• 대한물리의학회지
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• 제11권3호
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• pp.35-39
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• 2016

PURPOSE: The purpose of this study was to examine changes in the neck flexion angle according to posture while using a smartphone and the duration of smartphone usage. METHODS: The subjects in this study were 16 healthy young students in their 20s. The subjects wore a cervical range of motion instrument. They were instructed to use a smartphone while standing, sitting on a chair, and sitting on the floor. In all postures, they could use the smartphone and use their arms freely while keeping their back connected to the wall or the back of the chair. When sitting on the floor, they assumed a cross-legged position. The neck flexion angle was measured at zero, three, six, and nine minutes for each posture. RESULTS: Neck flexion is affected by the posture while using a smartphone (p<.05). Neck flexion in the standing position is larger than that in the sitting on the floor position. Neck flexion was affected by smartphone usage duration (p<.05). In general, as usage time increases, the neck flexion angle increases as well. CONCLUSION: This study suggests that using smartphone in the standing position and for a short period of time is a method to reduce the neck flexion angle.

• The Journal of Korean Physical Therapy
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• 제35권5호
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• pp.151-155
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• 2023

Purpose: This study examined the effect of the degree of neck flexion on the muscle activity of the upper trapezius and sternocleidomastoid muscles in the sitting position. Methods: Twenty-five healthy young adults participated in this study. The study was designed to compare the muscle activity of the upper trapezius and sternocleidomastoid muscles according to the neck flexion angle under the three conditions (neutral position, 15° neck flexion, and 45° neck flexion) in the sitting position. During the neck position of three conditions in sitting, the electromyography (EMG) data (% maximum voluntary isometric contraction) of the muscles were recorded using a wireless surface EMG system. Results: The muscle activity of the upper trapezius muscle and the sternocleidomastoid muscles showed a significant difference according to the three-neck position conditions (p<0.05), and in the post-hoc test results, both muscles showed significant differences between the neutral position and 15° flexion, the neutral position and 45° flexion, and the 15° flexion and 45° flexion, respectively. Conclusion: The load on the muscles around the neck and shoulders increased as the neck flexion angle increased. This suggests that performing various daily activities and tasks with the neck as neutral as possible can prevent muscle fatigue or musculoskeletal disorders.

• The Journal of Korean Physical Therapy
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• 제23권1호
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• pp.29-35
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• 2011

Purpose: The purpose of this study was to identify the effect of neck exercises on neck-shoulder posture and pain of high school students with neck disorders. Methods: Twenty seven subjects were randomly assigned to one of 3 groups a craniocervical flexion training group (CCFT), a neck strengthening exercise group (ST), and a basic stretching exercise group (CG). CCFT and ST exercised five times a week for eight weeks under the researcher's guidance. The control group performed basic stretching exercises. Diagnostic radiologic equipment was used for the measurement of neck-shoulder posture. Neck disability index, and numeric rating scales were used. Results: The CCFT showed a significant pre-post treatment difference on measures of neck flexion angle and forward shoulder angle changes compared to the ST and CG groups (p<0.05). The CCFT group also showed a significantly greater improvement on the neck disability index and numeric rating scales changes than the ST and CG groups (p<0.01). Conclusion: Because CCFT decreases neck flexion angle, forward shoulder angle, neck disability index, and pain in the forward head posture, it is useful for treating patients with neck disorders.

• 대한의용생체공학회:의공학회지
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• 제38권6호
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• pp.291-294
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• 2017

It is known that laptop computer stand is helpful to maintain the good posture while using laptop computer on the desk. But the quantitative validation of its effect has not been reported. Using the wearable neck posture tracker, the forward flexion angle of the neck can be measured in daily life. In this study, the forward flexion angles of the neck while using the laptop computer with and without laptop computer stand were compared. From the posture data of 10 subjects for 6 hours, the average of the forward flexion angle was 0.9 degree with laptop computer stand and 16.3 degree without laptop computer stand. As the conclusion, laptop computer stand can decrease the forward flexion angle which is known as forward head posture while using the laptop computer on the desk.

• The Journal of Korean Physical Therapy
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• 제29권4호
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• pp.158-163
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• 2017

Purpose: The purpose of this study was to investigate the relationship among pain, range of motion of the neck, neck disability index and grip strength after thoracic manipulation and cervical stabilization training in patients with chronic neck pain. Methods: In this study, twelve subjects with chronic neck pain were included. All participants had thoracic manipulation and cervical stabilization training. Intervention was conducted three times per a week, for 4 weeks. The visual analogue scale (VAS), range of motion of neck, neck disability index (NDI), as well as the grip strength before and after intervention were measured in all participants. Paired t-test was used to compare variables before and after intervention. Pearson correlation analysis was used to identify the correlations between the variables. Results: All variables after the intervention were significantly improved. There was a significant negative correlation between VAS and flexion angle of the neck (r=-0.669, p<0.05). Moreover, there was a significant positive correlation between NDI and VAS (r=0.636, p<0.05), and a significant negative correlation between NDI and flexion angle of the neck (r=-0.692, p<0.05). Conclusion: Patients with reduced pain following therapeutic intervention illustrated that there would be an improvement in the flexion angle rather than the extension angle of the neck, and that those with increased flexion angle would have less restriction of activities in daily living.

• 대한정형도수물리치료학회지
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• 제24권1호
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• pp.15-21
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• 2018

Background: The purpose of this study was to determine the effects of cervical deep muscle flexion exercise (CCFE) on craniovertebral angle, pain, and neck disability for patients with chronic neck pain Methods: The subjects of this study were randomly divided into three groups of 30 patients with chronic neck pain: rectus abodominis functional massage (n=10), cervical deep muscle flexion exercises group (n=10), and the control group(n=10). To assess visual analog scale (VAS) was used to test the neck pain, To assess neck posture was used to craniovertebral angle, VAS was used to test the neck pain, neck disability index (NDI) was used to test the neck dysfunction. All measurements were performed before and after each intervention was applied 3 times a week for 4 weeks. Results: In the results of all measurements, 2 groups except for the control group showed a significant change in the recovery of posture, neck pain, neck disability index (p<.05). Conclusions: Our results of this study showed that applying cervical deep muscle flexion exercise and rectus abodominis functional massage to patients with chronic neck pain improved cervical posture, neck pain, neck disability.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.121-122
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• 2017

본 논문에서는 목을 구부려 턱이 가슴에 닿도록 하는 굽힘과, 목을 들어 천장을 보는 것처럼 자세를 취하는 폄에 대하여 각을 측정한다. 굽힘의 각도는 $45{\sim}50^{\circ}$가 기본이며 최대의 가동 범위는 $80{\sim}90^{\circ}$이다. 폄의 각도 또한 $40^{\circ}{\sim}50^{\circ}$가 기본이며 정상은 $70^{\circ}$로 제한된다.

• 대한인간공학회지
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• 제30권5호
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• pp.637-644
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• 2011

Objective & Background: When applying various evaluation tools that analyze work posture risk through observation, accurate measurement of body flexion angle is very important. Method: This study investigated differences and appropriateness of 5 different existing reference points commonly used in the analysis of the work posture. Twenty five ergonomist and trained professionals were participated in this study. A Same flexion angle was utilized for the evaluation of risk assessment of musculoskeletal disorders using five different reference points to investigate the degree of difference between them. To investigate how different the observers' preferred flexion angle measuring methods were compared to the ISO 11226 Reference Posture, a virtual body model was constructed using the Poser 6.0 program. Six types of body flexion postures were constructed, and since neck flexion differs according to body angle, five types of neck flexion postures were constructed with the trunk bending $20^{\circ}$ forward, making up a total of 30 virtual flexion postures. Results: Results showed that the observers used personally preferred reference points instead of reference points recommend in the evaluation tools. Also the results revealed the their seems to be 6 types of flexion angle for the trunk and 11 types of measurement methods for the neck flexion angle in the form of personally preferred reference points. The results showed that a mean difference of $14^{\circ}$($4{\sim}23^{\circ}$) occurred in the trunk, and a mean difference of $20^{\circ}$($-8{\sim}51^{\circ}$) occurred in the neck. To increase accuracy when using the 5 evaluation tools in combination, the ISO 11226 standards, observers' preferred flexion posture standards, and common flexion posture standards of the evaluation tools were compared with the reference points of the 5 evaluation tools. Results showed considerable variance in angle difference for each evaluation tool. Conclusion: According to the results of this study, considering the angle difference between the flexion angle reference points of the evaluation tool and the reference points selected by the observers, it is concluded that instead of personally preferred reference points, the standardized reference points to enhance the accuracy and the objectivity. Application: The result of this study can be used as reference guide to develop the standardized reference point in the future.

• 대한물리의학회지
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• 제4권2호
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• pp.117-124
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• 2009

Purpose：The purpose of this study was to investigate of the change of the forward head posture(FHP) according to computer using time. Methods：Subjects were 30 male and 30 female. The factors of FHP were measured cranial vertical angle, cranial rotation angle, and head, upper back, neck flexion/extension angle according to computer using time. Change of FHP used to Digital Inclinometry(JTech, Dualer IQTM Dual Inclinometer). The data were collected by data logger(Logger Teknologi HB, Akarp, Sweden). Results：Cranial vertical angle, cranial rotation angle, and head, upper back, neck flexion/extension were increased according to computer using time(p<.05). But cranial vertical angle and cranial rotation angle, and head, upper back, neck flexion/extension were not significant differences between male and female group(p>.05). Conclusion：The effects of cranial vertical angle, cranial rotation angl and head, neck and upper back angle depend on the computer task time. Increased of FHP may result increased tension in posture muscles of cervical spine, resulting in a risk of musculoskeletal disorders.

• 대한정형도수물리치료학회지
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• 제21권2호
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• pp.33-37
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• 2015

Background: The purpose of this study on the effects of deep cervical flexors strengthening exercise to forward head posture and pain of neck in patients with chronic neck pain. Method: We selected 30 subjects among neck pain patients and carried out measurements. The subjects' forward head posture was measured including head tilt angle (HTA), neck flexion angle (NFA) and forward shoulder angle (FSA), neck disability index (NDI), numeric rating scale (NRS). The subjects underwent deep cervical flexors muscle strengthening with pressure bio-feedback device for 4 weeks. Then, after intervention, the subjects' forward head posture was measured again. It was performed Wilcoxon signed-ranks test for confirming the effect of deep cervical flexor muscles strengthening exercise. Results: As a result of comparison of measurements before and after intervention, we found that there were statistically significant improvement in the subjects' NDI, NRS and forward head posture including head tilt angle, neck flexion angle and forward shoulder angle. Conclusion: We concluded that deep cervical flexors strengthening exercise has the effect of alleviation of neck pain patients and is effective for forward head posture.