• Physical Therapy Rehabilitation Science
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• v.6 no.1
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• pp.33-38
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• 2017

Objective: This study tried to examine the muscle activity of the neck and trunk according to head posture changes during use of laptops. Design: Cross-sectional study. Methods: This study included nineteen young men and women. All subjects maintained each posture while practice typing on laptops for ten minutes with a 5-minute break between each posture. For the neutral head posture, the subjects practiced typing while pulling their chins down towards the Adam's apple and were able to look at their knees while having their external auditory meatus, acromion, and greater trochanter vertical to the ground. For the natural head posture, they practiced typing while balancing their posture between extension and flexion of the cervical vertebrae by themselves without any guidelines. While a forward head posture was created by having their heads face the front horizontal to the rope hanging from the ceiling, they practiced typing with their external auditory meatus located in the place which was 5 cm in front of the vertical plane. The subjects used general word process but practiced typing with accuracy and high speed. Muscle activities were randomly measured using surface electromyography according to each postures. Results: The research result had found that muscle activity with the natural head posture was more significantly reduced than that of the forward head posture in the sternocleidomastoid muscle, upper trapezius, cervical vertebral spinae, and thoracic vertebrae spinae muscles (p<0.05) and that the neutral head posture was more significantly reduced than that of forward head posture in the upper trapezius, cervical vertebral spinae, and thoracic vertebrae spinae muscle activity (p<0.05) with significant increases in lumbar spinae muscle activity (p<0.05). Also, muscle activity with the neutral head posture significantly increased more in the sternocleidomastoid muscle and lumbar spinae than that of the natural posture (p<0.05). Conclusions: Our study results suggest that in order to prevent musculoskeletal pain, the neutral head posture with use of laptops is effective in reducing load to the shoulders and vitalizing the postural muscles.

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.769-776
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• 2001

This study were to review of muscle imbalance of head, cervical and shoulder region. Head, cervical and shoulder region is a complicated mechanical unit. interconnected by numerous soft tissue links. These links, or articulation are functionaly and reflexly interdependent on one another. The line of gravity falls anterior to the transverse axis of rotation for flexion and extension of the head and creates a flexion moment. which tends to tut the head forward, is counteracted by tension in the tectorial membrane, and ligamentum nuchae, and by activity of the neck extensors. Therefore, the flexion moment equilibrate with the extension moment. Changing of the equilibrium will make mid cervical straight. It will make forward head posture(FHP) also. FHP makes imbalance of suboccipital muscles, suprahyoid muscles and infrahyoid muscles. It has some relationship with temporomandibular joint, spine and equilibrium of pelvis.

• 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.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.315-327
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• 1992

The purpose of this study was to evaluate the utilization of the orthopantomograph as a diagnostic aid to observe maxillary sinus and adjacent structures. For achieving this goal. the lead plates were attached to the five walls of the maxillary sinus of a human dry skull. The dry skull was placed in fourteen different positions; standard. 20mm forward. 20mm backward. 10 degree upward. 10 degree downward. 20mm lateral. forward & upward, forward & downward. forward & lateral. backward & upward. backward & downward, backward & lateral. upward & lateral. downward & lateral position. The obtained results were as follows: 1. The image of the medial wall was observed very differently according to the head positions. 2. The image of the anterior wall was observed at medial third to half of the maxillary sinus in each head position. 3. the image of the posterior wall was always observed at lateral third of the maxillary sinus in all head positions and more obviously in the downward-lateral position. 4. The image of the superior wall was observed at the inferior third to half of the orbit in each head position. 5. The image of the inferior wall was always observed at the inferior third of maxillary sinus in all head positions and observed more obviously in the standard and downward-lateral positions. 6. The images of the zygomatic process. zygomatic arch and zygomaticotemporal suture were observed very well in the downward-lateral position.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.2
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• pp.15-20
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• 2014

Objective: The purpose of this study was to investigate the effects of sling exercise on the cervical lordotic angle, craniovertebral angle, and head rotation angle among adolescents in the forward head posture. Methods: The subjects include 22 adolescents that recorded a mild level or higher on the posture evaluation index by New York State. They were randomly divided to the hand exercise group (n=11) and the control group (n=11). The former group participated in the sling exercise program three times a week over four weeks in total with each session lasting 60 minutes, whereas the latter group was not included in the program. The cervical lordotic angle, craniovertebral angle, and head rotation angle were measured before and after the intervention. Results: The study compared the cervical lordotic angle between the two groups before and after sling exercise and found that the sling exercise group made an increase of $7.36^{\circ}$ from $21.91^{\circ}$ to $29.27^{\circ}$ after the intervention(p<.05). As for the comparison results of the craniovertebral angle, the sling exercise group made an increase of $5.64^{\circ}$ from $48.91^{\circ}$ to $54.55^{\circ}$ after the intervention (p<.05). As for the comparison results of the cranial-rotation angle, the sling exercise group made an decrease of $-7.73^{\circ}$ from $148.82^{\circ}$ to $141.09^{\circ}$ after the intervention (p<.05). The control group showed no differences before and after the intervention (p>.05). Conclusion: Those findings indicate that the application of sling exercise in the forward head posture can be a good program to maintain the right posture and improve or prevent an abnormal posture and raise a need for more clinical applications and ongoing researches.

• 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.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.141-152
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• 1984

The author analysed the bone changes, the positional relationships between condylar head and articular fossa, and the interrelationship between the bone changes and the abnormal position of condylar head, from 1,036 radiographs of 259 patients with temporomandibular joint arthrosis, which were obtained by the oblique-lateral transcranial projection and orthopantomograms. The results were as follows: 1. Among the radiographic bone changes of the temporomandibular joint arthrosis, deformity was 36.90%(217 case), sclerosis 34.18% (20 cases), errosive chang 25.85% (152 cases) and marginal proliferation 3.06% (18 cases) respectively. 2. In the positional changes between condylar head and articular fossa, the downward positioning of condylar head in centric occlusion was most frequent(36.90%), of which frequency was signifiantly higher than forward positioning (11.22%) and backward positioning(4.76%) in same condition. Also, radiographs showed that the enlargement of articular space showed higher frequency than its narrowing. In the opening position of mouth, the restricted movement of condylar head within articular fossa was most frequent(35.03%). The forward positioning and the downward positioning was 15.65% and 9.52% respectively. Also, radiographs revealed that the incomplete movement or no positional change of condylar head was most frequent. 3. In the interrelationship between bone changes and abnormal position of condylar head, deformity was 42.79% in the cases of downward positioning of condylar head in centric occlusion and 37.50% in those of normal positioning of condylar head in same condition. This revealed that deformity was most frequent bone change in above condylar positionings. However, erossive change was 34.62% in the cases of downward positioning of condylar head in centric occlusion and 33.33% in those of forward positioning. In opening position of condylar head, and deformity in the cases of normal positioning, forward positioning and downward positioning of condylar head was 38.38%, 36.96% and 44.64% respectively. 4. Bone changes of condylar head was 47.11%, articular eminence 41.50% and articular fossa 11.39% respectively. This revealed that the frequencies of bone changes. were higher in the projected portion of bony structures of temporomandibular joint than their depressed portions. On the otherhand, in the bone changes of condylar head, deformity was 59.57% which was the most frequent. In the bone changes of articular eminence and articular fossa, however, sclersis was 41.39% and 65.67% respectively, which was the most frequent in those portions.

• Physical Therapy Korea
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• v.12 no.4
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• pp.41-47
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• 2005

The purpose of this study was to determine the intra-rater and inter-rater reliability of various forward head posture measurements. Ten healthy adults (age, $20.4{\pm}2.2$ yrs; height, $164.0{\pm}5.5$ cm; weight, $58.7{\pm}7.3$ kg) participated in the study. They were free of injury and neurologic deficits in the upper extremities and neck at the time of testing. The subjects were asked to perform head forward posture by under the guidance of physical therapists. Markers were placed on the C7 spinous process, mastoid process, tragus of the ear, outer canthus, and forehead. Measurement 1 for forward head posture assessment was measured as the angle between the horizontal line through C7 and the line connecting the C7 spinous process with the tragus of the ear. Measurement 2 was measured as the angle between the C7 spinous process, the mastoid process and the outer canthus. Measurement 3 was measured as two kinds of angles the HT (head tilt) angle is between the line from the midpoint of forehead to the tragus line and Y-axis at the tragus point. The NF (neck flexion) angle is between the line from the tragus to the C7 line and the Y-axis at the C7. Intra-rater, inter-rater reliability and coefficient of variation was assessed by comparing the measured values from three kinds of measurements of forward head posture. The intra-rater reliability was indicated by intraclass correlation coefficients [ICC(1,1)] and inter-rater reliability was shown by intraclass correlation coefficients [ICC(3,k)]. The results of study were as follows: ICC(1,1) values for intra-rater reliability of three measurements were in the 'excellent' category. ICC(3,k) values for inter-rater reliability of three measurements were also in the 'excellent' category. The coefficient of variation of method 2 had a lower value than method 1 and method 3. This data means that the measured value of method 2 was less scattered. Further research is needed to determine whether the validity of all measurements is revealed in the 'excellent' category.

• Journal of International Academy of Physical Therapy Research
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• v.6 no.2
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• pp.871-877
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• 2015

This research was conducted to investigate the effect of continuous antagonistic muscle strengthening exercise and Evjenth-Hamberg stretching on the pulmonary function of university students with abnormal transformation of forward head posture(FHP). The results of study subject to the continuous antagonistic muscle strengthening(CAS) group(n=10) and Evjenth- Hamberg stretching(EHS) group(n=10) that was conducted 3 times a week for 6 weeks are as follow. FVC, IVC, and MVV all were shown to be significant in the pre post comparison between the CAS group and EHS group(p<.05), and significant difference was shown for MW between the two groups(p<.05) in which the CAS group showed better effect. Based on the results above, it is considered that combining continuous antagonistic muscle strengthening exercise has better effect on pulmonary function compared to application of only Evjenth-Hamberg stretching.

• Journal of International Academy of Physical Therapy Research
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• v.4 no.2
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• pp.633-639
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• 2013

This study aims to reveal the impact of continuous antagonist strengthening(CAS) and Evjenth-Hamberg stretching(EHS) on the cervical mobility in the university students with abnormal transformation of forward head posture(FHP). Our experiment was conducted 3 times a week for 6 weeks in a total of 20 individuals : continuous antagonist strengthening(CAS) group(n=10) & Evjenth-Hamberg stretching(EHS) group(n=10). In a pre and post comparison, both CAS group and EHS group appeared significantly in mSBI and SBA(p<.05) and the two-group comparison showed a significant difference(p<.05) : CAS group showed better effects. Thus, it is considered that the combined use with continuous antagonist strengthening(CAS) had better effects for cervical mobility than Evjenth-Hamberg stretching(EHS) alone.