The Effect of Different Head Positions in Sitting on Head/Shoulder Posture and Muscle Activity

앉은 자세에서 머리 위치가 머리/어깨의 자세와 근활성도에 미치는 영향

  • Kwon, Jung-Won (Department of Rehabilitation Science, Graduate School, Daegu University) ;
  • Nam, Seok-Hyun (Department of Rehabilitation Science, Graduate School, Daegu University) ;
  • Choi, Yong-Won (Department of Rehabilitation Science, Graduate School, Daegu University) ;
  • Kim, Chung-Sun (Department of Physical Therapy, College of Rehabilitation Science, Daegu University)
  • 권중원 (대구대학교 대학원 재활과학과) ;
  • 남석현 (대구대학교 대학원 재활과학과) ;
  • 최용원 (대구대학교 대학원 재활과학과) ;
  • 김중선 (대구대학교 대학원 재활과학과)
  • Received : 2013.07.24
  • Accepted : 2013.08.19
  • Published : 2013.08.25

Abstract

Purpose: This study was to investigate whether the two different head postures, natural and ideal head posture, affect head/shoulder posture and muscle activity. Methods: Thirty healthy subjects with the forward head and round shoulder posture were participated in this study. This study utilized a within-subjects design with subjects being positioned into two sitting positions: natural head posture (NHP) and ideal head posture (IHP). Forward head angle (FHA) and forward shoulder angle (FSA) of each subject were measured for assessing the head/shoulder posture and muscle activities of upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) during the forward overhead reaching. Results: There were significant increases in both FHA and FSA after taking IHP, which showed greater angles than in taking NHP. In change of muscle activities, there were significant decreases in both LT and SA after taking IHP, which showed lower activities than in taking a NHP, whereas there was no significant change in UT. Conclusion: These findings demonstrate that postural alterations associated with forward head and rounded shoulder postures could alter scapular kinetics and muscle activity during the forward overhead reaching.

Keywords

References

  1. Quek J, Pua YH, Clark RA et al. Effects of thoracic kyphosis and forward head posture on cervical range of motion in older adults. Man Ther. 2013;18(1):65-71. https://doi.org/10.1016/j.math.2012.07.005
  2. Park SK, Park JM, Lee JH. Push-up plus exercise program on scapular position and muscle activity in individuals with rounded shoulder posture. J Korean Soc Phys Ther. 2010;22(5):1-8. https://doi.org/10.1589/jpts.22.1
  3. Borstad JD, Ludewig PM. The effect of long versus short pectoralis minor resting length on scapular kinematics in healthy individuals. J Orthop Sports Phys Ther. 2005;35(4):227-38. https://doi.org/10.2519/jospt.2005.35.4.227
  4. Finley MA, Lee RY. Effect of sitting posture on 3-dimensional scapular kinematics measured by skin-mounted electromagnetic tracking sensors. Arch Phys Med Rehabil. 2003;84(4):563-8. https://doi.org/10.1053/apmr.2003.50087
  5. Ludewig PM, Cook TM, Nawoczenski DA. Three-dimensional scapular orientation and muscle activity at selected positions of humeral elevation. J Orthop Sports Phys Ther. 1996;24(2):57-65. https://doi.org/10.2519/jospt.1996.24.2.57
  6. Weon JH, Jung DY. Comparison of the muscle activities of upper trapezius and middle deltoid between subjects with and without elevation of shoulder girdle during arm elevation. J Korean Soc Phys Ther 2012;24(6):388-92.
  7. Lee MH, Song JM, Kim JS. The effect of neck exercises on neck and shoulder posture and pain in high school students. J Korean Soc Phys Ther 2011;23(1):29-35. https://doi.org/10.1589/jpts.23.29
  8. Chae YW. The effect of forward head posture and cervical rom on chronic and episodic tension-type headache in university students. J Korean Soc Phys Ther. 2009;21(2):71-7. https://doi.org/10.1589/jpts.21.71
  9. Bae YH, Lee GC. Effect of motor control training with strengthening exercises on pain and muscle strength of patients with shoulder impingement syndrome. J Korean Soc Phys Ther. 2011;23(6):1-7. https://doi.org/10.1589/jpts.23.1
  10. McClure PW, Michener LA, Karduna AR. Shoulder function and 3-dimensional scapular kinematics in people with and without shoulder impingement syndrome. Phys Ther. 2006;86(8):1075-90.
  11. Lewis JS, Green A, Wright C. Subacromial impingement syndrome: The role of posture and muscle imbalance. J Shoulder Elbow Surg. 2005;14(4):385-92. https://doi.org/10.1016/j.jse.2004.08.007
  12. Ludewig PM, Cook TM. Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Phys Ther. 2000;80(3):276-91.
  13. Silva AG, Johnson MI. Does forward head posture affect postural control in human healthy volunteers? Gait Posture. 2012.
  14. Kang JH, Park RY, Lee SJ et al. The effect of the forward head posture on postural balance in long time computer based worker. Ann Rehabil Med. 2012;36(1):98-104. https://doi.org/10.5535/arm.2012.36.1.98
  15. Raine S, Twomey LT. Head and shoulder posture variations in 160 asymptomatic women and men. Arch Phys Med Rehabil. 1997;78(11):1215-23. https://doi.org/10.1016/S0003-9993(97)90335-X
  16. Caneiro JP, O'Sullivan P, Burnett A et al. The influence of different sitting postures on head/neck posture and muscle activity. Man Ther. 2010;15(1):54-60. https://doi.org/10.1016/j.math.2009.06.002
  17. Falla D, O'Leary S, Fagan A et al. Recruitment of the deep cervical flexor muscles during a postural-correction exercise performed in sitting. Man Ther. 2007;12(2):139-43. https://doi.org/10.1016/j.math.2006.06.003
  18. Szeto GP, Straker LM, O'Sullivan PB. Emg median frequency changes in the neck-shoulder stabilizers of symptomatic office workers when challenged by diffe rent physical stressors. J Electromyogr Kinesiol. 2005;15(6):544-55. https://doi.org/10.1016/j.jelekin.2005.06.004
  19. Yoo WG, Kim MH. Effect of different seat support characteristics on the neck and trunk muscles and forward head posture of visual display terminal workers. Work. 2010;36(1):3-8.
  20. Yoo WG, Yi CH, Kim MH. Effects of a ball-backrest chair on the muscles associated with upper crossed syndrome when working at a vdt. Work. 2007;29(3):239-44.
  21. Weon JH, Oh JS, Cynn HS et al. Influence of forward head posture on scapular upward rotators during isometric shoulder flexion. J Bodyw Mov Ther. 2010;14(4):367-74. https://doi.org/10.1016/j.jbmt.2009.06.006
  22. Thigpen CA, Padua DA, Michener LA et al. Head and shoulder posture affect scapular mechanics and muscle activity in overhead tasks. J Electromyogr Kinesiol. 2010;20(4):701-9. https://doi.org/10.1016/j.jelekin.2009.12.003
  23. Villanueva MB, Jonai H, Sotoyama M et al. Sitting posture and neck and shoulder muscle activities at different screen height settings of the visual display terminal. Ind Health. 1997;35(3):330-6. https://doi.org/10.2486/indhealth.35.330
  24. Harrison AL, Barry-Greb T, Wojtowicz G. Clinical measurement of head and shoulder posture variables. J Orthop Sports Phys Ther. 1996;23(6):353-61. https://doi.org/10.2519/jospt.1996.23.6.353
  25. Grimmer-Somers K, Milanese S, Louw Q. Measurement of cervical posture in the sagittal plane. J Manipulative Physiol Ther. 2008;31(7):509-17. https://doi.org/10.1016/j.jmpt.2008.08.005
  26. Silva AG, Punt TD, Johnson MI. Reliability and validity of head posture assessment by observation and a four-category scale. Man Ther. 2010;15(5):490-5. https://doi.org/10.1016/j.math.2010.05.002
  27. Silva AG, Punt TD, Sharples P et al. Head posture assessment for patients with neck pain: Is it useful? Int J Ther Rehabil. 2009;16(1):43-53. https://doi.org/10.12968/ijtr.2009.16.1.37939
  28. Netto KJ, Burnett AF. Reliability of normalisation methods for emg analysis of neck muscles. Work. 2006;26(2):123-30.
  29. Hermens HJ, Freriks B, Disselhorst-Klug C et al. Development of recommendations for semg sensors and sensor placement procedures. J Electromyogr Kinesiol. 2000;10(5):361-74. https://doi.org/10.1016/S1050-6411(00)00027-4
  30. Solomonow M, Baratta RV, Banks A et al. Flexion-relaxation response to static lumbar flexion in males and females. Clin Biomech (Bristol, Avon). 2003;18(4):273-9. https://doi.org/10.1016/S0268-0033(03)00024-X
  31. Kebaetse M, McClure P, Pratt NA. Thoracic position effect on shoulder range of motion, strength, and three-dimensional scapular kinematics. Arch Phys Med Rehabil. 1999;80(8):945-50. https://doi.org/10.1016/S0003-9993(99)90088-6
  32. Ludewig PM, Phadke V, Braman JP et al. Motion of the shoulder complex during multiplanar humeral elevation. J Bone Joint Surg Am. 2009;91(2):378-89. https://doi.org/10.2106/JBJS.G.01483
  33. Thigpen CA, Gross MT, Karas SG et al. The repeatability of scapular rotations across three planes of humeral elevation. Res Sports Med. 2005;13(3):181-98. https://doi.org/10.1080/15438620500222489