A predictive discomfort measure considering the combined neck and trunk is introduced in this work and compared with the seat-to-head transmissibility and subjective reported discomfort due to fore-aft whole-body vibration of seated subjects under two sitting postures. Five subjects were tested using discrete sinusoidal frequencies in the range of 0.5–12 Hz. All files were run at a constant acceleration of 0.8 m/s2. The subjects were tested with back support and without back support, and their subjective discomfort measure was reported based on the Borg CR-10 scale. The results have demonstrated that the predictive discomfort was invulnerable to the measurement locations and has shown consistency with the subjective discomfort for both sitting conditions. The seat-to-head transmissibility showed less consistency with the subjective discomfort and was sensitive to the locations of the output point on the head and to the components of the motion included in the transmissibility calculation at these locations.
BorgG., 1982. A category scale with ratio properties for intermodal and interindividual comparisons. In: GeisslerH.G. and PetzoldP., Editors, Psychophysical Judgment and the Process of Perception, Deutscher Verlag der Wissenschaften, Berlin, pp. 25–33.
2.
CourtneyA.J.CahnA.H.S., 1999. Ergonomics of grab unloaders for bulk materials handling. International Journal of Industrial Ergonomics23, 61–66.
3.
DemicM.LukicJ., 2009. Investigation of the transmission of fore and aft vibration through the human body. Applied Ergonomics40, 622–629.
4.
DickeyJ.P.OliverM.L.BoileauP.-E.EagerT.R.TrickL.M.EdwardsA.M., 2006. Multi-axis sinusoidal whole-body vibrations: Part 1 – How long should the vibration and rest exposures be for reliable discomfort measures?Journal of Low Frequency Noise, Vibration and Active Control25, 175–184.
5.
EgerT.StevensonJ.CallaghanJ.P.GrenierS.VibRG, 2008. Predictions of health risks associated with the operation of load-haul-dump mining vehicles: Part 2-Evaluation of operator driving postures and associated postural loading. International Journal of Industrial Ergonomics38, 801–815.
6.
GenaidyA.M.KarwowskiW., 1993. The effects of neutral posture deviation on perceived joint discomfort ratings in sitting and standing postures. Ergonomics36, 785–792.
7.
GriffinM. J.LewisC.H.ParsonsK.C.WhithamE.M., 1979. The biodynamic response of the human body and its application to standards. AGARD Conference Proceedings (CP-253). In: Models and analogues for the evaluation of human biodynamic response, performance, and protection, Paris, France, (von GierkeH.E., ed). Paper A28. Avisory Group on Aerospace Reseaech and Development.
8.
GriffinM.J., 1990. Handbook of Human Vibration, Academic Press, London, UK.
9.
HwangC.L.YoonK., 1981. Multiple Attribute Decision Making: Method and Application. Spring, New York.
10.
JackR. J.EgerT., 2008. The effects of posture on seat-to-head whole-body vibration transmission. Journal of Low Frequency Noise, Vibration and Active Control27, 309–325.
11.
JohanningE.LandsbergisP.FischerS.ChristE.GöresB.LuhrmanR., 2006. Whole-body vibration and ergonomic study of US railroad locomotives. Journal of Sound and Vibration298, 594–600.
12.
KeeD.KarwowskiW., 2001. LUBA: As assessment technique for postural loading on the upper body based on joint motion discomfort and maximum holding time. Applied Ergonomics32, 357–366.
13.
KeeD.KarwowskiW., 2003. Ranking systems for evaluation of joint and joint motion stressfulness based on perceived discomforts. Applied Ergonomics34, 167–176.
14.
MaedaS.MansfieldN.J.ShibataN., 2008. Evaluation of subjective response to whole-body vibration exposure: Effect of frequency content. International Journal of Industrial Ergonomics38, 509–515.
15.
MarlerT.RahmatallaS.ShanhanM.Abdel-MalekK., 2005. A new discomfort function for optimization-based posture prediction. SAE Digital Human Modeling for Design and Engineering Conference. SAE. International. Iowa City, Iowa, USA.
16.
PaddanG.S.GriffinM.J., 1992. The transmission of translational seat vibration to the head: The effect of measurement position at the head. Proceedings of the Institute of Mechanical Engineers, Part H: Journal of Engineering in Medicine206, 159–168.
17.
PaddanG.S.GriffinM.J., 1998. A review of the transmission of translational seat vibration to the head. Journal of Sound and Vibration215, 863–882.
18.
RahmatallaS.DeShawJ., 2011. Predictive Discomfort of Non-Neutral Head-Neck Postures in Fore-Aft Whole-Body Vibration. Ergonomics (accepted for publication)
19.
RahmatallaS.SmithR.MeuschJ.XiaT.MarlerT.ContrattoM., 2010. A quasi-static discomfort measure in whole-body vibration. Industrial Health48, 645–653.
20.
RahmatallaS.XiaT.ContrattoM.KoppG.WilderD.Frey-LawL.AnkrumJ., 2008. Three-dimensional Motion Capture Protocol for Seated Operators in Whole Body Vibration. International Journal of Industrial Ergonomics38, 425–433.
21.
RehnB.NilssonT.OlofssonB.LundstormR., 2005. Whole-Body Vibration exposure and non-neutral neck postures during occupational use of all-terrain vehicles. The Annals of Occupational Hygiene49, 267–275.
22.
RehnB.NilssonbT.LundstroR.HagbergdM.BurstroL., 2009. Neck pain combined with arm pain among professional drivers of forest machines and the association with whole-body vibration exposure. Ergonomics52, 1240–1247.
23.
SubashiG.NawaysehN.MatsumotoY.GriffinM.J., 2009. Nonlinear subjective and dynamic responses of seated subjects exposed to horizontal whole-body vibration. Journal of Sound and Vibration321, 416–434.
24.
WangW.RakhejaS.BoileauP.E., 2008. Relationship between measured apparent mass and seat-to-head transmissibility responses of seated occupants exposed to vertical vibration. Journal of Sound and Vibration314, 907–922.
25.
WhithamE.M.GriffinM.J., 1978. The effects of vibration frequency and direction on the location of areas of discomfort caused by whole-body vibration. Applied Ergonomics9, 231–239.
26.
WilderD.G.WoodworthB.B.FrymoyerJ.W.PopeM.H., 1982. Vibration and the Human Spine. Spine7, 243–254.
