• Journal of Oral Medicine and Pain
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• v.40 no.3
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• pp.115-123
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• 2015

Purpose: The aim of this study was to elucidate the coordination patterns of the sternocleidomastoid and posterior cervical muscles in response to symmetrical and asymmetrical jaw functions in normal adults. Methods: Twenty-seven healthy volunteers (8 females, 19 males; mean age, $30.4{\pm}2.5$ years) participated in this study. Surface electromyography (EMG) was used to record activities in the masseter, suprahyoid, sternocleidomastoid, and posterior cervical muscles at rest and during maximum tooth clenching, biting of a cotton roll with the anterior teeth, unilateral biting of a cotton roll with the posterior teeth, bilateral biting of cotton rolls with the posterior teeth, and jaw opening while seated. Normalized amplitude, activity indices, and asymmetry indices were compared between the muscles and the jaw tasks. Results: During symmetrical jaw functions (e.g., tooth clenching, biting with the anterior teeth, bilateral biting with the posterior teeth, jaw opening), the sternocleidomastoid and posterior cervical muscles showed elevated EMG amplitudes compared with the resting condition. The co-activation pattern of the sternocleidomastoid muscle was more pronounced than those of the posterior cervical muscles during these tasks. During asymmetrical jaw functions (e.g., unilateral biting with the posterior teeth), the ipsilateral sternocleidomastoid and masseter muscles showed higher contraction activity than did the contralateral muscles, but the contralateral posterior cervical muscles were more active than the ipsilateral muscles. Conclusions: The sternocleidomastoid and posterior cervical muscles were shown to be co-activated and coordinated anteroposteriorly or bilaterally according to symmetrical or asymmetrical jaw function. These results suggest an integrated neural control mechanism for the jaw and neck muscles, and provide further evidence supporting the intimate functional coupling between the trigeminal and cervical neuromuscular systems.

• 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.

• The Korean Journal of Physiology
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• v.26 no.2
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• pp.151-157
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• 1992

In urethane anesthetized cats, each vestibular semicircular canal nerve was electrically stimulated, and reflex responses of the cervical extensor and flexor (the splenius capitis and sternomastoid muscles) were recorded by means of electromyography. Stimulation of a unilateral (anterior, horizontal or posterior) canal nerve elicited excitation of the contralateral cervical muscles and inhibition of the ipsilateral ones; during the canal nerve stimulation, the two muscles in one side of the neck revealed synergistic responses. Based on these experimental results, we formulated a diagram showing the functional connections between the vestibular semicircular canals and the cervical muscles in the vestibulocollic reflex.

• PNF and Movement
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• v.21 no.3
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• pp.299-307
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• 2023

Purpose: The purpose of this study was to compare the effects of new exercises (combined cervical and thoracic extension exercises) with those of conventional cervical extensor strengthening exercises (sitting cervical extension exercises) and thoracic extensor strengthening exercises (prone thoracic extension exercises). Method: Fifteen healthy subjects performed sitting cervical extension exercises, prone thoracic extension exercises, and combined cervical and thoracic extension exercises. During each exercise, electromyography was used to measure muscle activity in the erector spinae with C4 and T4 levels. The measured data were analyzed using one-way repeated analysis of variance. Results: With different exercises, there were significant differences in activity in the erector spinae muscle (p < 0.05). The activity in the erector spinae muscle increased significantly during the combined cervical and thoracic extension exercises compared to the sitting cervical extension (p < 0.05) and prone thoracic extension exercises (p < 0.05). The sitting cervical extension exercises significantly increased activity in the cervical erector spinae muscle compared to the prone thoracic extension exercises (p < 0.05). Activity in the thoracic erector spinae muscles was significantly increased during the prone thoracic extension exercises compared to during the sitting cervical extension exercises (p < 0.05). Conclusion: These findings suggest that the newer exercises effectively increase activity in the cervical and thoracic extensor muscles.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.139-143
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• 2010

Whiplash injuries often occur in motor vehicle collision accidents. This injury frequently occurs in the cervical region. However, the reason for this has not yet been clarified. In this study, a multi-body neck model with muscles was designed. Some muscles in the model were preloaded; these were previously determined using the concept of the follower load. Cervical spinal vertebrae, discs, and muscles were designed in accordance with the human cervical spine. The purpose of this study was to investigate the effect of preloads on muscles. The results imply that the whiplash model with preloaded muscles simulates practical situations more closely than models without preloads.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.1
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• pp.41-48
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• 2022

PURPOSE: This study examined the relationship between the cervical lordosis angle (CLA) and the craniovertebral angle (CVA) and between CVA and a cross-sectional area (CSA) of the cervical muscles. METHODS: In 17 healthy college students, the CLA was measured using a posterior tangent technique. The CVA was analyzed using photographic images, and the CSA of the cervical muscles, including longus colli, longus capitis, and sternocleidomastoid, was evaluated using computerized tomography. The Pearson's correlation coefficient was used to determine the relationship between these variables and a neck disability index. RESULTS: The CVA correlated with the CLA and with a CSA of longus colli (r = .487, p = .047 and r = .592, p = .012, respectively). The CLA correlated with a CSA of longus colli (r = .578, p = .015). CONCLUSION: This study clarified the relationship between the postural, structural, and muscular changes in the cervical regions. A significant correlation was observed between the CVA and a CSA of the longus colli with the CLA and between the CVA and the CSA of the longus colli. Prescription strengthening exercises for the deep neck flexors for individuals with a forward head posture and reduced cervical lordosis are useful.

• 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.

• Annals of Clinical Neurophysiology
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• v.8 no.1
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• pp.88-90
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• 2006

Pneumothorax after needle electromyography is a rare complication, which usually associated with examination of diaphragmatic and intercostal muscles. However, by the literatures, it can also occur with supraspinatus, serratus anterior and paraspinal muscles. We experienced a case of pneumothorax after cervical paraspinal muscle needle electromyography. From the anatomical vulnerability of pneumothorax during needle insertion, we emphasized the importance of avoiding this complication.