Print Email Facebook Twitter Comparison of four specific dynamic office chairs with a conventional office chair: Impact upon muscle activation, physical activity and posture Title Comparison of four specific dynamic office chairs with a conventional office chair: Impact upon muscle activation, physical activity and posture Author Ellegast, R.P. Kraft, K. Groenesteijn, L. Krause, F. Berger, H. Vink, P. Publication year 2012 Abstract Prolonged and static sitting postures provoke physical inactivity at VDU workplaces and are therefore discussed as risk factors for the musculoskeletal system. Manufacturers have designed specific dynamic office chairs featuring structural elements which promote dynamic sitting and therefore physical activity. The aim of the present study was to evaluate the effects of four specific dynamic chairs on erector spinae and trapezius EMG, postures/joint angles and physical activity intensity (PAI) compared to those of a conventional standard office chair. All chairs were fitted with sensors for measurement of the chair parameters (backrest inclination, forward and sideward seat pan inclination), and tested in the laboratory by 10 subjects performing 7 standardized office tasks and by another 12 subjects in the field during their normal office work. Muscle activation revealed no significant differences between the specific dynamic chairs and the reference chair. Analysis of postures/joint angles and PAI revealed only a few differences between the chairs, whereas the tasks performed strongly affected the measured muscle activation, postures and kinematics. The characteristic dynamic elements of each specific chair yielded significant differences in the measured chair parameters, but these characteristics did not appear to affect the sitting dynamics of the subjects performing their office tasks. © 2011 Elsevier Ltd and The Ergonomics Society. Subject OrganisationSP - Sustainable ProductivityBSS - Behavioural and Societal SciencesWork and EmploymentWorkplaceHealthy LivingDynamic office chairsEMGPhysical activityPostureVDU/computer workplaceDynamic elementsEMGErector spinaeMuscle activationOffice chairPhysical activityPostureRisk factorsSitting postureStructural elementsActivation analysisMuscleDynamicsadultarticlebiomechanicsbody posturechaircontrolled studyelectromyogramequipment designerector spinae muscleergonomicsfemalehumanhuman experimentjob performancejoint anglemalemuscle contractionmusculoskeletal system parametersnormal humanoffice chairphysical activitysittingskeletal muscletrapezius muscle To reference this document use: http://resolver.tudelft.nl/uuid:19786ee8-67b8-40fc-a5fb-3f92d2429760 DOI https://doi.org/10.1016/j.apergo.2011.06.005 TNO identifier 442915 ISSN 0003-6870 Source Applied Ergonomics, 43 (2), 296-307 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.