L7: Assessment of manual tasks in industry Flashcards
What is an occupational health physio?
- An exciting career pathway with many directions
- Clinical physiotherapist merging musculoskeletal skills into occupational environments
- Injury and case management
- Occupational health and safety
- Policy
- Clinical scope of work
- Injury management: worksite assessments, return to work planning, functional capacity exams, work hardening programs, physiotherapy treatment
- Injury prevention focus: risk assessments, task analysis, training, ergonomic assessments, health and well being programs, early intervention physiotherapy
- Prevention is better than cure
- Onsite physiotherapy or consulting
What is ergonomics?
Ergonomics is the scientific study of human work
‘Work’ can be used in its broadest or narrowest sense
Greek ergon (work) + nomos (law) focusses on the study of work performance with an emphasis on worker safety and productivity
What are 3 scopes of ergonomics?
What is the scope of ergonomics (direct and indirect effects)?
Why is ergonomics important?
- People define themselves by work
- Need to understand what is happening in the work place
- Between ¼ to 1/3 of our time is spent at work
- Work health and safety legislation states workplace must provide a safe and healthy work environment
Is work good for us?
- Work can expose us to dangers
- For some workers they are at greater risk of harm when at work, compared to not being at work
In general, good, meaningful work is better for health than not working, but we need to consider the nature and quality of work
_______ are the most common workplace injury as ergonomics is important.
Musculoskeletal disorders
What are 3 significant impacts of musculoskeletal disorders as the most common workplace injury?
- Individual
- Workplace
- Productivity on company
- Society
- Burden on healthcare system
What are causes of MSD’s?
What are 3 most common mechanisms of injury for MSD’s?
- Slips / Trips / Falls
- Hit by an object
- Manual tasks
What is the definition of manual task?
A task that requires a person to lift, lower, push, pull, carry or otherwise move, hold or restrain any person animal or thing = life
Different feedback throughout the day
What are 5 risks of hazardous manual task?
EXAM QUESTION
When a job or task involves one or more of the following
- Repetitive or sustained force
- High or sudden force
- Repetitive movement
- Sustained and/or awkward posture
- Exposure to vibration
Often there are 2 or more risk factors present
What are some examples of hazardous manual tasks?
What is a repetitive force?
Using force repeatedly over a period of time to move or support an object
Repeated more than twice a minute
What is a sustained force?
Occurs when force is applied continually over a period of time
Held for more than 30 seconds at a time
What is a high force?
Jerky or unexpected movements while handling an
item
Tasks where force is applied suddenly and with speed to generate high force
- Eg. patient slips and falls –> needs to be able react
What is a high force?
Where a worker finds it difficult to perform a task due to effort required
Worker describes work
- As physically demanding
- Or
- Needs help with
- Can not do on own
How much can a worker lift?
- As a general rule, the heavier the load, the greater the force required to handle the load
- The level of risk is dependent on many things including how the load is handled
- Cannot accommodate to all lifting scenarios
- The number of healthy adults who can safely handle heavy loads decreases as the weight of the load increases
How can you measuring force (=/ effort)?
- Quantification of internally generated force is difficult – EMG
- Effort assessed by Borg’s scale of perceived exertion which are comparable to results of EMG.
- Push / Pull force – strain gauge
- Grip force – dynamometer
- Proxy measures: weights handled (kg)
What is repetitive movement?
- Using the same parts of the body to repeat similar movements over a period of time
- Performed > twice per minute
- Recommends tasks should be assessed if the task involves repetitive work for:
- Shoulder: if >2.5 movements/minute
- Upper arm, elbow, forearm and wrist : if > 10 movements/minute
- Fingers: estimated > 200 movements/min
- Playing a joystick on a video game can result in De Quervain’s with symptoms being reproduced after 30 minutes of playing (about 900 thumb movements
- Human tendons don’t tolerate > 1500-2000 manipulations per hour (tenosynovitis can develop even if the object handled is light)
- Keying for 400 min/day at 50wpm = 140000 strokes /day (measured with computer software)
What is a sustained posture?
Where part or all of body kept in same position for a prolonged period (>30 minutes at a time)
What is an awkward posture?
Where body parts are unbalanced, asymmetrical or at extreme ranges
- The further away a joint moves from ‘neutral’ the more awkward the posture becomes
What are 2 features of awkward/repetitive postures? What does that mean for the task?
Awkward postures that are either
- Repetitive: > twice/minute
- Sustained: held more than 30 seconds at a
- time
Increase risk of injury
Awkward + sustained posture = Hazardous ++
What are 5 reasons why sustained and awkward postures are bad?
- May stress joint components, soft tissue and reduce or occlude blood flow or nerve conduction
- Static postures can reduce blood flow through a muscle by 90% resulting in rapid onset of fatigue and predispose muscles to injury
- At the wrist (carpal tunnel), median nerve may be compressed with max pressure in full supination
- Pinching can increase extraneural pressure in the carpal tunnel in normal people
- Extreme elbow flexion places unlar nerve under stress
What are considerations of duration for manual task?
- If task is assessed to involve postures, movements or forces that are repetitive or sustained you must then consider the duration of these exposures
- Tasks performed for more than a total of 2 hours over a whole shift or continuously for more than 30 minutes at a time are considered long duration
- Evidence
- Working at VDU for >4 hours/day has a greater association with neck and shoulder pain
- Sitting and heart disease
What is vibration? What does that mean for a hazardous task?
- Vibration (whole body or hand/arm) is transferred from tools and machinery
- Using pneumatic, electric and percussive hand tools
- Operating earth moving plant
- Driving forklift, truck, tractor
- Leaning on vibrating surfaces
Static postures + whole body vibration +/- awkward posture
Increased risk of injury
What are 8 sources of risk for manual tasks?
- Design of work area and layout
- Position of benches/desks equipment
- Working at heights or confined spaces (Eg. flight attendant in aeroplane)
- Moving machinery
- The nature, size, weight or number of things handled
- Use of tools (weight, balance, handing design, maintenance)
- PPE (personal protective equipment)
- Eg. dentist wearing glove –> loss of dexterity –> grip +25% force than without glove
- System of work
- Shift patterns, resourcing, KPI’s, job rotation, level of control, monotony, cognitive demand
- The environment
- Indoor/outdoor
- Hot/cold/wet/slippery
- Ground conditions
- General public
- Psychosocial
- Emotions and moods will affect our actions and behaviours
- The Individual
- Anthropometrics
- Age
- Gender
- Health status / comorbidities
- Skill level and experience
- Experienced –> lazy with their work
- New to work –> still “motivated”
What are the risk factors and sources of risk?
B
- Time stresses
- High forces
- Sustained and repetitive postures
C
- Seated sustained and repetitive postures
- Mental stresses
D
- Seated sustained and repetitive postures
- Mental stresses
E
- Awkward postures
