• Journal of Korean Physical Therapy Science
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• v.30 no.3
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• pp.23-30
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• 2023

Background: Flexion of cervical and lumbar joints is required when viewing a smartphone screen. Thus, these joints are overused, together with the surrounding joints and muscles. Long-term use of smartphones will cause changes in cervical and lumbar posture. The effect on forward head posture will vary, depending on the angle of cervical flexion start position in relation to the smartphone. This study investigated how forward head posture changes over time when using a smartphone at 20° and 40° cervical flexion start positions. Design: Cross-sectional study. Methods: Twenty-five subjects with a forward head posture angle of 35° or less participated in the study. A Forward Head Posture app on the participants' smartphones measured forward head posture 5 and 10 minutes after watching videos on their smartphones. Cervical range of motion was used to set a smartphone watching start posture of 20° and 40° of cervical flexion. Results: There was no significant difference in forward head posture, irrespective of cervical flexion start position, but the angle of forward head posture increased more at cervical flexion of 40° than at cervical flexion of 20°. There was no significant difference in what according to smartphone video viewing times, but the angle of forward head posture increased over time. Conclusion: An increase in forward head posture over time with smartphone usage poses a potential risk of neck and shoulder pain. Therefore, smartphone users should avoid prolonged screen time.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.23 no.1
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• pp.43-51
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• 2017

Background: This study was carried out to compare the effects of shoulder stabilization exercise and thoracic extension exercise including deep neck flexor exercise on posture and pain targeting physical therapists and occupational therapists with forward head posture. Methods: A total of 30 physical therapists and occupational therapists (15 males, 15 females), who are working in the nursing hospital at Daejeon, were randomly divided into a shoulder stabilization group (n=10), a thoracic extension exercise (n=10), and a control group (n=10), and 3 times were carried out for 8 weeks. Results: In the results of all measurements, 2 groups except for the control group showed a significant change in the recovery of forward head posture, and the should stabilization exercise group showed a relatively superior effect compared to the thoracic extension exercise group. Conclusions: These results of a study will be a basic data for the development of the forward head posture exercise therapy program.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.3
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• pp.1-8
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• 2015

Purpose : The purpose of this study was to find out the effect of shoulder exercise program for improving forward head posture. Method : Subjects were divided into two groups. The experimental group(15 people) participated in strength exercise and stretching exercise, three times every week, during 4 weeks. And the control group(the other 15 people) didn't participate in exercises. Exercise program was composed of strength exercise of middle and lower trapezius and stretching exercise of levator scapulae and upper trapezius. And then we measured cervical alignment with GPS and muscular activity by EMG. Result : The results of this study were as follows; 1. After the intervention, experimental group was significantly decreased in cervical alignment than control group(p<.05). 2. After the intervention, experimental group was significantly increased in middle lower trapezius musclar activity than control group(p<.05). Conclusion : Strength exercise of middle and lower trapezius and stretching exercise of levator scapulae and upper trapezius were considered a efficient for improving forward head posture.

• The Journal of Korean Physical Therapy
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• v.26 no.3
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• pp.140-146
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• 2014

Purpose: Differences in scapular kinematics and muscle activity appear in the forward head and rounded shoulder posture (FHRSP). Thus, the aim of this study was to investigate the following effects according to different postures on scapular kinematics and muscle activity around scapular region in individuals with and without FHRSP during overhead reaching task. Methods: Thirty pain-free subjects with/without FHRSP participated in this study. All subjects were positioned into three positions: habitual head posture (HHP), self-perceived ideal head posture (SIHP) and therapist-perceived neutral head posture (TNHP). Muscle activities of upper trapezius (UT), lower trapezius (LT) and serratus anterior (SA) were measured during overhead reaching task. Results: Muscle activity of trapezius muscle (UT and LT) during HHP was significantly higher than SIHP and TNHP in FHRSP group (p<0.05), but there was no difference between SIHP and TNHP. SA also significantly increased muscle activity in HHP more than SIHP and TNHP in FHRSP group (p<0.05), but there was no significant difference between SIHP and TNHP. In Non-FHRSP group, although there was a tendency of different muscle activities among three postures, it was not statistically significant. Conclusion: This result demonstrates that muscle activity associated with overhead reaching task is increased in HHP which affects the scapular kinematics and SIHP contributes changed scapular kinematics and proper recruitment of muscle activity in FHRSP similarly to TNHP.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.4
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• pp.265-272
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• 2019

Purpose : Excessive computer use frequently results in musculoskeletal disorders of the neck and shoulder such as forward head posture (FHP). The purpose of this study was to investigate effects of neck and shoulder exercise program on spino-pelvic alignment and the correlation between change in head and neck posture and spino-pelvic alignment in FHP. Methods : The study included 44 participants with FHP. The participants performed the exercise for correction of FHP 2-3 times a week for 4 weeks. We examined whole spine X-ray images in the lateral standing position with both arms crossed. We measured anterior head translation distance (AHT), craniovertebral angle (CVA), cervical lordosis (CL), thoracic kyphosis (TK), lumbosacral lordosis (LSL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI) of the subjects. The association between change in AHT and each spino-pelvic parameter was also subjected to Pearson's correlation coefficient analysis. Results : There were statistically significant differences before and after exercise in the parameters of AHT, CVA, and SS (p<.05). Significant negative correlation was observed between the change in AHT and CVA (r=-.768, p<.001), and CL (r=-.388, p<.05). There was significant positive correlation between the change in AHT and SS (r=.328, p<.05), and PI (r=.333, p<.05). However, no significant correlation was observed in change in AHT with that of TK, LSL, and PT. Conclusion : Based on the above results, we conclude that there is a relationship between change in AHT, which is a parameter associated with forward displacement of the head, and that of CVA, CL, SS, and PI after exercise in cases of FHP.

• Physical Therapy Korea
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• v.13 no.1
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• pp.9-15
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• 2006

Work-related musculoskeletal disorder has been associated with long hours of computer work and prolonged periods of static posture. In clinical settings, postural correction is a common treatment approach for individuals with neck, shoulder, and back pain. This study was designed to identify the effect of Forward Head Posture Correctional Device during computer work. Twelve healthy adults (mean age, 27.4 yrs; mean height, 165.0cm mean weight, 65.8 kg) participated in the study. They had no medical history of neurological or surgical problems with their upper extremity. The subjects were asked to perform Head Forward Posture under the guidance of physical therapists and the measured angles were analyzed using a 3-D motion analysis system. Markers were placed on the C7 spinous process, tragus of the ear and forward head angle was between the line from the tragus to the C7 line and the Y-axis at the C7. The statistical significance of difference between, "without" and "with" correctional device was tested by paired t-test. A level of significance was set at ${\alpha}$=.05. In comparison of the computer work between "without" and "with" correctional device, Forward Head Angle was showed significant difference (p<.05). In conclusion, the range of Forward Head Angle was significantly decreased during computer work with the correctional device. Further research is needed to understand the nature of motor control problems in deep muscles in patients with neck, shoulder, and back pain.

• Physical Therapy Korea
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• v.30 no.1
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• pp.23-31
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• 2023

Background: Several factors contribute to shoulder pain, including abnormal neck posture, repeated use of the upper limbs, work involving raising the upper limbs above the head, and the effects of vibration. However, previous study has reported that constant vibration exposure could impact improvement of the stability on joints related with muscle recruitment and activation. For this difference reason, we need to verify for the complex study of relationship with repetitive upper limb movements, poor head posture, and constant vibration exposure. Objects: Our study was made to investigate the influence of vibration exposure on the shoulder muscle activity during forward-head and over-head tasks with isometric shoulder flexion. Methods: In a total of 22 healthy subjects, surface electromyography (EMG) data were collected from shoulder muscles (upper/lower trapezius, serratus anterior, and lumbar erector spinae) on tasks (neutral-head task [NHT], forward-head task [FHT], and over-head task [OHT]) with and without vibration exposure. Results: In all tasks, the EMG data of the upper trapezius and serratus anterior significantly increased with vibration exposure (p < 0.05). Furthermore, the EMG data of the lumbar erector spinae significantly increased with vibration exposure in the NHT and FHT (p < 0.05). Conclusion: We suggest that continuous vibration exposure during the use of hand-held tools in the tasks could be associated with harmful effects in the workplace. Lastly, we clinically need to examine the guidelines regarding the optimal posture and vibration exposure.

• The Journal of Korean Physical Therapy
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• v.30 no.2
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• pp.47-53
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• 2018

Purpose: To find the effect of visual feedback of head angle with using a mobile posture-aware system on craniocervical angle and neck and shoulder muscles fatigue for preventing or decreasing the forward head posture. Methods: Twenty-four healthy young adults in Chungbuk to participate in this study. The subjects started to watch a movie clip for 10 minutes with visual feedback in $0^{\circ}$, $30^{\circ}$, and $60^{\circ}$ of head angles. During the task, surface electromyography (EMG) was used to collect data from the upper trapezius (UT), sternocleidomasetoid muscle (SCM), cervical erecter spinae (CES) during watching the smartphone. Craniocervical angles were measured using a sagittal-view photograph of the subject in a sitting posture. A one-way repeated analysis of variance with a significant level of 0.05 used for statistical analysis. Results: Craniocervical angle with $0^{\circ}$ visual feedback was significantly greater than $30^{\circ}$ and $60^{\circ}$. Craniocervical angle with $30^{\circ}$ visual feedback was significantly greater than $60^{\circ}$. In addition, MDF of UT muscles in $0^{\circ}$ and $30^{\circ}$ of visual feedback was significantly greater than $60^{\circ}$. Conclusion: We concluded that $0^{\circ}$ visual feedback of head angle with using a mobile posture-aware system would be beneficial to prevent or decrease forward head posture during watching a smartphone. We also could recommend using of $30^{\circ}$ visual feedback in case of caring UT muscle fatigue primarily.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.227-235
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• 2019

The purpose of this study was to investigate the effects of cervical vertebral height and shoulder stabilization on anterior head posture in people with turtle neck. The subjects of this study consisted of normal and healthy people with 30 turtle necks. Subjects were randomly assigned to shoulder stabilization exercise and cervical vertebrae exercise (30 men, 15 men and 15 women, height: $168.67{\pm}6.51$, $22.33{\pm}8.27$, $65.03{\pm}11.98$, and $28.66{\pm}1.91$), In the experimental group, shoulder stabilization exercise and cervical spine exercise were performed for 4 weeks. Deep neck flexor, leavator scapular, upper trapezius, rhomboid, and lower trapezius showed significant differences in shoulder stabilization and cervical vertebrae before and after the experiment. As a result, the CVA value decreased significantly and the muscle activity value increased significantly when exercise and Mckenzie program were applied. These results show that exercise and Mckenzie programs have a positive effect on turtle neck improvement.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.3
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• pp.173-180
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• 2020

Purpose : The aim of this study was to assess the intra- and inter-rater reliability and validity of measurements of head, neck, and pelvis posture using a mobile application in subjects with forward head posture. Methods : Forty-eight volunteers (22 men, 26 women) participated in this study. Two raters independently examined whole body picture images in a lateral standing posture with arms crossed using a CA-Smart Posture Reminder (CA-SPR), and a rater took and calculated posture images twice to assess reliability. We measured five parameters: craniovertebral angle 1 (CVA1), anterior shoulder translation (AST), pelvic tilt (PT), knee angle (KA), and ankle angle (AA) in the subject's sagittal plane using CA-SPR. We examined whole spine X-ray images in the same position to assess validity. We measured four variables in the subjects: CVA2, translation distance (AHT), anterior pelvic plane (APP), and sacral slope (SS). The intra- and inter-rater reliability were calculated using the intraclass correlation coefficient (ICC). Convergent validity was calculated using Pearson's correlation coefficient. Results : The intra-rater reliability (ICC=.889 -.989) and inter-rater reliability (ICC=.800 -.980) were excellent for all variables measured using CA-SPR. The variables measured using CA-SPR and X-ray were significantly positively correlated (r=.623, p<.01). However, the correlation of the variables in the pelvis was not statistically significant. Conclusion : This study shows that a mobile application (CA-SPR) is a useful tool for measuring head and neck posture in subjects with forward head posture. However, further study is needed to measure pelvic variables when using a mobile application.