Lecture 11: Occupational Ergonomics

Question 1

WMSD stats

Answer 1

work related muscoloskeletal disorders occurred in 2007 at 35 per 10,000 workers, 29% of all injuries

nursing and orderlies had the highest IR

Question 2

definition of ergonomics

Answer 2

relating workplace conditions to the capabilities of the worker

designing the workplace to better suit the worker, reduces injuries and illness, and leads to higher productivity and higher job satisfaction

Question 3

Ergonomic approaches

Answer 3

cognitive: match mental information processing with capabilities to minimize human error
physical: assure physical demands do not exceed limits, work physiology and biomechanics
maintenance tasks: enough space, incorporate tools,

Question 4

Common causes of human error (that would required cognitive ergonomic improvement)

Answer 4

failure to percieve hazardous condition
failure in information-processing or decision-making
failure in motor actions following correct decisions

Question 5

Define work physiology

Answer 5

Localized muscle fatigue (associated with high intensity, highly repetitive work)
Dynamic work and whole-body fatigue (large muscle groups contract and relax a lot)

Question 6

Biomechanics

Answer 6

concerned with properties of tissues and its response to mechanical stresses.

Overexertion injury risk factors: repetitiveness, forceful exertion, awkward postures, local mechanical contact stress, vibration, temperature extremes

Question 7

Anthropometry

Answer 7

measurement of human individual for purposes of understanding human physical variation

better workstations and tools based on analysis of human interaction

Question 8

Biomechanical Analysis, what are the approaches?

Answer 8

methods to systematically analyze work situations and predict maximum static and dynamic loads

Approach:

1) Work methods analysis: critical recording of every step in the performance of a given task, broken into sequence. identify risky parts (time activity log, video recording)
2) Check Lists: niosh lifting equation

Question 9

NIOSH lifting equation, and RWL, and LI

Answer 9

uses frequency of event and coupling multiplier to come up with a recommended weight limit for what someone could perform over an 8 hour period without increased risk of low back pain (LBP)

lifting index = load weight / RWL. if its > 1 then you need an administrative control to reduce number of events pe day

Question 10

Office Ergonomics: risks for upper limbs, lower back, upper back neck head

Answer 10

typical physical stresses: repetitive motions (typing, mouse), awkward postures, leading to cumulative trauma disorders, repetitive strain injuries

upper limb risk factors: repetition, static posture, lack of rest
- leads to: tendonitis, carpal tunnel syndrome, tenosynovitis

lower back risk factors: prolonged seating, poor workstation design
- leads to: disk problems, muscle strain

upper back neck head risks: poor monitor position, poor layout of workspace, hand held telephone, poor seating
- leads to: spinal damage, fatigue, nerve compression

Question 11

Workstation design

Answer 11

• put frequently used items in better reach
• keep things at eye level
• better keyboard design
• open work surface

OSHA recommends: frequent breaks (15min/2hrs, stretching regime during breaks