• The Journal of Korean Physical Therapy
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• v.31 no.1
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• pp.1-6
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• 2019

Purpose: This paper proposes proper and effective neck exercises by comparing the deep and superficial cervical flexor muscle activities and thickness according to the pressure level during cranio-cervical flexion exercises between a normal posture group and forward head posture group. Methods: A total of 20 subjects (8 males and 12 females) without neck pain and disabilities were selected. The subjects' craniovertebral angles were measured; they were divided into a normal posture and a forward head posture group. During cranio-cervical flexion exercises, the thickness of the deep cervical flexor neck muscle and the activity of the surface neck muscles were measured using ultrasound and EMG. Results: The results showed that the thickening of the deep cervical flexor was increased significantly to 28 and 30 mmHg in the forward head posture group. The sternocleidomastoid muscle activity increased significantly to 24, 26, 28, and 30 mmHg in the forward head posture group. The anterior scalene muscle activity increased significantly to 26, 28, and 30mmHg in the forward head posture group. A significant difference of 26, 28, and 30 mmHg in the sternocleidomastoid and anterior scalene muscles was observed between two groups. Conclusion: To prevent a forward head posture and maintain proper cervical curve alignment, the use of the superficial cervical flexor muscles must be minimized. In addition, to perform a cranio-cervical flexion exercises to effectively activate the deep cervical flexor muscles, 28 and 30 mmHg for normal posture adults and 28 mmHg for adults with forward head postures are recommended.

• The Journal of Korean Physical Therapy
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• v.27 no.1
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• pp.50-54
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• 2015

Purpose: The purpose of this study is to investigate differences of cervical flexor muscle thickness (i.e., sternocleidomastoid muscle and deep cervical flexor muscles) depending on levels of pressure bio-feedback unit and eye directions during cranial-cervical flexor exercise in healthy subjects. Methods: A total of 30 subjects (12 males and 18 females) who had no medical history related to musculoskeletal and neurological disorders were enrolled in this study. They were instructed to perform cranial-cervical flexion exercise with adjustment of five different pressures (i.e., 22 mmHg, 24 mmHg, 26 mmHg, 28 mmHg, and 30 mmHg) using a pressure biofeedback unit, according to three different eye directions (i.e., $0^{\circ}$, $20^{\circ}C$, and $40^{\circ}C$). Muscle thickness of sternocleidomastoid muscle and deep cervical flexor muscles was measured according to pressure levels and eye directions using ultrasonography. Results: In results of muscle thickness in sternocleidomastoid muscle and deep cervical flexor muscles, the thickness of those muscles was gradually increased compared to the baseline pressure level (22 mmHg), as levels in the pressure biofeedback unit during cranial-cervical flexion exercise were increasing. In addition, at the same pressure levels, muscle thickness was increased depending on ascending eye direction. Conclusion: Our findings showed that muscle thickness of sternocleidomastoid muscle and deep cervical flexor muscles was generally increased during cranial-cervical flexion exercise, according to increase of eye directions and pressure levels. Therefore, we suggested that lower eye direction could induce more effective muscle activity than the upper eye direction in the same environment during cranial-cervical flexion exercise.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.4
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• pp.497-504
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• 2011

Purpose : Chronic cervical pain is a common source of disability in society. There has been no research regarding the amount of pressure for the deep cervical flexors during cranio-cervical flexion exercise (CCFE). The purpose of this study is to determine optimal pressure levels to facilitate deep cervical muscles (longus colli & longus capitis) during cranio-cervical flexion exercise, using ultrasound measurement of the muscles. Methods : Using a cross-sectional design, the study was performed in an experimental group of 19 subjects (7 men, 12 women) with no cervical pain. Participants were instructed to perform the CCFE, and during the five incremental stages of the test, changes in thickness, as compared to resting baseline values, were measured using ultrasonography for sternocleidomastoid muscle (SCM) and deep cervical muscles (DCF). Results : Both DCF and SCM muscles demonstrated an increase in recruitment with each progressive phase of the test. In comparing the different pressure increments, the most significant changes found in DCF thickness were between phase 2 and phase 3 (p<.05). However no differences were found between pressure increments for SCM thickness (p>.05). Conclusion : The results suggest 26 mm Hg as the optimal pressure level during cranio-cervical flexion exercise for facilitation of deep cervical flexor.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.2
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• pp.189-195
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• 2019

Purpose : The purpose of this study was to investigate the effects of chin tuck exercise (CTE) on the craniovertebral angle (CVA), strength and endurance of deep cervical flexor (DCF) muscles in subjects with forward head posture(FHP). This study was performed on 30 subjects with FHP. Method : Thirty subjects were divided into two groups; modified CTE (n=15), conventional CTE (n=15). Both of the group performed the exercise 4 times a week for 6 weeks. The subjects performed CTE in two different methods; modified CTE, with device designed that help keep cervical lordois curve, and coventional CTE, without using device. The CVA was measured using Image software version. A pressure biofeedback unit was used to measure the strength and endurance of the DCF muscles. The data was analyzed by the paired t-test for comparing before and after changes of variables in each group and the independent t-test for comparing the between groups. Result : There was statistically significant difference of before and after strength and endurance of DCF muscles in modified CTE (p<0.05). There was statistically significant difference of before and after only endurance of DCF muscles in conventional CTE (p<0.05). There was statistically significant difference of between the two group in strength of DCF muscles (p<0.05). Conclusion : Muscle strength to stabilize the spine plays an important role in maintaining a good posture. Therefore, we suggest that the application of CTE with a device designed to maintain the lordotic curvature in the neck is likely to yield better outcomes in FHP subjects in future studies.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.4
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• pp.117-124
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• 2021

PURPOSE: This study examined the effect of muscle thickness of the deep cervical flexor muscle, muscle tonicity, and muscle fatigue of the superficial cervical flexor muscle by applying a functional latex pillow to patients with chronic cervical pain. METHODS: An experimental group using a functional latex pillow and a control group using a general pillow were assigned randomly to 30 people. Each pillow was applied in a comfortable lying position in the experimental group and control group. The deep cervical flexor muscle thickness was measured in the longus colli and longus capitus using ultrasonography. The muscle tonicity and muscle fatigue of the superficial cervical flexor muscle were measured separately in the sternocleidomastoid muscle using a myotonometer and electromyography. RESULTS: In the experimental group(functional latex pillow), the muscle tonicity of the superficial cervical flexor muscle like the sternocleidomastoid muscle was significantly lower than that of the control group (general pillow)(p < .01). CONCLUSION: This study suggests that the functional latex pillow may effectively reduce the muscle tonicity of the sternocleidomastoid muscle, which is the superficial cervical muscle, in patients with chronic cervical pain. On the other hand, it was not effective on the muscle thickness of the deep cervical flexor muscle and muscle fatigue of the superficial cervical flexor muscles.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.21 no.2
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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.

• Physical Therapy Korea
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• v.25 no.2
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• pp.44-52
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• 2018

Background: The deep cervical flexor (DCF) muscles have a crucial role in the management of neck pain. For preventing neck pain by activation of the DCF, craniocervical flexion (CCF) is an effective exercise. However, sternocleidomastoid (SCM) muscle is considered to affect negatively the activation of the DCF. SCM muscle which is an accessory muscle for respiration is activated differently depending on types of breathing patterns. It's not certain that breathing patterns affect the SCM and DCF muscles thickness during CCF exercise. Objects: The purpose of this study was to investigate the influence of breathing patterns on the SCM and DCF muscles thickness during CCF exercise. Methods: Forty-five subjects participated in this study, and they were classified according to their breathing pattern, as follows: costodiaphragmatic breathing (CDB) and upper costal breathing (UCB) groups. Ultrasonographic imaging of the SCM and DCF muscles was performed during five incremental levels of CCF during tidal breathing and expiration. Results: There was a significant interaction between the breathing pattern and the phase of CCF for percentage of SCM muscle thickness changes (p<.05). In phase 1 CCF, a percentage of SCM muscle thickness changes was increased in the UCB group than in the CDB group (p<.05). There was an increase in DCF muscles thickness with each additional CCF phase (p<.05). Conclusion: Recruitment of SCM muscle was increased in the UCB group while performing CCF with a low intensity. There were no significant differences on DCF recruitment between the breathing pattern groups. Higher CCF exercise intensities elicited a higher DCF recruitment.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.25-31
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• 2007

The purpose of this study was to investigate the strength and endurance of the deep neck flexor muscles in individuals with work-related neck pain. Subjects consisted of two groups: twenty industrial workers with neck pain and twenty age-matched healthy subjects. To evaluate the strength and endurance of deep cervical flexors, maximum voluntary contractile strength (MVCS) and a sustained time at sub-maximal voluntary contractile strength (SMVCS) (80% and 50% of MVCS) were measured using a pressure biofeedback unit and a stop watch in supine. The MVCS of deep neck flexor muscles was 29.67${\pm}$4.56 in neck pain group and 54.27${\pm}$6.78㎜Hg in normal group. The sustained time at 80% SMVCS was 12.42${\pm}$2.64 seconds and 55.12${\pm}$12.76 seconds in the groups with and without neck pain. The sustained time at 50% SMVCS was 25.40±5.88 seconds and 109.70${\pm}$31.50 seconds in the groups with and without neck pain. The difference of the lower jaw position was 16.75${\pm}$3.57㎜ and 23.03${\pm}$2.51㎜. The MVCS, endurance at the two sub-maximal levels and the difference of the lower jaw position were significantly greater in the group without neck pain than with neck pain (p$<$0.05). The findings indicate that the maximal strength and endurance of the deep neck flexors were decreased in the workers with neck pain compared to those without neck pain. Therefore, it is necessary to include strengthening and endurance exercises of the deep neck flexor muscles in therapeutic program of work-related musculoskeletal disorders involving neck pain.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.302-308
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• 2020

Objective: The endurance and strength of deep neck flexor (DNF) muscles have a major role on the function and stability of the cervical spine. In recent years, there has been a lack of research that have investigated the muscle tone of the superficial neck muscles. The purpose of this study was to examine the relationship of between contraction ratio of the DNF and sternocleidomastoid (SCM) muscles, DNF endurance, and muscle tension of the neck muscles. Design: Cross-sectional study. Methods: Forty-seven subjects (male=20, female=27) participated in this study. The muscle tone of the upper trapezius (UT), SCM, and suboccipital (SO) muscle was measured using a contact soft tissue tone-measuring instrument. For the contraction ratio of the SCM and longus colli muscle, the thickness of the relaxation and maximum contraction state of the SCM and longus colli muscles were assessed using a diagnostic ultrasound measuring instrument and a pressure biofeedback unit. The deep neck flexor endurance test (DNFET) was performed in a cranio-cervical flexion posture. The correlations between the measured variables were investigated. Results: The relationship between the DNFET and SO tone showed a significant negative correlation (p<0.05). The relationship between the DNFET and contraction ratio showed a significant positive correlation (p<0.01). There was no significant correlation between the DNFET and SCM and UT tone. Conclusions: This study confirmed that there is a relationship between DNF endurance, DNF activation, and SO tone. The information on the results of this study may be used as a reference that can be actively applied in the clinical environment.

• Journal of the Ergonomics Society of Korea
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• v.27 no.4
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• pp.59-64
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• 2008

The aims of this study were to compare and analyze two types of deep cervical flexion exercises, craniocervical flexion and cervical flexion, and to ascertain their relative effects on neck and shoulder pain and functional improvement. The participants of the study were individuals who work in sedentary jobs in an office environment. 54 appropriate subjects were chosen and randomly divided into two groups: one group underwent a craniocervical flexion exercise program and the other a cervical flexion exercise program. The six week exercise program consisted of home exercises performed by each subject five times a week and education once a week. Neck-shoulder pain, muscle strengthening, cervical alignment were measured prior to commencement of the exercise programs and again after six weeks. At completion of the six week, both exercise programs decreased neck pain (p<.05). Forward head postures were reduced, and the craniocervical flexion exercise program was more effective in reducing forward head posture (p<.05). The maximum muscle strength and 50% of maximum muscle strength maintaining time of the deep cervical flexor muscles were significantly increased. There were no significant changes of the cervical lordotic curve. The results of this study showed deep cervical flexion exercise was effective in the treatment of neck and shoulder pain, however craniocervical flexion exercise was more effective than cervical flexion exercise.