This presentation is about the ergonomic design of standing and sitting jobs. Its impacts and what we should and should do. suitable for students and lecturers.
4. Intro
● Ergonomics plays a crucial role in
promoting comfort, productivity,
and overall well-being in the
workplace.
● When it comes to standing and
sitting work, it is important to
maintain a neutral body position to
minimize strain and reduce the
risk of musculoskeletal disorders.
● Here are some key considerations
for both standing and sitting work:
5. “Humans are designed to walk on two
legs, but they are not designed to
stand still”
6. Posture
• Posture refers to the body's average
orientation over time, ensuring balance
and alignment.
• In a neutral posture, the skeleton is in
balance, with joints close to their mid-
point of motion.
• Forward flexed postures, especially
when sitting, can double disc pressure,
increasing lumbar spine stiffness.
• This can cause low back pain and
increase injury risk, especially for manual
tasks like offloading deliveries.
7. Static postures
● Standing or sitting stationary is medically and mechanically
inacceptable because brief periods of walking and large-scale body
movements are necessary for blood return from lower limbs.
● When standing for long durations, people frequently use standing
assistance like a sentry's spear or a herdsman's staff.
● Low back pain is linked to prolonged everyday standing.
● Static work should be avoided and jobs should be changed to provide
relief from static postures in order to prevent health concerns.
11. ● Prolonged sitting for over 95% of
the day is associated with back
pain.
● Many people with bad backs
gravitate towards sedentary work,
and poor design of workstations
causing flexed sitting postures
may exacerbate existing problems
● Professional drivers, pilots, and
operators of machines, such as
forklift trucks, often experience
back pain due to static seated
work
SPINAL PROBLEMS IN SITTING
12. 15%
• Sitting for 8-11 hours per day and more hours
per day increases the risk of mortality by
15% and 40%, respectively
112/147/90%
• Sedentarism is associated with a 112% increased risk of diabetes, 147%
increase in cardiovascular events, 90% increase in cardiovascular
mortality, and 49% increase in all-cause mortality
49%
• Therefore, postural variety and movement
should be designed into jobs to reduce the
risk of mortality
14. Prolonged standing
• Prolonged standing causes physiological changes, including peripheral
pooling of blood, decreased stroke volume, increased heart rate,
diastolic and mean arterial pressure, peripheral resistance, and
thoracic impedance.
• Constrained standing is particularly problematic for older workers or
those with peripheral vascular disease, as the "venous muscle pump"
ceases to function. Fidgeting is a preconscious defense against
postural stresses of constrained standing or sitting, aiming to
redistribute and relieve loading on bones and soft tissues.
15.
16. Musculosceletal problems in standing
• Standing workers often experience low back pain.
• Standing can cause low back pain due to muscular fatigue and excessive trunk
extension, lateral flexion, or twisting
• Excessive lumbar lordosis can stress the soft tissues around the joint, causing
low back pain.
• To avoid this, it is recommended to avoid standing with a pronounced lumbar
lordosis.
• Workspace or task factors that require workers to arch the back greater than
usual should be designed out.
• Poor workstation design can lead to stressful standing postures, causing
spinal problems.
• Constrained standing and older age are associated with increased risk of pain,
highlighting the need for standing workers to have freedom to sit.
20. Standing Aids
Footrest
• In a standing workplace,
workers benefit from a
footrest that supports their
foot, allowing them to stand
with one foot forward and
elevated, reducing lumbo-
pelvic constraint and
promoting plantar flexion.
Compression stockings
• Standing workers are at higher
risk of varicose veins, causing
painful swelling.
• Risk factors include obesity,
smoking, high blood pressure,
and lack of exercise.
• Compression stockings may
reduce leg swelling, but not
significantly.
Toespace
• Toespace is a device
designed to prevent
postural adaptations,
preventing users from
standing further away from
work surfaces due to pelvic
tilting and lumbar flexion,
using pelvis as part of legs.
21.
22. Application of Ergonomics
User
characteristcs
Task demands
Workspace
layout
• Ergonomic workstation design promotes
good posture, with a framework emphasizing
the interaction of three variables.
• Studies show that task demands, workspace
layout, and user characteristics can affect
trunk loading and kinematics.
23. • A person’s working posture is a result of the
requirements of the task, the design of the
workspace, and personal characteristics such
as body size and shape and eyesight.
• Consideration of all three components is
needed in posture analysis and workspace
design.
THE POSTURAL TRIANGLE
24. Factors that Influence Working Posture
User Characteristics
• Age
• Body weight
• Fitness
• Joint mobility
• Existing musculoskeletal
problem
• Previous injury/surgery
• Eyesight
• Handedness
• Obesity
Task Requirements
• Visual requirements
• Manual requirements
• Positional
• Forces
• Cycle times
• Rest periods
• Paced/unpaced work
Workspace design
• Seat dimensions
• Work surface dimensions
• Seat design
• Workspace dimensions
• Headroom
• Legroom
• Footroom
• Privacy
25. 2 3
1
THREE STEPS OF EFFECTIVE WORK STATION
Postural
requirements
Visual
reqiurements
Temporal
requirements
26. ● The neck's posture is determined by
visual requirements, with binocular
overlap occurring 15° either side of the
straight-ahead line of sight.
● This helps avoid static loading of neck
muscles and soft tissues.
Visual Requirements
27. ● Position task objects in convenient
reach for posture and postural load,
and vehicle design's driver's seat
comfort depends on its positioning,
design, and alignment with foot pedals
and manual controls
Postural Requirements
28. ● The workstation design is influenced
by the temporal requirements of
tasks.
● For multiuser computer
workstations, a high bench and stool
may be appropriate, while data entry
jobs require repetitive tasks over the
day.
Temporal Requirements
30. ● The postural requirements for
sedentary work should be met using
modern office chairs with
adjustable backrests, footrests, and
lumbar supports, with task objects
and visual targets placed within
reach and optimal visual field.
31. ● Sedentary workers should position their
main working area directly in front of
their body to minimize twisting of the
spine.
● The twisting mobility of the human back
increases in sitting compared to
standing.
● Jobs involving asymmetric handling of
loads from a seated position, such as
supermarket checkout personnel, are
particularly hazardous
Work Surface Design
32. Seated work Aids
Adjustable
Backrests
• Ergonomically designed
workspaces should be
flexible,
accommodating
multiple postures and a
"designed-in" resting
posture.
Lumbar Support
• Lumbar supports
optimize sitting
postures by providing
space for buttocks to
protrude and tilting the
pelvis forward.
Foot Pump Devices
• A foot pump device
designed to
encourage plantar
flexion can prevent
leg swelling over an
8-hour day. Walking
for 2 minutes every
15 minutes during an
inactive day can also
help prevent leg
swelling.
33.
34. CONCLUSIONS
Ergonomics is crucial in
designing ergonomic
workstations, as it reduces
postural stress and
promotes physical activity.
35. CREDITS: This presentation template was created by Slidesgo,
including icons by Flaticon and infographics & images by Freepik
THANKS!
36. RESOURCES SLIDE
PHOTOS
● Google.com
● R.S.Bridger book
Physiotherapy Icon Pack
VECTOR
● All information is from the R.S.Bridger
Ergonomics 4th edition book
