Effect of seat height of chair on muscle activity of erector spinae and rectus abdominis

의자 좌면 높이가 척추 세움근과 배곧은근의 근 활성도에 미치는 영향

  • Lee, Won-Hwee (Department of Physical Therapy, Jeonju Vision College)
  • 이원휘 (전주비전대학교 물리치료학과)
  • Received : 2017.05.15
  • Accepted : 2017.07.07
  • Published : 2017.07.31


This study examined the effects of the seat height of a chair on the muscle activity of the erector spinae and rectus abdominis. Thirty healthy subjects were asked to sit on chairs at three different seat heights. The muscle activities of both the erector spinae and rectus abdominis were measured by surface electromyography. The data were analyzed by repeated one way ANOVA and the muscle activity was compared according to the seat height. The alpha level was set to 0.05. The results showed that the muscle activities of the erector spinae were not significantly different among the three seat heights. The muscle activities of the rectus abdominis were significantly different among the three seat heights. Both the rectus abdominis muscle activities were significantly greater in the low seat height than the other seat heights. These results showed that the seat height of the chair affects the muscle activities of the rectus abdominis muscle, leading to musculoskeletal pain, such as low back pain. Therefore, the seat height of a chair with a correct sitting position is important for preventing musculoskeletal pain.


Chair;Electromyography;Low back pain;Seat height;Sitting position


  1. A. R. Katz, "Letter by Katz regarding article, "Television viewing time and mortality: the Australian Diabetes, Obesity and Lifestyle Study (AusDiab)", Circulation, vol. 122, no. 13, pp. e471, Sep. 2010. DOI:
  2. M. T. Hamilton, G. N. Healy, D. W. Dunstan, T. W. Zderic, N. Owen, "Too little exercise and too much sitting: Inactivity physiology and the need for new recommendations on sedentary behavior", Current Cardiovascular Risk Reports, vol. 2, no. 4, pp. 292-298, Jul. 2008. DOI:
  3. J. A. Levine, S. J. Schleusner, M. D. Jensen, "Energy expenditure of nonexercise activity", The American Journal of Clinical Nutrition, vol. 72, no. 6, pp. 1451-1455, Dec. 2000.
  4. S. A. Sahrmann, "Diagnosis and Treatment of Movement Impairment Syndrome", Mosby, USA, pp. 54-57, 2002.
  5. H. Y. Jung, J. K. Ji, S. D. Min, "Real-time Sitting Posture Monitoring System using Pressure Sensor", The Transactions of the Korean Institute of Electrical Engineers, vol. 64, no. 6, pp. 940-947, 2015. DOI:
  6. K. P. Gill, M. J. Callaghan, "The measurement of lumbar proprioception in individuals with and without low back pain", Spine, vol. 23, no. 3, pp. 371-377, Feb. 1998. DOI:
  7. L. Ghamkhar, M. Emami, M. A. Mohseni-Bandpei, H. Behtash, "Application of rehabilitative ultrasound in the assessment of low back pain: A literature review", Journal of Bodywork and Movement Therapies, vol. 15, no. 4, pp. 465-477, Oct. 2011. DOI:
  8. C. Demoulin, V. Distree, M. Tomasella, J. M. Crielaard, M. Vanderthommen, "Lumbar functional instability: a critical appraisal of the literature", Annales De Readaptation Et De Medecine Physique, vol. 50, no. 8, pp. 677-684, Nov. 2007. DOI:
  9. N. Bogduk, J. E. Macintosh, M. J. Pearcy, "A universal model of the lumbar back muscles in the upright position", Spine, vol. 17, no. 8, pp. 897-913, Aug. 1992. DOI:
  10. J. H. Lee, S. Y. Park, W. G. Yoo, "Changes in craniocervical and trunk flexion angles and gluteal pressure during VDT work with continuous cross-legged sitting", Journal of Occupational Health, vol. 53, no. 5, pp. 350-355, 2011. DOI:
  11. S. Watanabe, K. Kobara, Y. Yoshimura, H. Osaka, H. Ishida, "Influence of trunk muscle co-contraction on spinal curvature during sitting", Journal of Back and Musculoskeletal Rehabilitation, vol. 27, no. 1, pp. 55-61, 2014. DOI:
  12. Y. J. Kang, M. H. Lee, H. Y. Yeum, "Study on musculoskeletal pain by posture and types of used chairs", The Journal of Korean Society of Assistive Technology, vol. 6, no. 1, pp. 7-14, 2014.
  13. S. J. Shin, S. H. Lee, M. Y. Jung, "The Effect of Computer Work Position and Workstation on Musculoskeletal Pain", Journal of Korean Society of Occupational Therapy, vol. 12, no. 2, pp. 83-90, 2004.
  14. S. H. Yoon, S. R. Park, H. J. An, "Study on Physical Symptoms by Postures and Conditions of Used Chairs and Desks in an Elementary School Pupils", Journal of Korean Society for Hygienic Science, vol. 4, no. 1, pp. 41-54, 1998.
  15. M. S. Choi, Y. J. Chung, H. W. Jeon, "The Effect of Sitting Postures on Spinal Pelvic Curvature and Trunk Muscle Activation in Low Back Pain", Korean Research Society of Physical Therapy, vol. 16, no. 2, pp. 31-40, 2009.
  16. H. G. Jeong, Y. M. Roh, H. W. Yim, C. Y. Park, C. H. Jeong, "A relationship between cumulative trauma disorder and the type of workstation and chairs in workers with repetitive motion tasks", Korean Journal of Occupation Environment Medicine, vol. 13, no. 2, pp. 152-163, 2001.
  17. P. Hodges, A. K. Holm, S. Holm, L. Ekstrom, A. Cresswell, T. Hansson, A. Thorstensson, "Intervertebral stiffness of the spine is increased by evoked contraction of transversus abdominis and the diaphragm: In vivo porcine studies", Spine, vol. 28, no. 23, pp. 2594-2601, Dec. 2003. DOI:
  18. P. W. Hodges, A. G. Cresswell, K. Daggfeldt, A. Thorstensson, "Three dimensional preparatory trunk motion precedes asymmetrical upper limb movement", Gait & Posture, vol. 11, no. 2 pp. 92-101, Apr. 2000. DOI:
  19. S. L. Koppenhaver, J. J. Herbert, J. M. Fritz, E. C. Parent, D. S Teyhen, J. S. Magel, "Reliability of rehabilitative ultrasound imaging of the transversus abdominis and lumbar multifidus muscles", Archives of Physical Medicine and Rehabilitation, vol. 90, no. 1, pp. 87-94, Jan. 2009. DOI:
  20. P. W. Marshall, B. A. Murphy, "Core stability exercises on and off a Swiss ball", Archives of Physical Medicine and Rehabilitation, vol. 86, no. 2, pp. 242-249, Feb. 2005. DOI:
  21. J. M. McMeeken, I. D. Beith, D. J. Newham, P. Mulligan, D. J. Critchley, "The relationship between EMG and change in thickness of transversus abdominis", Clinical Biomechanics, vol. 19, no. 4, pp. 337-342, May. 2004.
  22. D. M. Urquhart, P. J. Barker, P. W. Hodges, I. H. Story, C. A. Briggs, "Regional morphology of the transversus abdominis and obliquus internus and externus abdominis muscles", Clinical Biomechanics, vol. 20, no. 3, pp. 233-241, Mar. 2004. DOI:
  23. J. E. Muscolino, "Know the body: Muscle, Bone and Palpation Essentials", Mosby, Elsevier, USA, pp. 250-255, 2012.
  24. S. M. Bierma-Zeinstra, A. M. Bohnen, R. Ramlal, J. Ridderikhoff, J. A. Verhaar, A. Prins, "Comparison between two devices for measuring hip joint motions", Clinical Rehabilitation, vol. 12, no. 6, pp. 497-505, Dec. 1998. DOI:
  25. E. Criswell, "Cram's introduction to surface electromyography second edition", Jones and Bartlett Publishers, USA, pp. 342-349, 2011.
  26. Y. G. Jung. "Effects of leg crossed sitting on the trunk muscle activities during the computer work", Dissertation of Master degree, Yonsei University, 2005.
  27. J. P. Callaghan, J. L. Gunning, S. M. McGill, "The relationship between lumbar spine load and muscle activity during extensor exercises", Physical Therapy, vol. 78, no. 1, pp. 8-18, Jan. 1998. DOI:
  28. F. P. Kendall, E. K. McCreary, P. Provance, "Muscle testing and function with posture and pain", 4th ed. Baltimore, Williams & Wilkins, pp. 147-150, 2007.
  29. S. P. Silfies, D. Squillante, P. Maurer, S. Westcott, A. R. Karduna, "Trunk muscle recruitment patterns in specific chronic low back pain populations", Clinical Biomechanics, vol. 20, no. 5, pp. 465-473, Jun. 2005. DOI:
  30. O. Shirado, T. Ito, K. Kaneda, T. E. Strax, "Flexion-relaxation phenomenon in the back muscles. A comparative study between healthy subjects and patients with chronic low back pain", American Journal of Physical Medicine & Rehabilitation, vol. 74, no. 2, pp. 139-144, Mar-Apr. 1995.
  31. P. O'Sullivan, W. Dankaerts, A. Burnett, D. Chen, R. Booth, C. Carlsen, A. Schultz, "Evaluation of the flexion relaxation phenomenon of the trunk muscles in sitting", Spine, vol. 31, no. 17, pp. 2009-2016, Aug. 2006. DOI: