DOI QR코드

DOI QR Code

A Comparison of Shoulder Muscle Activities on Sitting Posture and Shoulder Angle

  • Park, Gyeong-ju (Dept. of Physical Therapy, College of Medical Science, Jeonju University) ;
  • Park, Sun-young (Dept. of Physical Therapy, College of Medical Science, Jeonju University) ;
  • Lee, Eun-jae (Dept. of Physical Therapy, College of Medical Science, Jeonju University) ;
  • Jeong, Su-hyeon (Dept. of Physical Therapy, College of Medical Science, Jeonju University) ;
  • Kim, Su-jin (Dept. of Physical Therapy, College of Medical Science, Jeonju University)
  • Received : 2018.01.03
  • Accepted : 2018.02.05
  • Published : 2018.02.19

Abstract

Background: Sitting posture influences movements of scapulothoracic and glenohumeral joints and changes the shoulder muscle activities. The development and maintenance of correct sitting posture is important for the fundamental treatment of shoulder pain during rehabilitation. Objects: The purpose of this study was to investigate the effects of the sitting postures and the shoulder movements on shoulder muscle activities for both male and female. Methods: Twenty-eight subjects without shoulder-related diseases participated in this experiment. The subjects had randomly adopted three different sitting postures (upright posture, preferred posture, maximum slouched posture) and shoulder flexion angles in scapular plane ($30^{\circ}$, $90^{\circ}$, $120^{\circ}$). Surface electrodes were collected from upper trapezius (UT), anterior deltoid (AD), and posterior deltoid (PD) and the active shoulder range of motion was measured in each sitting posture and shoulder flexion angle. Results: The active range of motions of the shoulder external rotation and the flexion in the scapular plane decreased from the upright posture to the maximum slouched posture (p<.05, mixed-effect linear regression with random intercept, Tukey post-hoc analysis). All muscles showed the highest EMG activities at $120^{\circ}$ shoulder flexion with the maximum slouched posture and did not show the gender differences. Conclusion: Increased shoulder muscle activities may become the potential risk factor for the shoulder impairment and pain if people continuously maintain the maximum slouched posture. Therefore, an upright position is necessary during shoulder exercises, as well as in activities of daily living, including motions involving lifting the arms.

Keywords

References

  1. Alizadehkhaiyat O, Hawkes DH, Kemp GJ, et al. Electromyographic analysis of shoulder girdle muscles during common internal rotation exercises. Int J Sports Phys Ther. 2015;10(5):645-654.
  2. Brookham RL, Wong JM, Dickerson CR. Upper limb posture and submaximal hand tasks influence shoulder muscle activity. Int J Ind Ergon. 2010;40(3):337-344. https://doi.org/10.1016/j.ergon.2009.11.006
  3. Bullock MP, Foster NE, Wright CC. Shoulder impingement: The effect of sitting posture on shoulder pain and range of motion. Man Ther. 2005;10(1):28-37. https://doi.org/10.1016/j.math.2004.07.002
  4. 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
  5. Culham E, Peat M. Functional Anatomy of the Shoulder Complex. J Orthop Sport Phys Ther. 1993;18(1):342-350. https://doi.org/10.2519/jospt.1993.18.1.342
  6. Ebaugh DD, McClure PW, Karduna AR. Three-dimensional scapulothoracic motion during active and passive arm elevation. Clin Biomech(Bristol. Avon). 2005;20(7):700-709. https://doi.org/10.1016/j.clinbiomech.2005.03.008
  7. Ekstrom RA, Donatelli RA, Soderberq GL. Surface electromyographic analysis of exercises for the trapezius and serratus anterior muscles. J Orthop Sports Phys Ther. 2003;33(5):247-258. https://doi.org/10.2519/jospt.2003.33.5.247
  8. 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):563-568. https://doi.org/10.1053/apmr.2003.50087
  9. Kanlayanaphotporn R. Changes in sitting posture affect shoulder range of motion. J Bodyw Mov Ther. 2014;18(2):239-243. https://doi.org/10.1016/j.jbmt.2013.09.008
  10. 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):945-950. https://doi.org/10.1016/S0003-9993(99)90088-6
  11. Lee ST, Moon J, Lee SH, et al. Changes in activation of serratus anterior, trapezius and latissimus dorsi with slouched posture. Ann Rehabil Med. 2016;40(2):318-325. https://doi.org/10.5535/arm.2016.40.2.318
  12. Liu J, Hughes RE, Smutz WP, et al. Roles of deltoid and rotator cuff muscles in shoulder elevation. Clin Biomech (Bristol. Avon). 1997;12(1):32-38. https://doi.org/10.1016/S0268-0033(96)00047-2.
  13. Ludewig PM, Cook TM. Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Phys Ther. 2000;80(3):276-291. https://doi.org/10.2519/jospt.1993.17.5.212.
  14. 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
  15. Ludewig PM, Reynolds JF. The Association of Scapular Kinematics and Glenohumeral Joint Pathologies. J Orthop Sport Phys Ther. 2009;39(2):90-104. https://doi.org/10.2519/jospt.2009.2808
  16. Malmstromm EM, Olsson J, Baldetorp J, et al. A slouched body posture decreases arm mobility and changes muscle recruitment in the neck and shoulder region. Eur J Appl Physiol. 2015;115(12):2491-2503. https://doi.org/10.1007/s00421-015-3257-y
  17. McLean L. The effect of postural correction on muscle activation amplitudes recorded from the cervicobrachial region. J Electromyogr Kinesiol. 2005;15(6):527-535. https://doi.org/10.1016/j.jelekin.2005.06.003
  18. Nagai K, Tateuchi H, Takashima S, et al. Effects of trunk rotation on scapular kinematics and muscle activity during humeral elevation. J Electromyogr Kinesiol. 2013;23(3):679-687. https://doi.org/10.1016/j.jelekin.2013;01.012
  19. Nairn BC, Chisholm SR, Drake JD. What is slumped sitting? A kinematic and electromyographical evaluation. Man Ther. 2013;18(6):498-505. https://doi.org/10.1016/j.math.2013.03.003
  20. Neumann DA. Kinesiology of the Musculoskeletal System: Foundations for rehabilitation. 3rd ed. St. Louis, Missouri, Elsevier Inc., 2017:149-151.
  21. Nie HL, Arendt-Nielsen L, Kawczynski A, et al. Gender effects on trapezius surface EMG during delayed onset muscle soreness due to eccentric shoulder exercise. J Electromyogr Kinesiol. 2007;17(4):401-409. https://doi.org/10.1016/j.jelekin.2006.04.006
  22. O'Sullivan PB, Dankaerts W, Burnett AF, et al. Effect of different upright sitting postures on spinal-pelvic curvature and trunk muscle activation in a pain-free population. Spine (Phila Pa 1976). 2006;31(19):(E)707-712. https://doi.org/10.1097/01.brs.0000234735.98075.50
  23. Pascarelli EF, Hsu YP. Understanding Work-Related Upper Extremity Disorders: Clinical Findings in 485 Computer Users, Musicians, and Others. J Occup Rehabil. 2001;11(1):1-21. https://doi.org/10.1023/A:1016647923501
  24. Schuldt K, Ekholm J, Harms-Ringdahl K, et al. Effects of changes in sitting work posture on static neck and shoulder muscle activity. Ergonomics. 1986;29(12):1525-1537. https://doi.org/10.1080/00140138608967266
  25. Sciascia A, Kuschinsky N, Nitz AJ, et al. Electromyographical comparison of four common shoulder exercises in unstable and stable shoulders. Rehabil Res Pract. 2012;2012:783824. https://doi.org/10.1155/2012/783824
  26. Uga D, Endo Y, Nakazwa R, et al. Electromyographic analysis of the infraspinatus and scapular stabilizing muscles during isometric shoulder external rotation at various shoulder elevation angles. J Phys Ther Sci. 2016;28(1):154-158. https://doi.org/10.1589/jpts.28.154