The building cleaning sector constitutes one of the largest groups by the BG BAU, and musculoskeletal diseases and complaints are widespread among the cleaning personnel. One means of reducing the physical workloads arising during cleaning work is by the use of cleaning equipment of enhanced ergonomic design. Against this background, the BG BAU commissioned a study of a number of mop handles. The study was to compare these handles with regard to their effect/impact upon body postures and movements. The results were to support the BG BAU in formulating recommendations for cleaning equipment, and possibly to reveal information relevant to further development of such equipment. The information obtained can be used during the assessment of tasks that impose a load upon the joints, and also as a basis for the formulation of recommendations for suitable prevention measures.
In the initial phase of the project, the existing international literature on the subject of musculoskeletal workloads arising during floor cleaning work was examined and evaluated. Laboratory studies were then planned. Three floor mops supplied by the BG BAU ("standard" (straight) adjustable-length mop handle; straight mop handle with rotating end grip; S-curved mop handle with rotating lower grips and rotating end grip) were selected for the performance of a standardized floor cleaning task (damp wiping of a floor surface of 5 m × 5 m in the IFA's laboratory).
In order for the physiological parameters to be determined qualitatively and quantitatively, relevant body postures/movements and joint angles (wrist, elbow, shoulder joints, back) were recorded by means of the VICON measurement system (non-contact motion capture system). Parallel to these measurements, questionnaires employing rating scales were used to record the test subjects' subjective impressions. Examples of the different forces exerted in the arm and shoulder region under loading caused by floor mopping tasks were estimated in a pilot phase by means of surface electromyography (sEMG, measurement of the muscle activity in the shoulder and lower arm region). Seventeen volunteers (employees of a cleaning company) took part in the laboratory study, which took the form of a cross-sectional comparison study. The task entailed cleaning of a defined floor area with use of each of the three mop handles (sequence random; the task was performed three times with each mop handle). The procedure was based upon the usual recommendations (walking backwards and wiping in figures of eight). Only test subjects free of complaints were allowed to take part in the study.
Analysis of the results of the tests involving the seventeen volunteer floor cleaners revealed differences, in some cases significant, between the three different types of floor mop handle design, with respect both to different physiological parameters and to the individual subjective assessments of the handles.
The high muscular workload, already described in the literature, arising during prolonged performance of this task was confirmed by the sEMG measurements. It was shown that differences between floor mop handles in their geometry or facility for adjustment and use may permit a reduction in joint angle loadings, particularly those of the wrists. This may however require a suitable or longer period of practice or accustomization than is the case for conventional handle types, since incorrect use of the handles may also have undesirable effects. The predominantly negative subjective assessments of the handle type that differed particularly strongly from the conventional shape should therefore be considered in the context of a brief practice and test duration.
To conclude, the cleaning equipment should be selected in consideration of the anticipated duration of the workload. The results of the study suggest that a conventional mop handle is suitable for occasional and brief cleaning of small areas and that the associated slightly greater physical workload can be tolerated. By contrast, where larger floor areas are repeatedly cleaned manually and the cleaning tasks are longer in duration, higher initial investment (in time and financial outlay) in a mop handle with special ergonomic features should be considered, in order for the resulting physical workload to be reduced.
construction industryType of hazard:
musculoskeletal disorders (except cancer), working equipment, ergonomicsDescription, key words:
floor cleaning mops, musculoskeletal loads, mop handle, ergonomics