Effects of mop handle height on shoulder muscle activity and perceived exertion during floor mopping using a figure eight method

Abstract

The aim of this study was to investigate effects of mop handle height on electromyographic (EMG) activities of the shoulder muscles and perceived exertion for the shoulder area during floor mopping using a figure eight method. An experimental study with 13 cleaners was conducted using surface EMG and category ratio (CR-10) scale. EMG activity was recorded unilaterally from the upper trapezius, infraspinatus, anterior and middle deltoid muscles. Each subject performed four trials of mopping and each trial consisted of using a different mop handle height (mop adjustment at the level of shoulder, chin, nose and eye) in randomized order. EMG data were normalized to a percentage of maximal voluntary contraction (%MVC). The muscle activities were assessed by estimating the 10th, 50th and 90th percentiles of the amplitude probability distribution function (APDF) of the EMG signals and analysed by linear mixed model analysis. Results showed that shoulder muscle activity was significantly lower when the mop handle height was adjusted to shoulder level or chin level as compared to eye level. These findings were supported by subjective ratings of exertion. It seems that mop handle height adjustment between shoulder and chin level may be recommended as a basis for figure eight mopping.

An Overview of Strategies for Reducing Upper Extremity Physical Exposure Associated With Floor Mopping: A Systematic Review

“…However, in examining specific categories of strategies, our analysis revealed that none of the studies met the criteria for a strong level of evidence that a specific strategy reduces physical exposure. We found moderate evidence for changes in mop design, as well as for mop adjustability (Öhrling et al, 2012; Wallius et al, 2016), as a successful strategy for reducing physical exposure. However, moderate evidence for no effect on physical exposure was found in comparisons of alternative types of tools (Table 5).…”

“…In staircase mopping, using adjustable handles decreased levels of muscle activities for the right-hand shoulder and for the left-hand wrist as well as the subjective perceptions of exertion in comparison to use of a nonadjustable mop (Öhrling et al, 2012). Similarly, Wallius et al (2016) demonstrated that by adjusting the mop handle, muscle activity levels for the shoulder and subjective exertion ratings for the shoulder area were decreased. These studies provide moderate evidence that the type of mop handle reduces physical exposure.…”

“…Those factors that have yielded positive results belong to the following major categories of strategies: (a) mop design (Conner & Irwin, 2009; Öhrling et al, 2012; Wallius et al, 2016), (b) mopping methods (Hopsu et al, 2000), (c) mopping technique (Hagner & Hagberg, 1989), and (d) work environment modifications (Kumar et al, 2005a).…”

“…Two medium-quality studies (Öhrling et al, 2012; Wallius et al, 2016) that examined adjustable-length mop handles found a reduction in physical exposure outcomes. In staircase mopping, using adjustable handles decreased levels of muscle activities for the right-hand shoulder and for the left-hand wrist as well as the subjective perceptions of exertion in comparison to use of a nonadjustable mop (Öhrling et al, 2012).…”

“…We found moderate evidence that the adjustability of mops is a technical advancement that has demonstrated reduction of physical exposure. Using adjustable handles decreased levels of muscle activities for the shoulder, and subjective perceptions of exertion both in corridor (Wallius et al, 2016) and staircase mopping (Öhrling et al, 2012). A strategy with moderate evidence can be viewed as a recommendation for “practice to consider.” Therefore, we suggest the use of adjustable mop handles as a successful strategy for reducing upper extremity exposure.…”