Work load during floor cleaning. The effect of cleaning methods and work technique

Cardiovascular and muscle load levels were evaluated during floor cleaning. A group of 12 experienced female cleaners participated in the study. Of the subjects 6 used a mopping method and 6 a traditional scrub and cloth method. Heart rate, oxygen consumption, rating of perceived exertion, electromyography from the trapezius muscle and video recordings were obtained during floor cleaning. With respect to relative heart rate and oxygen consumption the two groups did not differ. The results revealed a high cardiovascular load corresponding on average to 53% of the individual maximal oxygen uptake. In addition 65% of the observed period was spent with the back in a position forward flexed more than 20°. The time spent in extreme forward back flexion was shorter for the mopping group. Both groups exhibited high static, median and peak shoulder muscle load levels of 10%, 25% and 54% maximal voluntary contraction, respectively. At the same time, however, the mopping group tended to have a higher shoulder load than the group using the scrub and cloth method. Furthermore, electromyographic signs of fatigue in the trapezius muscle indicated a more stereotype activation of the shoulder muscles during mopping than during scrubbing. Based on these results, it was concluded that mopping cannot be recommended as less strenuous than scrubbing.