Physical stress in the workplace
Around 670,000 employees in Switzerland suffer from physical impairments and miss an average of three days of work a year: a high cost. Christian Müller, Head of Ergonomics at Suva, explains in an interview with SAFETY-PLUS what the most common mistakes are when carrying physical loads.
Mr. Müller, what is your job at Suva?
As an occupational safety specialist and ergonomics expert, I am in close contact with companies and advise them on a wide range of problems related to the prevention of occupational accidents and diseases. Our ergonomists are always consulted when serious physical stresses are involved that can lead to serious occupational illnesses. In each case, we check whether health and safety is being implemented at the workplace.
Has the field of ergonomics gained in importance at Suva in recent years?
The ergonomics department has existed at Suva for 25 years. In recent years, however, we have registered an increase in insurance costs in the area of ergonomics, whereupon the topic has recently become somewhat more the focus of our prevention work.
What physical problems do most of the outages in plants have to do with?
One third of the days lost are related to musculoskeletal complaints. Occupational groups such as home delivery services, the finishing trade or nursing staff are frequently affected. But we also have other industries with risk factors such as highly repetitive activities, for example in vegetable growing.
What hazards occur in beverage logistics, which Suva also focuses on?
When delivering beverages, whether for home delivery or delivery to restaurants, the load is particularly heavy. During the day, the hand trucks are used to transport hundreds of 25-kilo barrels. Just imagine the city of Bern, for example, with its many narrow spiral staircases. The finishing trade, too, for example when working on windows and floors, records very high physical loads due to load transport. The typical physical stresses caused by forced postures and repetitive activities, on the other hand, are more likely to be observed in the industrial sector.
Why isn't construction at the top of the list?
A prevention project called "Optibau" already exists for load transport on the construction site. This principle was developed in 2015 and will be increasingly focused on again this year. We currently see very high risks of severe physical strain, especially in industries where general cargo is transported to a wide variety of locations. Following this prevention campaign, we also want to address other industries, for example companies involved in parcel delivery services.
Across industries, what are the most common physical load carrying mistakes?
One of the main mistakes is not questioning whether one should carry a load at all. This is where effective measures must always be taken. When it comes to transporting loads, people who are professionally involved in lifting and carrying loads usually have a good technique and also appropriate relief aids. On the other hand, we often find that untrained people often bend their knees too low because they confuse a "straight back" with an "upright back." However, having a straight back does not mean that you can no longer lean forward. If lifting is done with an erect back, it leads to very low squat positions and increased stress on the knees. Furthermore, many people are often unaware that a load such as a harasse, for example, can be pulled closer to them over a corner in order to be able to distribute the weight load - at close range - over the entire body.
There are various guide and limit values for the maximum loads. These are often misinterpreted. Why?
The 7 and 12 kg are guideline values for frequently moving loads for women and men, respectively. The 15 kg for women and 25 kg for men are guide values for occasional handling of loads. "Frequently" means four times per hour. If the guideline values are exceeded, a company must carry out hazard assessments, e.g. using our checklists. If hazards are present, the company must take appropriate measures. In addition to the actual load, the frequency of load handling, the execution conditions and the break design play a decisive role.
The prevention module "Handling loads cleverly" also addresses leg work. To what extent can legwork relieve the strain of lifting and transporting?
A straight back does not necessarily mean an upright upper body. We have the strongest muscles in our buttocks and thighs. If we carry loads close to us with a straight back and lift them with the strength from our legs, we make optimal use of these forces. Due to the anatomical characteristics of the human body, the leg muscles, as well as the supporting muscles of the upper body, can work optimally with a straight back. With a round back, some of these muscle groups are "turned off".
Repetitive lifting of smaller objects is also a common problem, from which incorrect postures arise. How can you counteract this problem?
Repetitiveness is a risk factor for physical discomfort regardless of the load. With rather light objects, it makes sense to make optimal use of the mobility of the back. If one wants to optimize the work technique, this should be done in the company with the concrete examples and means from the everyday work. There are various ways of doing this, for example by making notes or paying attention to how other employees perform the same activities. If bad routines have already crept in, a change in behavior requires a lot of time and effort. The same mistake is often made with new tools. For example, a new tool such as a scissor lift table may be introduced and employees are told that they will now work with this tool. One should not underestimate how much time it takes to train employees even with new tools. The failure of introducing a "stair climber" is a classic example. There were companies that purchased some of these aids, which then just stood around in the corner. But when we went around the companies and trained the employees, the employees were extremely satisfied and didn't want to give the aid away.
If employees are already affected by certain MSDs: How does a company deal with these employees?
Complaints can have different causes. In addition to occupational stress, there are also many risk factors from private life. If several employees have the same complaints, it becomes clear where a company has a problem and appropriate measures need to be defined. Risks for physical stress belong in the hazard portfolio. In this way, preventive measures can be taken and complaints avoided. Someone who already has complaints may not be able to continue working with their reduced resilience.