Phys. Ther. Korea 2020; 27(4): 272-277
Published online November 20, 2020
https://doi.org/10.12674/ptk.2020.27.4.272
© Korean Research Society of Physical Therapy
Ji-yeon Eun1 , PT, BPT, Oh-yun Kwon2
, PT, PhD, Ui-jae Hwang1,2
, PT, PhD, Sung-hoon Jung1,2
, PT, PhD, Sun-hee Ahn1,2
, PT, PhD
1Department of Physical Therapy, Graduate School, Yonsei University, 2Department of Physical Therapy, College of Health Science, Laboratory of Kinetic Ergocise Based on Movement Analysis, Yonsei University, Wonju, Korea
Correspondence to: Oh-yun Kwon
E-mail: kwonoy@yonsei.ac.kr
https://orcid.org/0000-0002-9699-768X
Background: Forward head posture (FHP) is common postural malalignment. FHP is described relatively extension to upper cervical and lower cervical is relatively flexion. Although several researchers mentioned the lower cervical flexion posture in FHP, most of the studies related to FHP is focused on the deep cervical flexor function.
Objects: The purposes of present study is to compare the cervical strength (upper cervical extension [UCE], lower cervical extension [LCE], upper cervical flexion [UCF], lower cervical flexion [LCF]) between individuals with and without FHP.
Methods: Fifty-one participants are recruited. Participants who have the craniovertebral angle (CVA) less than 48 degree were classified to the FHP group (n = 24) and the others were included in without FHP group (n = 27). The cervical strength (UCE, LCE, UCF, LCF) were measured using Smart KEMA strength sensor and the strength data was normalized by body weight. All strength measurement conducted at head and neck neutral position in sitting. Independent t-test was used to compare the cervical strength between individuals with and without FHP.
Results: The mean value of CVA was greater in without FHP group than with FHP group (p < 0.000). The strength value of UCF (p < 0.002) and LCE (p < 0.001) was significant less in FHP group than without FHP group. But no significant differences were seen in the LCF and UCE strength between two groups.
Conclusion: UCF and LCE weakness in FHP group should be considered to evaluate and manage the individuals with FHP.
Keywords: Head, Neck, Posture
Phys. Ther. Korea 2020; 27(4): 272-277
Published online November 20, 2020 https://doi.org/10.12674/ptk.2020.27.4.272
Copyright © Korean Research Society of Physical Therapy.
Ji-yeon Eun1 , PT, BPT, Oh-yun Kwon2
, PT, PhD, Ui-jae Hwang1,2
, PT, PhD, Sung-hoon Jung1,2
, PT, PhD, Sun-hee Ahn1,2
, PT, PhD
1Department of Physical Therapy, Graduate School, Yonsei University, 2Department of Physical Therapy, College of Health Science, Laboratory of Kinetic Ergocise Based on Movement Analysis, Yonsei University, Wonju, Korea
Correspondence to:Oh-yun Kwon
E-mail: kwonoy@yonsei.ac.kr
https://orcid.org/0000-0002-9699-768X
Background: Forward head posture (FHP) is common postural malalignment. FHP is described relatively extension to upper cervical and lower cervical is relatively flexion. Although several researchers mentioned the lower cervical flexion posture in FHP, most of the studies related to FHP is focused on the deep cervical flexor function.
Objects: The purposes of present study is to compare the cervical strength (upper cervical extension [UCE], lower cervical extension [LCE], upper cervical flexion [UCF], lower cervical flexion [LCF]) between individuals with and without FHP.
Methods: Fifty-one participants are recruited. Participants who have the craniovertebral angle (CVA) less than 48 degree were classified to the FHP group (n = 24) and the others were included in without FHP group (n = 27). The cervical strength (UCE, LCE, UCF, LCF) were measured using Smart KEMA strength sensor and the strength data was normalized by body weight. All strength measurement conducted at head and neck neutral position in sitting. Independent t-test was used to compare the cervical strength between individuals with and without FHP.
Results: The mean value of CVA was greater in without FHP group than with FHP group (p < 0.000). The strength value of UCF (p < 0.002) and LCE (p < 0.001) was significant less in FHP group than without FHP group. But no significant differences were seen in the LCF and UCE strength between two groups.
Conclusion: UCF and LCE weakness in FHP group should be considered to evaluate and manage the individuals with FHP.
Keywords: Head, Neck, Posture
Table 1 . Measurement of strength in the UCE, LCE, UCF, and LCF.
Measurement | Figure | Instruction |
---|---|---|
Upper cervical extensor | ![]() | The strap is placed on the subject’s chin, and the opposite end of the strap is fixed at the immobile bar located behind the subjects’ head. The strength sensor is placed between the subject and the immobile bar. The subject is indicated to rotate his/her chin superiorly against the resistance of the strap. |
Lower cervical extensor | ![]() | The strap is placed behind the subject’s occipital bone and the opposite end of the strap is fixed on the immobile bar in front of the subject. The subject is indicated to move his/her head in a posterior translatory movement while maintaining the forehead and chin in neutral position. |
Upper cervical flexor | ![]() | The strap is placed below the subject’s chin and the opposite end of the strap is fixed at the immobile bar located over the subject’s head at a height 1 m 50 cm. The strength sensor is placed between the subject and the immobile bar. The subject is indicated to rotate his/her chin inferiorly against the resistance of the strap. |
Lower cervical flexor | ![]() | The strap is placed on the forehead of the subject and the opposite end of the strap is fixed at the immobile bar located behind the subject’s head. The subject is indicated to rotate his/her forehead in an antero-inferior direction. |
UCE, upper cervical extensor; LCE, lower cervical extensor; UCF, upper cervical flexor; LCF, lower cervical flexor..
Table 2 . The mean values ± standard deviation of the craniovertebral angle and normalized isometric strength of the cervical muscles in the with FHP group and without FHP group.
Variables | With FHP (n = 24) | Without FHP (n = 27) | p-value |
---|---|---|---|
Craniovertebral angle (°) | 44.8 ± 2.0 | 52.5 ± 3.0 | 0.000* |
Upper cervical extensor strength (N/kg%) | 8.8 ± 3.3 | 10.6 ± 3.6 | 0.074 |
Lower cervical extensor strength (N/kg%) | 9.3 ± 3.7 | 12.7 ± 3.7 | 0.002* |
Upper cervical flexor strength (N/kg%) | 7.1 ± 2.0 | 9.4 ± 2.4 | 0.001* |
Lower cervical flexor strength (N/kg%) | 5.7 ± 1.8 | 5.7 ± 1.7 | 0.977 |
Upper cervical F/E ratio | 0.87 ± 0.27 | 0.92 ± 0.23 | 0.471 |
Lower cervical F/E ratio | 0.67 ± 0.27 | 0.48 ± 0.15 | 0.004* |
FHP, forward head posture; N, Newton; F/E, flexor/extensor. *Represents significant differences..