title: 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.
authors.affiliation: Institution of Public Health and Clinical Nutrition, Ergonomics, School of Medicine, University of Eastern Finland, Finland.
authors.forename: Mari-Anne
authors.initials: MA
authors.lastname: Wallius
authors.forename: Saara M
authors.initials: SM
authors.lastname: Rissanen
authors.forename: Timo
authors.initials: T
authors.lastname: Bragge
authors.forename: Paavo
authors.initials: P
authors.lastname: Vartiainen
authors.forename: Pasi A
authors.initials: PA
authors.lastname: Karjalainen
authors.forename: Kimmo
authors.initials: K
authors.lastname: Räsänen
authors.forename: Susanna
authors.initials: S
authors.lastname: Järvelin-Pasanen
mesh_terms: D000328:Adult; D057645:Deltoid Muscle / Q000502:physiology; D004576:Electromyography; D004867:Equipment Design; D005260:Female; D005430:Floors and Floorcoverings; D006796:Household Work / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D005082:Physical Exertion; D017006:Rotator Cuff / Q000502:physiology; D064171:Superficial Back Muscles / Q000502:physiology; D055815:Young Adult