Several things affect the extent to which the back is placed under load when lifting and carrying.
Whether lifting is considered to be heavy and hence harmful to health is dependent in the first instance on an assessment of the weight of the load and how far away it is.
The red, yellow and green assessment model in the drawing (lifting diagram) shows weight limits for two different lifting distances. Lifting close to the body is rarely possible in practice unless carrying slings are used, for example, and so this is not included in the assessment diagram.
If lifting takes place in the green area in the assessment diagram, lifting will initially not be regarded as harmful to health.
Conversely, lifting in the red area in the assessment diagram, lifting will always be regarded as harmful to health and may present an acute risk of back injury. Therefore, arrangements must be put in place promptly to counter the risk.
Lifting in the yellow area may also be harmful to health if other factors besides weight and distance make lifting more difficult.
Therefore, lifting in the yellow area must always be examined in greater detail.
In the first instance, it is necessary to examine whether the following aggravating factors are present:
- Bending the back forwards.
- Twisting or asymmetric strain on the back.
- Raised arms.
Unless at least one of the above aggravating factors is present on lifting, lifting will not normally be regarded as harmful to health.
If at least one of the above aggravating factors is present, the frequency and duration of lifting must also be included in the assessment.
This assessment is carried out in accordance with the table below:
Your muscles remain tense the whole time when you lift or carry an object for a long period, and so your muscles become tired relatively quickly. If you walk at the same time, your back will be twisted and under an uneven strain.
The size and shape of the load must not block your view or impair your posture when you carry something so that you risk bumping into something. If you trip, slip or bump into something while you are carrying something, your body is subject to major strain.
Repeated minor injuries increase the risk of longer-term problems.
Avoid carrying anything other than small tools up ladders and stairs as this increases the risk of acute injury and accidents involving falls.
If it is not possible to use suitable technical aids to transport loads horizontally or vertically, you must take the following into account when carrying objects:
- The weight of the load must not exceed approx. 20 kg, and the transport route must not be more than approx. 20 m long. At the same time, the load must be held symmetrically and close to the body.
- A step is equivalent to 1 metre. If the centre of gravity of the load is at lower arm distance or 3/4 arm distance, the maximum weight of the load is reduced to 12 and 6 kg respectively.
Prevention of injury resulting from lifting and carrying
Planning, work site layout and the use of technical aids and correct working techniques can help to prevent overloading.
- Technical aids must be used for transporting and installation of heavy and unwieldy loads such as doors, windows, radiators, washbasins, beams, rafters, roof plates, plasterboard, forms, kerbstones, concrete elements, element supports, etc.
- Some handling can be reduced by supplying correctly packaged materials at the right time and to the right place.
- A truck-mounted crane should be used when loading and unloading heavy plant and materials.
- Delivery and storage must take place as close as possible to the point of use and in such a manner that objects can be transported/installed unimpeded using the selected technical aids.
- Plasterboard, concrete elements and other structural components must always be supplied together with a user guide in Danish which includes a description of the weight of the component together with information on how it should be handled and fitted/installed properly from the point of view of safety.
- Cranes, trucks, telescopic loaders, plaster trolleys, sack trucks, etc. are used as often as possible instead of carrying. Plasterboard, etc. can be supplied to the work site, packed in the order in which it is to be used and cut to size, which may save a certain amount of handling.
- There is equipment for lifting objects onto floors, trolleys and workbenches, with vacuum lifting fitted for installation, etc.
- Lifting below knee height and above shoulder height can be avoided by initially having the objects placed on a trestle or workbench/trolley at a suitable height.
Lifting and carrying techniques
Do not lift objects if you are in any doubt as to whether you can manage the load. Using the correct lifting and carrying techniques reduces the risk of injury.
- Walk up close to the load. Stand facing the load in a walking position.
- Assess the weight of the load and the position of its centre of gravity.
- Make sure you get a good grip on the load.
- Bend your knees and hips and keep your back balanced by tensing your abdominal and back muscles.
- Lift the load calmly by straightening your knees and hips.
- Hold the load close to your body, with your elbows slightly bent.
- Lift and carry the load symmetrically, i.e. centrally to your body or carrying equal weight in both hands.
- Avoid twisting your back when you are holding a load. Hold your back straight and turn your feet.
- When setting down the load, use the same movements but in the opposite order.
The following rules also apply:
- The surface must be even and firm, and your footwear must be flexible and not loose.
- The transport route must be tidy, well lit and as flat as possible. It must not be smooth.
- The load or parts of it must not be able to fall down and strike the carrier or others.