Experimental Measurement and Numerical Modeling of Spine Alignment of the Lateral Sleep Position and Determining the Optimal Stiffness of Mattress Elements for Male Subjects

Leilnahari, Karim; Fatouraee, Nasser; Ganjavian, Mohammad Saleh

doi:10.22041/ijbme.2011.13149

Document Type : Full Research Paper

Authors

¹ Ph.D. student and Faculty Member of Biomechanical Eng. Group, Biomedical Eng. Department, Science and Research Branch

² Associate Professor of Biomechanical Eng. Group, Department of Biomedical Eng., Amirkabir University of Technology

³ Associate Professor of the Department of the Orthopedics, Iran University of Medical Sciences

10.22041/ijbme.2011.13149

Abstract

Ergonomic factors have a direct influence on the quality of spine support during sleep. Previous studies have shown that a mattress with a homogeneous stiffness can not necessarily maintain the natural spinal alignment. Using mattresses with components of different stiffness could be considered as a possible solution instead. In this research a new mattress system having elements with different stiffness has been designed. The springs used in this mattress has been combined with a special slice of polyurethane foam, and each of them has its own specific spring constant. After acquiring the anthropometrical data of 25 male volunteers, they were asked to lie in a lateral position on soft and very stiff surfaces according to predefined conditions. Then the coordinates of the markers mounted on their spinous processes were registered through the optical tracking methods. In the next step the arrangement of the foam-spring elements were changed for each subject several times, in order to spinal alignment in a frontal plane was close to his normal alignment corresponding to the upright position. The post-processing of acquired data was considered off line.In order to qualify our experiments the BRG.LifeMod was used to model body position when lying on a mattress. The anthropometrical data of 4 subjects were used for the dimensional indexes of model. Several numerical models were built with several surfaces corresponding to the experimental essays. Once again the spinal alignment extracted. Results of both experimental and numerical modeling showed that the mattress with custom-made arrangement of the elements is an appropriate solution for the optimal support of the spine during sleep. The numerical modeling was able to predict the spinal alignment. The results of this research can be very useful in designing the custom-made sleep systems according to the ergonomic factors.

Keywords

Main Subjects

References

[1] Haex Bart_ Back and bed: ergonomic aspect of sleeping.2nd Ed. New York: CRC press; 2004.

[2] Huysmans_ T._ Haex B._ De Wilde T._ Van Audekercke R._ Vander Sloten J._ Van der Perre G._ A 3D active shape model for the evaluation of the alignment of the spine during sleeping__ Gait & Posture_ 2004_ Vol.24_ pp. 54–61.

[3] Defloor T._ the Effect of Position and Mattress on Interface Pressure_ Applied Nursing Research_ 2000_ Vol.13 (1) _ pp 2-11.

[4] Roberts K. L._ Brittin M._ Cook M.A._ Declifford J. Boomerang Pillows and Respiratory Capacity. Clinical Nursing Research_ 1994_ Vol.3_ No.2_ 157-165.

[5] Nicol K._ Rusteberg D._ Pressure Distribution on Mattresses_ Journal of Biomechanics_ 1993 Vol. 26_ No. 12_ pp. 1479-1486.

[6] Vanderwee K._ Grypdonck M._ Defloor T._ Alternating pressure air mattresses as prevention for pressure ulcers: A literature review_ International Journal of Nursing Studies_ 2008_ Vol. 45_ pp 784–801.

[7] Tamura_ T._ Miyasako S._ Ogawa M._ Togawa T._ Fujimoto T._ Assessment of bed temperature monitoring for detecting body movement during sleep: comparison with simultaneous video image recording and actigraphy _ Medical Engineering & Physics_ 1999_ Vol.21_ pp.1-8

[8] Lee_ H._ Park_ S._ Quantitative effects of mattress types (comfortable vs. uncomfortable) on sleep quality through polysomnography and skin temperature_ International Journal of Industrial Ergonomics. 2006. Vol.36_ pp 943–949.

[9] Bader_ G_ Engdal S._ The influence of bed firmness on sleep quality_ Applied Ergonomics_ 2000_ Vol.31 pp. 487-497.

[10] Lahm R._ Iaizzo P.A_ Physiologic responses during rest on a sleep system at varied degrees of firmness in a normal population_ Ergonomics_ 2002_ Vol.11 pp.798- 818.

[11] Derman K.L._ Derman E.W._ Noakes T.D._ A lumbar body support (KBS2000) alters lumbar muscle recruitment patterns in patients with acute-upon-chronic lower back pain_ Journal South African Medical_ 1995_ Vol.84(4)_pp.278-282.

[12] Leilnahari K., Alamdari R., Fatouraee N., measurement of spinal muscle's electrical signal in male athletes as lateral lying mode for determination of activity amount on the two bed system , Jahesh ,2010, First year , No. 4, Winter , 2010 , pp 31-38

[13] Jacobson B.H._ Gemmell H._ Hayes B.M._ Altena Th._ Effectiveness Of A Selected Bedding System On Quality Of Sleep_ Low Back Pain_ Shoulder Pain_ And Spine Stiffness Journal of Manipulative And Physiological Therapeutics_ 2002_ Vol.25(2)_ pp.88-92

[14] Jacobson B.H._ Wallace T.J._ Gemmell H._ subjective rating of perceived back pain_ stiffness and sleep quality following introduction of medium-firm bedding systems_Journal Of Chiropractic Medicine_2006_ Vol. 5(4)_ pp. 128-134.

[15] Jacobson B.H._ Wallace T.J._ Smith D.B._ Kolb T._ Grouped comparisons of sleep quality for new and personal Bedding systems_ Applied Ergonomics_ 2008_ Vol. 39(2)_ pp.247-54.

[16] Kovacs F._ Abraira V._ Peña A._ Martín-Rodríguez J._ Sánchez-Vera M._ Ferrer E._ Ruano D._ Guillén P._ Gestoso M._ Muriel A._ Effect of firmness of mattress on chronic non-specific low-back pain: randomized_ double-blind_ controlled_ multicentre trial_The Lancet_ 2003_ Vol.362(9396 )_ pp.1599-1604.

[17] DeVochta J.W._ Wilderb D. G._ Bandstrab E.R._ Sprattc K.F._ Biomechanical evaluation of four different mattresses_ Applied Ergonomics_ 2006_Vol.37 _ pp. 297–304.

[18] Linder Ganz E._ Gefen A. Mechanical compressioninduced pressure sores in rat hind limb: muscle stiffness_ histology_ and computational models’_ J. Appl. Physiol._ 2004 Vol. 96_ pp. 2034-2049.

[19] Standard Documents, ISO 2439:2001_ Flexible cellular polymeric materials. Determination of hardness(indentation technique)

[20] Cooperstein R._ Haneline M.T._ Spinous process palpation using the scapular tips as landmark vs a radiographic criterion standard_ Journal of Chiropractic Medicine_ 2007_ Vol. 6_ pp.87-93.

[21] Gordon S.J._ Grimmer K.A._ Trott P._ Sleep position_ age_ gender_ sleep quality and walking Cervicothoracic symptoms. The internet journal of allied health sciences and practice _ 2007 _ Vol. 5(1).pp1-8

[22] White A.A._ Panjabi M.M._ Clinical Biomechanics of the Spine__ 1990_ ISBN 0-397-50720-8 Second Edition_

[23] Adams M.A_ Dolan P._ Spine biomechanics_ Journal of Biomechanics_ 2005_ Vol.38_ pp.1972–1983

Iranian Journal of Biomedical Engineering

Experimental Measurement and Numerical Modeling of Spine Alignment of the Lateral Sleep Position and Determining the Optimal Stiffness of Mattress Elements for Male Subjects

References

References

Volume 5, Issue 2 - Serial Number 2
June 2011
Pages 161-170

Experimental Measurement and Numerical Modeling of Spine Alignment of the Lateral Sleep Position and Determining the Optimal Stiffness of Mattress Elements for Male Subjects

References

References

Volume 5, Issue 2 - Serial Number 2June 2011Pages 161-170

Volume 5, Issue 2 - Serial Number 2
June 2011
Pages 161-170