Most jobs in the workforce involve carrying out manual tasks in some shape, way or form. They include a wide range of activities that involve using the body to move or hold an object, people or animals. Examples of manual tasks include stacking shelves, working on a conveyor line or sitting at a computer. Although, some manual tasks are hazardous and can cause serious injury like musculoskeletal disorders (MSDs).
Hazardous manual tasks do not have to involve any external force. Your own body weight in an abnormal or sustained posture may be risky.
A hazardous manual task is where a person engages in a process that puts their body at risk of suffering an injury. These tasks include lifting, lowering, pushing, pulling, carrying or otherwise moving, holding or restraining any person, animal or thing involving one or more of the following:
- repetitive or sustained force
- high or sudden force
- repetitive movement
- sustained or awkward posture
- exposure to vibration.
An MSD means an injury to, or a disease of, the musculoskeletal system, whether occurring suddenly or over time. It can be a back injury, a sprained or strained muscle, ligament and tendon, degeneration of a joint or bone, and nerve damage such as carpal tunnel syndrome. These ailments can all result from poorly managed hazardous manual tasks.
Refer to page 3 of the Code for more information.
- individual factors
- psychosocial factors
- work organisation
- work layout and awkward postures
- load and forceful movements
- task invariability
- environmental issues.
These factors combine in a way that magnifies their effect. By only addressing one or two factors and not all of them, you are unlikely to achieve the goal in preventing injury.
Source: HabitAtWork - DPI
There are a range of persons under the Work Health and Safety Act 2012 (SA) (the Act) that have specific duties. Those duty holders and their duties are:
- A person conducting a business or undertaking has the primary duty to ensure, so far as is reasonably practicable, that workers and other persons are not exposed to health and safety risks arising from the business or undertaking.
- Designers, manufacturers, importers and suppliers of plant and structures have a duty to ensure, so far as is reasonably practicable, that the plant or structure they design, manufacture, import or supply is without risks to health and safety (see Chapter 6 of the Hazardous manual tasks - Code of Practice for further guidance).
- Officers, such as company directors, have a duty to exercise due diligence to ensure that the business or undertaking complies with the WHS Act and Regulations. This includes taking reasonable steps to ensure that the business or undertaking has and uses appropriate resources and processes to eliminate or minimise risks that arise from hazardous manual tasks.
- Workers have a duty to take reasonable care for their own health and safety and ensure they do not adversely affect the health and safety of other persons.
To manage the risks associated with hazardous manual tasks, a duty holder must:
- identify hazards which could g ive rise to the risk
- eliminate the risk so far as is reasonably practicable
- minimise the risk by implementing control measures in accordance with the hierarchy of control, if it is not reasonably practicable to eliminate the risk
- maintain the control measure so that it remains effective
- review risk control measures in accordance with the Work Health and Safety Regulations 2012 (SA).
For an overview of the risk management process for manual tasks, refer to Appendix A of the Hazardous manual tasks - Code of Practice.
Static loading refers to physical exertion in which the same posture or position is held throughout the exertion. These types of exertions put increased loads or forces on the muscles and tendons, which contributes to fatigue. This occurs because not moving impedes the flow of blood that is needed to bring nutrients to the muscles and to carry away the waste products of muscle metabolism. Examples of static postures include gripping tools that cannot be put down, holding the arms out or up to perform tasks, or standing in one place for prolonged periods.
Some principles of “motion-economy” that reduce the range of physical movement are now recognised as hazardous due to their effect on increasing static work at the expense of healthy dynamic movement.
Sedentary work poses a real threat to worker safety and is linked to a range of health problems including:
- musculoskeletal disorders
- cardiovascular disease
- poor mental health
- some cancers
- premature death.
The negative health effects from prolonged sitting are due to:
- insufficient movement and muscle activity
- low energy expenditure
- not moving enough
- not changing posture enough
General task rotation, combined with a mixture of sitting, standing and movement throughout your day is the best way to reduce the impact of sedentary work.
There are several ways you can be on the lookout for hazardous manual tasks, including:
- consulting your workers who are affected, or likely to be affected by a manual task, as they will provide valuable information about discomfort, muscular aches and pains which can signal potential hazards
- reviewing available information such as records of workplace injuries and accidents, inspection reports and workers compensation claims as they can help identify which manual tasks may cause harm
- observing trends as they may show certain tasks have more characteristics which make them hazardous. This will help the decision process in determining which manual tasks should be addressed as a priority.
Assess the risks
Conducting a risk assessment is the best way to help examine the traits of the relative hazardous manual task in more detail. It is required for any manual tasks that have been identified as being dangerous unless the risk is well known and you know how to control it.
A risk assessment is great for helping determine:
- which postures, movements (or lack of movement) and forces of the task pose a risk
- where they pose a risk during the task
- why they are occurring
- what needs to be fixed.
Determine the risk factors
The following questions are provided to help assist in determining which postures, movements and forces of the task pose a risk.
For assistance, refer to the Hazardous manual tasks - Code of Practice for guidance when answering.
- repetitive movement?
- sustained or awkward postures?
- repetitive or sustained forces?
- mental stress / tension?
As a general guideline, the term ‘repetitive’ means that a movement or force is performed more than twice a minute, while ‘sustained’ means a posture or force is held for more than 30 seconds at a time.
If a ‘yes’ response is given to Question 1, then the time taken to complete the task should be determined.
As a general guideline, if the task is done for more than a total of two hours over a whole shift, or continuously for more than 30 minutes at a time, there is a risk of MSD.
Force is the amount of muscular effort required to perform, attempt to perform, resist or change a movement. Forceful muscular exertions can overload muscles, tendons, joints and discs and are associated with most musculoskeletal disorders.
High force is exerted when large loads, relative to the body part doing the activity, are placed on muscles and other tissues. An indicator of a high force is when a worker describes a task as physically demanding, needs help to do it, requires a stronger person or two people to do the task, or where a normally one-handed task requires two hands.
Sudden force occurs when there is a rapid increase or decrease in muscular effort. Examples of sudden force include jarring, jerky or unexpected movements. It is particularly hazardous because the body must suddenly adapt to the changing force. Tasks which include sudden force typically generate high force as well. Accelerating too fast when applying force, or trying to catch a falling load, can create sudden hazardous forces.
Prolonged exposure to the whole body or hand-arm vibration increases the risk of MSDs and other health problems. The degree of risk increases as the duration of exposure increases and when the amplitude of vibration is high. Examples of tasks involving vibrations include the use of hand-powered tools or operating a mobile plant.
The task involves a risk of MSD if you have answered ‘yes’ to either:
- Question 1 and Question 2
- Question 3
If you answered ‘yes’ to Question 4, the task may be a risk but requires further investigation.
A task may involve more than one risk factor. The more risk factors that are present, the higher the risk of MSD.
If you identify a risk, you need to think about the sources of these risks that are present in the task as you may be able to change these to eliminate or reduce the risk of MSD.
The main sources of risk are:
- work area design and layout
- the nature, size, weight or number of things handled in performing the manual task
- systems of work
- the environment in which the manual task is performed.
Controlliong the risk
As shown below, duty holders are required by the Work Health and Safety Regulations 2012 (SA) to work through the hierarchy of control to choose the control that most effectively eliminates or minimises the risk. This can either involve a single control measure or a combination of two or more different controls.
Eliminating the risk is the most effective control measure and involves eradicating the hazardous manual task along with its associated risk. However, if it isn’t reasonably practicable to eliminate the risk, then you must minimise the risks as much as possible.
|Hierarchy of control||Examples of control measures|
For the most effective controls, it is recommended to:
- start at the top of the hierarchy of control
- enable workers to test controls and give their feedback before decisions are made to make them permanent
- develop work procedures to ensure that controls are understood and responsibilities are clear
- communicate the reasons for the change to workers and others
- ensure that any equipment used in the manual task is properly maintained
- provide training to ensure workers can proficiently implement the risk controls that includes
- information about manual tasks risk management, specific manual tasks risk
- and how to control them, use of mechanical aids, tools, equipment and safe work procedures and how to report a problem or maintenance issue.
Training in lifting techniques has been shown to be relatively ineffective compared to ‘higher level’ controls. Therefore training should never be used as the sole means to controlling the risk of hazardous manual tasks, unless higher levels of the hierarchy of control can be proven to be impracticable for the situation(s) concerned.
Review control measures
Control measures that have been implemented should be reviewed and, if necessary, revised to make sure they work as planned whilst maintaining a work environment that is without risk to health and safety.
You should review control measures:
- when the control measure is no longer effective
- before a change is made that is likely to give rise to a new or different risk
- if a new hazard is identified
- if consultation indicates a review is necessary
- if a health and safety representative requests a review.
- Work Health and Safety Regulations 2012 (SA) (Chapter 4 Part 2 Hazardous Manual Tasks)
- Hazardous manual tasks - Code of Practice
- Hazardous manual tasks - Risk assessment worksheet