Hacka rätt och må bra

This report deals with an investigation of the working environment when using manual weeding implements and small motor weeders in plantations and vegetable gardening. Factors taken into account include ergonomics, weeding effect and the length of time required to treat a given area. In the case of motor driven equipment, levels of noise and handle vibration were also examined and certain measurements of force were carried out. The report includes a technical description of the equipment covered in the study. In a survey of literature on ergonomics, the injuries which can be caused by incorrect working posture and strain are described. In our own experiments, the subjects graded the strain on different parts of the body when working with the various pieces of equipment. As it is seldom possible to adjust the equipment to suit individual height and build, different sorts of problems were experienced by the research subjects. For example, a tall person may have to stoop, with resulting pains in the back and shoulders. A person of small build, on the other hand, may find the weight of the equipment cumbersome. The noise levels of motor weeders were measured. Hearing protection must be used when levels exceed 85 dB (A). Of the motor weeders examined, all but one, the Honda F405, had excessive noise levels. There are set standards for the amount of vibration which is acceptable in various work situations and which involves no risk of long term injury to the body. Injuries which can occur include so-called white fingers and tingling and numbness in the fingers. Our own research has shown that the vibration levels for several machines were far too high to be acceptable. High vibration levels can occur especially when working in ground which is hard or stony. Working in hard or stony ground can also lead to high levels of static and dynamic strain on the body. As each piece of equipment is used for a relatively short period of time, it is difficult to draw any definite conclusions on its efficiency as regards time consumption. A fact which may cause surprise is that there was very little difference in time consumption between using manual weeding implements and motor weeders. Using motor driven equipment was, on the whole, a little faster, but the difference was marginal. There were no great differences in the weeding results after treatment with the various pieces of equipment. Generally it can be said that not too much time should elapse between treatments. The bigger the weeds have grown, the greater the force required to cut them down or hack them up. The large plants also cause problems by getting entangled in the hacking devices of the motor weeder, which must then be cleared from plant debris before being able to function properly again. In the discussion, it is maintained that those who use manual and motor driven equipment for weed control in their jobs have a working environment which is unacceptable and which subjects them to several risks. In order to come to terms with this problem, measures are required to improve and develop new equipment. It is also necessary to improve the design of the area which is to be worked on. Training in the use of this type of equipment can also contribute to a reduction, in the future, in the number of people with work related injuries.