Forward Head Posture and Its Effect on Muscle Activation
Yıl 2024,
Cilt: 9 Sayı: 1, 85 - 93, 31.03.2024
Gamze Çobanoğlu
,
Muhammed Yusuf Demirkan
,
Zeynep Berfu Ecemiş
,
Nevin Atalay Güzel
Öz
Forward head posture (FHP), which is defined as a forward displacement of the head on the cervical spine, is a common postural disorder. It is suggested that this malalignment alters the loads on the spine, affects the length-tension relationship in muscles, and changes muscle activation. Therefore, the aim of this review is to investigate the results of studies on the examination of the changes exerted by FHP on muscle activation. Although there are many methods used to assess FHP, there is no standard clinical method for accurate measurement of this angle. Photographic measurement is the most widely used, valid, and reliable assessment method. Craniovertebral angle (CVA) is the most widely used value to assess FHP in photographic measurements. A CVA of less than 48-50° is defined as FHP, although there are differences regarding the norm value of the CVA. There are many studies on the assessment of differences in the activation of the neck and shoulder muscles by making FHP and non-FHP classifications according to the CVA to show the changes in muscle activation in individuals with FHP. Although many studies have shown increased sternocleidomastoideus and upper trapezius activation, there are also others indicating no difference. Similar conflicting results exist for the lower trapezius and serratus anterior muscles. Although there are conflicting results regarding muscle activation in studies, it seems likely that muscle activation is altered in individuals with FHP. It may be recommended that physiotherapists conduct interventions by considering these differences in muscle activation in individuals with FHP.
Kaynakça
- 1. Nejati P, Lotfian S, Moezy A, Nejati M. The study of correlation between forward head posture and neck pain in Iranian office workers. Int J Occup Med Environ Health. 2015;28(2):295-303.
- 2. Ruivo RM, Pezarat-Correia P, Carita AI. Cervical and shoulder postural assessment of adolescents between 15 and 17 years old and association with upper quadrant pain. Braz J Phys Ther. 2014;18:364-71.
- 3. Lee J-h, Hwang U-j, Kwon O-y. Comparison of Muscle Thickness and Changing Ratio for Cervical Flexor Muscles During the Craniocervical Flexion Test Between Subjects With and Without Forward Head Posture. Phys Ther Korea. 2022;29(3):180-6.
- 4. Kendall FP, McCreary EK, Provance PG, Rodgers MM, Romani WA. Muscles: Testing and Function with Posture and Pain. Lippincott Williams & Wilkins, Philadelphia 2005.
- 5. Shaghayeghfard B, Ahmadi A, Maroufi N, Sarrafzadeh J. Evaluation of forward head posture in sitting and standing positions. Eur Spine J. 2016;25:3577-82.
- 6. Singla D, Veqar Z. Association between forward head, rounded shoulders, and increased thoracic kyphosis: a review of the literature. J Chiropr Med. 2017;16(3):220-9.
- 7. Khan A, Khan Z, Bhati P, Hussain ME. Influence of forward head posture on cervicocephalic kinesthesia and electromyographic activity of neck musculature in asymptomatic individuals. J Chiropr Med. 2020;19(4):230-40.
- 8. Dehqan B, Delkhoush CT, Mirmohammadkhani M, Ehsani F. Does forward head posture change subacromial space in active or passive arm elevation? J Man Manip Ther. 2021;29(4):227-34.
- 9. Kim T-h, Hwang B-h. Change of head position and muscle activities of neck during overhead arm lift test in subjects with forward head posture. Phys Ther Kore. 2019;26(2):61-8.
- 10. Mylonas K, Tsekoura M, Billis E, Aggelopoulos P, Tsepis E, Fousekis K. Reliability and Validity of Non-radiographic Methods of Forward Head Posture Measurement: A Systematic Review. Cureus. 2022;14(8):e27696.
- 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.
- 12. Weon J-H, Oh J-S, Cynn H-S, Kim Y-W, Kwon O-Y, Yi C-H. Influence of forward head posture on scapular upward rotators during isometric shoulder flexion. J J Bodyw Mov Ther. 2010;14(4):367-74.
- 13. Salahzadeh Z, Maroufi N, Ahmadi A, Behtash H, Razmjoo A, Gohari M, et al. Assessment of forward head posture in females: observational and photogrammetry methods. . J Back Musculoskelet Rehabil. 2014;27(2):131-9.
- 14. McEvoy MP, Grimmer K. Reliability of upright posture measurements in primary school children. BMC Musculoskelet Disord. 2005;6(1):1-10.
- 15. Silva AG, Punt TD, Sharples P, Vilas-Boas JP, Johnson MI. Head posture assessment for patients with neck pain: Is it useful? Int J Ther Rehabil. 2009;16(1):43-53.
- 16. Silva AG, Punt TD, Johnson MI. Reliability and validity of head posture assessment by observation and a four-category scale. Manual therapy. 2010;15(5):490-5.
- 17. Gadotti IC, Biasotto‐Gonzalez DA. Sensitivity of clinical assessments of sagittal head posture. J Eval Clin Pract. 2010;16(1):141-4.
- 18. Dimitriadis Z, Podogyros G, Polyviou D, Tasopoulos I, Passa K. The reliability of lateral photography for the assessment of the forward head posture through four different angle‐based analysis methods in healthy individuals. Musculoskelet Care. 2015;13(3):179-86.
- 19. Gallego-Izquierdo T, Arroba-Díaz E, García-Ascoz G, Val-Cano MdA, Pecos-Martin D, Cano-de-la-Cuerda R. Psychometric proprieties of a mobile application to measure the craniovertebral angle a validation and reliability study. Int J Environ Res Public Health. 2020;17(18):6521.
- 20. Van Niekerk S-M, Louw Q, Vaughan C, Grimmer-Somers K, Schreve K. Photographic measurement of upper-body sitting posture of high school students: a reliability and validity study. BMC Musculoskelet Disord. 2008;9(1):1-11.
- 21. Nam SH, Son SM, Kwon JW, Lee NK. The intra-and inter-rater reliabilities of the forward head posture assessment of normal healthy subjects. J Phys Ther Sci. 2013;25(6):737-9.
- 22. Lee H-s, Hyung-kuk C, Sun-wook P. The Analysis of severity of forward head posture with observation and photographic method. J Korean Soc Phys Med. 2015;10(3):227-35.
- 23. do Rosário JLP, Nakashima IY, Rizopoulos K, Kostopoulos D, Marques AP. Improving posture: comparing segmental stretch and muscular chains therapy. Clinical Chiropractic. 2012;15(3-4):121-8.
- 24. Grimmer-Somers K, Milanese S, Louw Q. Measurement of cervical posture in the sagittal plane. J Manipulative Physiol Ther. 2008;31(7):509-17.
- 25. Xu L, Hwang B, Kim T. The Effect of postural correction and visual feedback on muscle activity and head position change during overhead arm lift test in subjects with forward head posture. J Kor Phys Ther . 2019;31(3):151-6.
- 26. Fernández‐de‐las‐Peñas C, Alonso‐Blanco C, Cuadrado ML, Gerwin RD, Pareja JA. Trigger points in the suboccipital muscles and forward head posture in tension‐type headache. Headache. 2006;46(3):454-60.
- 27. Mani S, Sharma S, Omar B, Ahmad K, Muniandy Y, Singh DKA. Quantitative measurements of forward head posture in a clinical settings: a technical feasibility study. Eur J Physiother. 2017;19(3):119-23.
- 28. Szczygieł E, Fudacz N, Golec J, Golec E. The impact of the position of the head on the functioning of the human body: a systematic review. Int J Occup Med Environ Health. 2020;33(5):559-68.
- 29. Bokaee F, Rezasoltani A, Manshadi FD, Naimi SS, Baghban AA, Azimi H. Comparison of cervical muscle thickness between asymptomatic women with and without forward head posture. Braz J Phys Ther. 2017;21(3):206-11.
- 30. Bokaee F, Ghasemi E, Etemadi F, Naimi SS. Correlation between craniovertebral angle and thickness of longus colli in women with and without forward head posture. Middle East J Rehabil Health Stud. 2021;8(3):e112112.
- 31. Ruivo RM, Pezarat-Correia P, Carita AI. Effects of a resistance and stretching training program on forward head and protracted shoulder posture in adolescents. J Manipulative Physiol Ther. 2017;40(1):1-10.
- 32. Alowa Z, Elsayed W. The impact of forward head posture on the electromyographic activity of the spinal muscles. J Taibah Univ Med Sci. 2021;16(2):224-30.
- 33. Nishikawa Y, Watanabe K, Chihara T, Sakamoto J, Komatsuzaki T, Kawano K, et al. Influence of forward head posture on muscle activation pattern of the trapezius pars descendens muscle in young adults. Sci Rep. 2022;12(1):19484.
- 34. Lee K-J, Han H-Y, Cheon S-H, Park S-H, Yong M-S. The effect of forward head posture on muscle activity during neck protraction and retraction. J Phys Ther Sci. 2015;27(3):977-9.
- 35. Kim M-S. Neck kinematics and sternocleidomastoid muscle activation during neck rotation in subjects with forward head posture. J Phys Ther Sci. 2015;27(11):3425-8.
- 36. Khayatzadeh S, Kalmanson OA, Schuit D, Havey RM, Voronov LI, Ghanayem AJ, et al. Cervical spine muscle-tendon unit length differences between neutral and forward head postures: biomechanical study using human cadaveric specimens. Phys Ther. 2017;97(7):756-66.
- 37. Bokaee F, Dehghan Manshadi F. Performance of Longus Colli Muscle in Women with and without Forward Head Posture. Muscles Ligaments Tendons J 2021;11(1):193-200.
- 38. Valizadeh A, Rajab R, Rezazadeh F, Mahmoudpour A, Aali S. Comparison of the forward head posture on scapular muscle contributions during shoulder flexion of predominant arm in women with forward head posture. J Res Med Sci. 2014;16(6):68-72.
- 39. Kushwah K, Narvey R. EMG Analysis of Head posture at standing and sitting position. IRJET. 2018;25:1.188.
40. Mostafazadeh A, Rezazadeh F, Mahmoudpour A, Aali S. Electromyographic Activity of the Scapulothoracic Muscles during Arm Abduction with Loading in Women with Forward Head Posture and Healthy Women. Med J Tabriz Univ Med Sci. 2016;38(1):68-75.
- 41. Kiatkulanusorn S, Luangpon N, Tudpor K. Increased upper and lower trapezius muscle activities during rest in side-lying position in young adults with forward head posture. Indian J Physiother Occup. 2020;14(2):266-71.
- 42. Jafarnezhadgero A, Salahi S, Heshmati S. Electromyography activity of selected muscles during running in boys (aged range between 10-12 years) with forward head posture during running. Journal of Paramedical Sciences & Rehabilitation. 2019;8(2):7-16.
- 43. Rakholiya PA, Makwana PP, Kakkad A. To Compare the Activity of Scapular Upward Rotators during Isometric Shoulder Flexion with Forward Vs Neutral Head Posture in Normal Healthy Individuals. Indian J Occup Ther. 2019;13(2):126.
- 44. Lee S, Lee Y, Chung Y. Effect of changes in head postures during use of laptops on muscle activity of the neck and trunk. Phys Ther Rehabil Sci. 2017;6(1):33-8.
- 45. Cho J, Lee E, Lee S. Upper cervical and upper thoracic spine mobilization versus deep cervical flexors exercise in individuals with forward head posture: A randomized clinical trial investigating their effectiveness. J Back Musculoskelet Rehabil. 2019;32(4):595-602.
- 46. Kapreli E, Vourazanis E, Billis E, Oldham J, Strimpakos N. Respiratory dysfunction in chronic neck pain patients. A pilot study. Cephalalgia. 2009;29(7):701-10.
- 47. Han J, Park S, Kim Y, Choi Y, Lyu H. Effects of forward head posture on forced vital capacity and respiratory muscles activity. J Phys Ther Sci. 2016;28(1):128-31.
- 48. Kang J-I, Jeong D-K, Choi H. Correlation between pulmonary functions and respiratory muscle activity in patients with forward head posture. J Phys Ther Sci. 2018;30(1):132-5.
- 49. Song J-i, Kang S-y, Park J-h, Cynn H-s, Jeon H-s. Influence of forward head posture on electromyography activity of hyoid muscles during mouth opening. Phys Ther Korea. 2015;22(1):103-9.
- 50. Catanzariti J-F, Debuse T, Duquesnoy B. Chronic neck pain and masticatory dysfunction. Joint Bone Spine. 2005;72(6):515-9.
- 51. Gadotti I, Hicks K, Koscs E, Lynn B, Estrazulas J, Civitella F. Electromyography of the masticatory muscles during chewing in different head and neck postures-A pilot study. J Oral Biol Craniofac Res. 2020;10(2):23-7.
Baş Önde Postürü ve Kas Aktivasyonuna Etkisi
Yıl 2024,
Cilt: 9 Sayı: 1, 85 - 93, 31.03.2024
Gamze Çobanoğlu
,
Muhammed Yusuf Demirkan
,
Zeynep Berfu Ecemiş
,
Nevin Atalay Güzel
Öz
Başın servikal omurga üzerinde öne doğru yer değiştirmesi olarak tanımlanan baş önde postürü, sık görülen bir postür bozukluğudur. Bu dizilim bozukluğunun omurga üzerindeki yükleri değiştirdiği, kaslardaki uzunluk-gerilim ilişkisini etkilediği ve kas aktivasyonunu değiştirdiği ileri sürülmektedir. Bu nedenle bu derlemenin amacı, baş önde postürünün kas aktivasyonu üzerinde yaptığı değişikliklerin incelenmesine yönelik çalışmaların sonuçlarını incelemektir. Baş önde postürünü değerlendirmek için kullanılan birçok yöntem olmasına rağmen, bu açının doğru ölçümü için standart bir klinik yöntem yoktur. Fotoğrafik ölçüm en yaygın kullanılan geçerli ve güvenilir değerlendirme yöntemidir. Kraniovertebral açı (KVA), fotografik ölçümlerde baş önde postürü değerlendirmek için en yaygın kullanılan değerdir. KVA'nın norm değerinde farklılıklar olmakla birlikte, 48-50°'nin altındaki bir KVA, baş önde postürü olarak tanımlanır. Baş önde postürlü bireylerde kas aktivasyonundaki değişiklikleri göstermek için KVA'ya göre baş önde postürü olan ve olmayan olarak sınıflandırma yaparak boyun ve omuz kaslarının aktivasyonundaki farklılıkları değerlendiren birçok çalışma bulunmaktadır. Birçok çalışma sternocleidomastoideus ve üst trapezius kaslarının aktivasyonunun arttığını göstermiş olsa da, fark olmadığını gösteren çalışmalar da vardır. Alt trapezius ve serratus anterior kasları için benzer çelişkili sonuçlar mevcuttur. Çalışmalarda kas aktivasyonu ile ilgili çelişkili sonuçlar olmasına rağmen, baş önde postürü olan bireylerde kas aktivasyonunun değişmiş olması muhtemel görünmektedir. Fizyoterapistlere baş önde postürü olan bireylerde kas aktivasyonundaki bu farklılıkları göz önünde bulundurarak müdahaleler yapmaları önerilebilir.
Kaynakça
- 1. Nejati P, Lotfian S, Moezy A, Nejati M. The study of correlation between forward head posture and neck pain in Iranian office workers. Int J Occup Med Environ Health. 2015;28(2):295-303.
- 2. Ruivo RM, Pezarat-Correia P, Carita AI. Cervical and shoulder postural assessment of adolescents between 15 and 17 years old and association with upper quadrant pain. Braz J Phys Ther. 2014;18:364-71.
- 3. Lee J-h, Hwang U-j, Kwon O-y. Comparison of Muscle Thickness and Changing Ratio for Cervical Flexor Muscles During the Craniocervical Flexion Test Between Subjects With and Without Forward Head Posture. Phys Ther Korea. 2022;29(3):180-6.
- 4. Kendall FP, McCreary EK, Provance PG, Rodgers MM, Romani WA. Muscles: Testing and Function with Posture and Pain. Lippincott Williams & Wilkins, Philadelphia 2005.
- 5. Shaghayeghfard B, Ahmadi A, Maroufi N, Sarrafzadeh J. Evaluation of forward head posture in sitting and standing positions. Eur Spine J. 2016;25:3577-82.
- 6. Singla D, Veqar Z. Association between forward head, rounded shoulders, and increased thoracic kyphosis: a review of the literature. J Chiropr Med. 2017;16(3):220-9.
- 7. Khan A, Khan Z, Bhati P, Hussain ME. Influence of forward head posture on cervicocephalic kinesthesia and electromyographic activity of neck musculature in asymptomatic individuals. J Chiropr Med. 2020;19(4):230-40.
- 8. Dehqan B, Delkhoush CT, Mirmohammadkhani M, Ehsani F. Does forward head posture change subacromial space in active or passive arm elevation? J Man Manip Ther. 2021;29(4):227-34.
- 9. Kim T-h, Hwang B-h. Change of head position and muscle activities of neck during overhead arm lift test in subjects with forward head posture. Phys Ther Kore. 2019;26(2):61-8.
- 10. Mylonas K, Tsekoura M, Billis E, Aggelopoulos P, Tsepis E, Fousekis K. Reliability and Validity of Non-radiographic Methods of Forward Head Posture Measurement: A Systematic Review. Cureus. 2022;14(8):e27696.
- 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.
- 12. Weon J-H, Oh J-S, Cynn H-S, Kim Y-W, Kwon O-Y, Yi C-H. Influence of forward head posture on scapular upward rotators during isometric shoulder flexion. J J Bodyw Mov Ther. 2010;14(4):367-74.
- 13. Salahzadeh Z, Maroufi N, Ahmadi A, Behtash H, Razmjoo A, Gohari M, et al. Assessment of forward head posture in females: observational and photogrammetry methods. . J Back Musculoskelet Rehabil. 2014;27(2):131-9.
- 14. McEvoy MP, Grimmer K. Reliability of upright posture measurements in primary school children. BMC Musculoskelet Disord. 2005;6(1):1-10.
- 15. Silva AG, Punt TD, Sharples P, Vilas-Boas JP, Johnson MI. Head posture assessment for patients with neck pain: Is it useful? Int J Ther Rehabil. 2009;16(1):43-53.
- 16. Silva AG, Punt TD, Johnson MI. Reliability and validity of head posture assessment by observation and a four-category scale. Manual therapy. 2010;15(5):490-5.
- 17. Gadotti IC, Biasotto‐Gonzalez DA. Sensitivity of clinical assessments of sagittal head posture. J Eval Clin Pract. 2010;16(1):141-4.
- 18. Dimitriadis Z, Podogyros G, Polyviou D, Tasopoulos I, Passa K. The reliability of lateral photography for the assessment of the forward head posture through four different angle‐based analysis methods in healthy individuals. Musculoskelet Care. 2015;13(3):179-86.
- 19. Gallego-Izquierdo T, Arroba-Díaz E, García-Ascoz G, Val-Cano MdA, Pecos-Martin D, Cano-de-la-Cuerda R. Psychometric proprieties of a mobile application to measure the craniovertebral angle a validation and reliability study. Int J Environ Res Public Health. 2020;17(18):6521.
- 20. Van Niekerk S-M, Louw Q, Vaughan C, Grimmer-Somers K, Schreve K. Photographic measurement of upper-body sitting posture of high school students: a reliability and validity study. BMC Musculoskelet Disord. 2008;9(1):1-11.
- 21. Nam SH, Son SM, Kwon JW, Lee NK. The intra-and inter-rater reliabilities of the forward head posture assessment of normal healthy subjects. J Phys Ther Sci. 2013;25(6):737-9.
- 22. Lee H-s, Hyung-kuk C, Sun-wook P. The Analysis of severity of forward head posture with observation and photographic method. J Korean Soc Phys Med. 2015;10(3):227-35.
- 23. do Rosário JLP, Nakashima IY, Rizopoulos K, Kostopoulos D, Marques AP. Improving posture: comparing segmental stretch and muscular chains therapy. Clinical Chiropractic. 2012;15(3-4):121-8.
- 24. Grimmer-Somers K, Milanese S, Louw Q. Measurement of cervical posture in the sagittal plane. J Manipulative Physiol Ther. 2008;31(7):509-17.
- 25. Xu L, Hwang B, Kim T. The Effect of postural correction and visual feedback on muscle activity and head position change during overhead arm lift test in subjects with forward head posture. J Kor Phys Ther . 2019;31(3):151-6.
- 26. Fernández‐de‐las‐Peñas C, Alonso‐Blanco C, Cuadrado ML, Gerwin RD, Pareja JA. Trigger points in the suboccipital muscles and forward head posture in tension‐type headache. Headache. 2006;46(3):454-60.
- 27. Mani S, Sharma S, Omar B, Ahmad K, Muniandy Y, Singh DKA. Quantitative measurements of forward head posture in a clinical settings: a technical feasibility study. Eur J Physiother. 2017;19(3):119-23.
- 28. Szczygieł E, Fudacz N, Golec J, Golec E. The impact of the position of the head on the functioning of the human body: a systematic review. Int J Occup Med Environ Health. 2020;33(5):559-68.
- 29. Bokaee F, Rezasoltani A, Manshadi FD, Naimi SS, Baghban AA, Azimi H. Comparison of cervical muscle thickness between asymptomatic women with and without forward head posture. Braz J Phys Ther. 2017;21(3):206-11.
- 30. Bokaee F, Ghasemi E, Etemadi F, Naimi SS. Correlation between craniovertebral angle and thickness of longus colli in women with and without forward head posture. Middle East J Rehabil Health Stud. 2021;8(3):e112112.
- 31. Ruivo RM, Pezarat-Correia P, Carita AI. Effects of a resistance and stretching training program on forward head and protracted shoulder posture in adolescents. J Manipulative Physiol Ther. 2017;40(1):1-10.
- 32. Alowa Z, Elsayed W. The impact of forward head posture on the electromyographic activity of the spinal muscles. J Taibah Univ Med Sci. 2021;16(2):224-30.
- 33. Nishikawa Y, Watanabe K, Chihara T, Sakamoto J, Komatsuzaki T, Kawano K, et al. Influence of forward head posture on muscle activation pattern of the trapezius pars descendens muscle in young adults. Sci Rep. 2022;12(1):19484.
- 34. Lee K-J, Han H-Y, Cheon S-H, Park S-H, Yong M-S. The effect of forward head posture on muscle activity during neck protraction and retraction. J Phys Ther Sci. 2015;27(3):977-9.
- 35. Kim M-S. Neck kinematics and sternocleidomastoid muscle activation during neck rotation in subjects with forward head posture. J Phys Ther Sci. 2015;27(11):3425-8.
- 36. Khayatzadeh S, Kalmanson OA, Schuit D, Havey RM, Voronov LI, Ghanayem AJ, et al. Cervical spine muscle-tendon unit length differences between neutral and forward head postures: biomechanical study using human cadaveric specimens. Phys Ther. 2017;97(7):756-66.
- 37. Bokaee F, Dehghan Manshadi F. Performance of Longus Colli Muscle in Women with and without Forward Head Posture. Muscles Ligaments Tendons J 2021;11(1):193-200.
- 38. Valizadeh A, Rajab R, Rezazadeh F, Mahmoudpour A, Aali S. Comparison of the forward head posture on scapular muscle contributions during shoulder flexion of predominant arm in women with forward head posture. J Res Med Sci. 2014;16(6):68-72.
- 39. Kushwah K, Narvey R. EMG Analysis of Head posture at standing and sitting position. IRJET. 2018;25:1.188.
40. Mostafazadeh A, Rezazadeh F, Mahmoudpour A, Aali S. Electromyographic Activity of the Scapulothoracic Muscles during Arm Abduction with Loading in Women with Forward Head Posture and Healthy Women. Med J Tabriz Univ Med Sci. 2016;38(1):68-75.
- 41. Kiatkulanusorn S, Luangpon N, Tudpor K. Increased upper and lower trapezius muscle activities during rest in side-lying position in young adults with forward head posture. Indian J Physiother Occup. 2020;14(2):266-71.
- 42. Jafarnezhadgero A, Salahi S, Heshmati S. Electromyography activity of selected muscles during running in boys (aged range between 10-12 years) with forward head posture during running. Journal of Paramedical Sciences & Rehabilitation. 2019;8(2):7-16.
- 43. Rakholiya PA, Makwana PP, Kakkad A. To Compare the Activity of Scapular Upward Rotators during Isometric Shoulder Flexion with Forward Vs Neutral Head Posture in Normal Healthy Individuals. Indian J Occup Ther. 2019;13(2):126.
- 44. Lee S, Lee Y, Chung Y. Effect of changes in head postures during use of laptops on muscle activity of the neck and trunk. Phys Ther Rehabil Sci. 2017;6(1):33-8.
- 45. Cho J, Lee E, Lee S. Upper cervical and upper thoracic spine mobilization versus deep cervical flexors exercise in individuals with forward head posture: A randomized clinical trial investigating their effectiveness. J Back Musculoskelet Rehabil. 2019;32(4):595-602.
- 46. Kapreli E, Vourazanis E, Billis E, Oldham J, Strimpakos N. Respiratory dysfunction in chronic neck pain patients. A pilot study. Cephalalgia. 2009;29(7):701-10.
- 47. Han J, Park S, Kim Y, Choi Y, Lyu H. Effects of forward head posture on forced vital capacity and respiratory muscles activity. J Phys Ther Sci. 2016;28(1):128-31.
- 48. Kang J-I, Jeong D-K, Choi H. Correlation between pulmonary functions and respiratory muscle activity in patients with forward head posture. J Phys Ther Sci. 2018;30(1):132-5.
- 49. Song J-i, Kang S-y, Park J-h, Cynn H-s, Jeon H-s. Influence of forward head posture on electromyography activity of hyoid muscles during mouth opening. Phys Ther Korea. 2015;22(1):103-9.
- 50. Catanzariti J-F, Debuse T, Duquesnoy B. Chronic neck pain and masticatory dysfunction. Joint Bone Spine. 2005;72(6):515-9.
- 51. Gadotti I, Hicks K, Koscs E, Lynn B, Estrazulas J, Civitella F. Electromyography of the masticatory muscles during chewing in different head and neck postures-A pilot study. J Oral Biol Craniofac Res. 2020;10(2):23-7.