title: Full-shift and task-specific upper extremity muscle activity among US large-herd dairy parlour workers.
abstract: US large-herd dairy parlour workers experience a high prevalence of musculoskeletal symptoms in the upper extremity. The purpose of this study was to estimate and compare full-shift and task-specific muscle activity of the upper extremity among parlour workers. Surface electromyography data were recorded continuously throughout a full work shift for each participant (n = 60). For a subset of participants (n = 33), muscular effort was estimated for milking task cycles. Lower muscle activity levels and higher per cent muscular rest was observed among rotary parlour participants as compared to herringbone and parallel parlour participants for anterior deltoid, forearm flexor and forearm extensor muscles. These findings suggest rotary parlours may offer workstation designs or work organisational dynamics which may be more beneficial to the health and performance of the worker, as compared to parallel or herringbone parlours. Practitioner Summary: Study findings suggest milking parlour configurations present different biomechanical demands on workers which may influence worker health and performance. Our findings will enable more informed decisions regarding both engineering (e.g. parlour configuration or milking equipment) and administrative (e.g. work organisation) control strategies for large-herd milking parlours.
authors.affiliation: a School of Public Health in San Antonio , University of Texas Health Science Center at Houston , San Antonio , TX , USA.
authors.forename: David I
authors.initials: DI
authors.lastname: Douphrate
authors.affiliation: b College of Public Health , University of Iowa , Iowa City , IA , USA.
authors.forename: Nathan B
authors.initials: NB
authors.lastname: Fethke
authors.affiliation: b College of Public Health , University of Iowa , Iowa City , IA , USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Nonnenmann
authors.affiliation: a School of Public Health in San Antonio , University of Texas Health Science Center at Houston , San Antonio , TX , USA.
authors.forename: Anabel
authors.initials: A
authors.lastname: Rodriguez
authors.affiliation: c Dairy Extension , New Mexico State University , Clovis , NM , USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Hagevoort
authors.affiliation: a School of Public Health in San Antonio , University of Texas Health Science Center at Houston , San Antonio , TX , USA.
authors.forename: David
authors.initials: D
authors.lastname: Gimeno Ruiz de Porras
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D003612:Dairying / Q000379:methods; D004576:Electromyography; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D013647:Task Performance and Analysis; D014481:United States; D034941:Upper Extremity / Q000502:physiology*; D055815:Young Adult
keywords: Agriculture ergonomics; biomechanics; equipment design; intervention effectiveness; task analysis