When you screed a concrete slab by hand, you need to bend over and use a strong grip to pull the board over the wet material.
This often involves twisting, crouching and being exposed to awkward postures. It also requires considerable shoulder and arm force.
Where done over long periods, this can lead to fatigue and pain and can place stress on the back, knees, hands, arms and shoulders.
This may lead to serious muscle or joint injuries.
This is especially problematic on larger jobs, which can take hours to complete.
As outlined below, screeding is only one of one of many common tasks in construction which can lead to musculoskeletal disorders (MSD).
The problem is serious.
Across all sectors of the economy, almost 18,000 workers (17,780) suffered a musculoskeletal or connective tissue disorder related injury in 2018/19 for which serious claims for workers compensation were lodged, the latest data from Safe Work Australia indicates (no breakdown for construction specifically was given).
This forced the average worker to spend almost ten weeks off the job and cost an average of $15,800 per claim in compensation alone.
On aggregate, lost work time due to MSD injury in 2018/19 alone totalled 174,244 weeks or more than 3,350 years.
This is not counting the pain suffered by workers or the disruption to their lives.
All this raises questions about how MSDs occur and what can be done to prevent them.
Such issues were addressed by Alice Cheng, State Inspector – Ergonomics at SafeWork NSW, during a recent SafetyCast which was streamed by the regulator.
The happened as the regular launched its MSD in Construction project last month.
This will run for three months and will include site visits from inspectors to ensure compliance and to provide advice.
According to Cheng, MSD is an umbrella term which describes a range of injuries to various parts of the body which can include muscles, nerves, tendons, joints, cartilage or the spine.
It can include sprains and strains of muscles or ligaments, back injuries and nerve injuries such as carpel tunnel syndrome.
The most common way for this to occur is through gradual wear and tear in joints ligaments or muscles. This is caused by repeated or ongoing use of those body parts.
Less commonly, it can be caused by sudden damage due to strenuous activity or unexpected movement, This can occur through catching a falling object or suddenly needing to change posture when handling something heavy.
MSDs can also result from a combination of both causes.
When it comes to job sites or construction, MSDs can commonly result from manual tasks such as lifting, lowering, pushing, pulling, carrying, moving, holding or restraining a person, animal or object such as a piece of equipment.
These tasks become hazardous where one or more of four ‘risk factors’ is involved (see below).
The first risk factor is force. This describes the amount of muscular effort which is required for a task.
It can be categorised into:
- Repetitive force, which could include gripping or handling bricks whilst bricklaying
- Sustained force, which could include supporting a plasterboard sheet when fixing it to a ceiling.
- High force, which can be caused by lifting, carrying or lowering a heavy object.
- Sudden force is caused by repetitive movement.
Next, there is repetitive movement.
This involves workers using the same body parts over and over again. It can commonly occur during painting or bricklaying.
The third risk factor is posture.
This can be significant where workers need to maintain a sustained posture, such as when supporting plasterboard sheets while they are being nailed into place.
It can also be problematic where awkward postures are involved, such as where electricians need to work with their arms above their head or where plumbers need to work below knee level.
Finally, there is vibration.
Here, workers can be exposed to whole body vibration when operating machinery or hand-arm vibration where using hand-held tools such as jackhammers.
In terms of prevention, Cheng said it is critical to follow a risk management process for manual tasks.
The first step is to identify which tasks are potentially hazardous – which will be indicated by the presence or absence of one or more of the aforementioned risk factors.
When going about this, it is important to engage with workers to identify problem areas. As the people on the front line, Cheng says workers are often best place to advise about specific concerns with particular tasks.
One idea is to use a ‘discomfort survey’. This asks workers about the types of jobs from which they typically go home with soreness, are most afraid of getting hurt from or which involve manual handling which makes them feel like they do not want to come to work.
Business can also look at trends from information which they collect to identify where hazardous manual tasks are occurring.
This includes information such as injury data, inspection reports and issues raised by workers.
Finally, it is important to observe how tasks are being performed and to see in practice how it is being done.
Next, it is important to consider what lies behind the level of risk involved. Could there be, for instance, a lack of available mechanical aids? Is inadequate maintenance of equipment leading to workers being exposed to vibration?
Once you understand both the nature of the risk involved and the source of the problem, Cheng says you can target solutions to address this.
When designing solutions, Cheng says it is important to consider the hierarchy of control measures.
Under this hierarchy, risks should be controlled by first eliminating the risk completely where possible and then through other measures such as redesigning tasks to minimise or avoid hazards.
In the screeding example above, one solution could be to use motorised screeds and to therefore avoid the requirement for workers to bend over.
Only after each of these options have been exhausted should administrative measures (such as training on correct operating procedures) or personal protective equipment be relied upon.
This is one are where Cheng says approaches often fall down.
When thinking about safety when lifting, for example, she says many businesses think immediately of two-person lifts or lifting technique training as the main control measure.
In fact, these measures operate and the lowest level of control and provide the lowest level of protection out of all measures within the hierarchy.
Instead, employers could look first at mechanical lifting aids or redesigning tasks to either minimise the degree of lifting involved or to avoid lifting altogether.
Finally, Cheng stresses the importance of worker involvement.
In one organisation with which she works, Cheng says workers are involved in decisions regarding identifying hazards, designing solutions and even purchasing equipment and supplies.
“It is important to talk to and consult with workers others such as suppliers, engineers and maintenance officers who you think should be involved as they often have the best insights to problem areas,” Cheng says.
“Your workers are the ones doing the task. They will know the task very well. They are the best people to involve and to go to in the risk management process to help identify problems and appropriate solutions.”