
False = POOR posture
what ailment is a local inflammation of a tendon attachment due to a combination of a bent elbow and bent wrist?
tennis elbow
what play a role in the development and aggravation of application of a force and repetitive movement?
repetitive strain injuries (RSI)
what is principle 36?
select the right model of tool
what is principle 37?
do not bend the wrist, use curved tools instead
what is principle 38?
hand-held tools must not be too heavy
what is principle 39?
maintain your tools
what kg should a tool weigh?
< 2kg
what is principle 40?
pay attention to the shape of handgrips
the handgrip must have a diameter of aprox. ___ and length of approx. ____?
diameter = 3cm
length = 10cm
should you use pre-shaped handgrips?
no, the fingers will be constrained
what is principle 41?
avoid carrying tasks above shoulder level
what is principle 42?
avoid working with the hands behind the body
this can be stressful in the energetic sense for the muscles, heart, and lungs as some of these can cause high, localized mechanical stresses that can lead to body aches and pains
movements
what is still frequently needed in spite of mechanization and automation?
manual lifting
this is seen as a major cause of lower back complaints
lifting
what is principle 43?
restrict the number of tasks which require displacing loads manually