• The Journal of Korean Physical Therapy
• /
• v.32 no.6
• /
• pp.325-328
• /
• 2020

Purpose: This study examined the effects of the directions of neck rotation position on the muscle activity and strength of the elbow flexor and extensor muscle. Methods: Forty-one healthy adults participated in this study. The subjects were asked to their elbow 90° flexion in three different neck rotations (neutral, ipsilateral, and contralateral) in the sitting position. The muscle activities of the biceps and triceps brachii muscle were measured using surface electromyography. And the muscle strength of the elbow flexor was measured using dynamometer. One way repeated measures ANOVA was used to compare the muscle activity and strength of the elbow flexor and extensor depending on the different neck turning directions. Results: There were significant differences between contralateral neck rotation and ipsilateral neck rotation, contralateral neck rotation and neutral position. But, there was no significant difference in the triceps brachii muscle activity in comparison with the neck rotation. There were significant differences between contralateral neck rotation and ipsilateral neck rotation, contralateral neck rotation and neutral position. Conclusion: To summarize this study, the elbow flexor and extensor muscle activity and strength was highest in the contralateral neck rotation position. In other words, it was possible to confirm the effect of Asymmetrical Tonic Neck Reflex in healthy adults whose primitive reflexes were inhibition, and head and neck positions should be considered during clinical evaluation and treatment.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.27 no.2
• /
• pp.1-8
• /
• 2021

Background: Chronic neck pain (CNP) is associated with weakness in the deep neck flexor muscles, a shortening of the neck extensors, and a reduction in endurance. In addition, muscle imbalance can lead to neck pain and musculoskeletal dysfunction. This study compared neck extensor muscle fatigue, muscle strength, and muscle endurance time between patients with CNP and healthy adults during isometric neck extension. Methods: Thirty participants (15 patients with CNP and 15 healthy adults) were recruited in this research. The outcome measures included splenius capitis (SC) muscle fatigue, isometric neck extensor strength, and muscle endurance. The independent T-test was used to compare the continuous dependent variables between the CNP group and the healthy group. Results: The independent T-test indicated that muscle fatigue in the left SC differed significantly between the CNP group and the healthy group. A significant difference was also noted in the isometric neck extensor and neck extensor strength between the groups. Conclusion: Our results provided promising clinical evidence that patients with CLP have reduced neck extensor strength and endurance and increased SC muscle fatigue, which results in neck pain.

• Journal of the Korean Society of Physical Medicine
• /
• v.14 no.2
• /
• pp.137-144
• /
• 2019

PURPOSE: The continued use of smartphones has resulted in an abnormal body posture and neck alignment changes. Maintaining this posture for a long time weakens the flexor muscles in the neck and shortens the extensor muscles in the neck. This study examined the correlation between the suboccipital muscle tension and deep neck flexor muscle physical endurance according to the craniovertebral angles. METHODS: The craniovertebral angle, tension of the suboccipital muscle and endurance of the deep neck flexor muscle were measured in 58 healthy 20-year-old male and female college students. The tension of suboccipital muscle and endurance of the deep neck flexor muscle were then divided according to the body mass index (BMI). Their correlation with the craniovertebral angle was then examined. Each parameter was measured three times to determine the interrater reliability. RESULTS: The craniovertebral angle and suboccipital muscle tension showed differed significantly. On the other hand, the craniovertebral angle and deep neck flexor muscle physical endurance showed no significant differences. CONCLUSION: The results show that the craniovertebral angle and deep neck flexor muscle physical endurance were not correlated, but a smaller craniovertebral angle resulted in a higher suboccipital muscle tension.

• Journal of International Academy of Physical Therapy Research
• /
• v.9 no.4
• /
• pp.1619-1625
• /
• 2018

To examine the changes in pain, the severity of the neck disorder, craniovertebral angle, and muscle activity in young adults with forward head posture. 37 "N" University students in their 20s with forward head posture, including both male and female participants. Measurement of pain, NDI (neck disorder index) craniovertebral angle, and muscle activity were taken before and after the 6 week intervention period. The pain was measured using the visual analog scale. The severity of the neck disorder was measured using the NDI The craniovertebral angle was measured by taking a photo. The muscle activity was measured using surface electromyography. Neck posture correction exercises paired with proprioceptive training is the most effective intervention for reducing pain. Both neck posture correction exercises paired with Kinesio taping or proprioceptive training are effective interventions for addressing neck disability, craniocervical angle, and muscle activity. Neck posture correction exercises paired with Kinesio taping or proprioceptive training are more effective at addressing pain, neck disorder, craniocervical angle, and muscle activity than performing the neck posture correction exercises alone.

• Journal of the Ergonomics Society of Korea
• /
• v.30 no.2
• /
• pp.297-302
• /
• 2011

Many WMSDs(work-related-musculoskeletal disorders) have been reported in diverse industries and have also attracted much attention in recent years. Neck-related MSD is generally known as one of common WMSDs, especially it happens to workers who are working at the automobile assembly plants and/or shipyards. The awkward posture is considered as a main cause of neck-related MSDs. A neck supporter was developed to prevent neck-related MSDs, and 10 males were recruited to evaluate the newly developed neck supporter by measuring subjective discomfort ratings of whole body, shoulder, neck and neck-muscle activities. Muscle activities from four neck muscle groups(left/right sternocleidomastoid and upper/middle trapezius) were measured while simulating an automobile assembly task. Results showed that the neck supporter help to significantly improve subjective discomfort for whole-body, shoulder as well as neck body parts. The analyses of muscular activities also showed that the activities of left/right sternocleidomastoid muscles were statistically decreased with the neck supporter in this study. The muscle activities of upper/middle trapezius in case of wearing the neck supporter were not significantly different with the muscle activities in case of no-wearing the neck supporter. Overall findings verified that the neck supporter might help to prevent neck-related MSDs based on the current study.

• Journal of The Korean Society of Integrative Medicine
• /
• v.12 no.1
• /
• pp.125-138
• /
• 2024

Purpose: The aim of this study was to apply suboccipital muscle inhibition combined with neck muscle stabilization exercise to 20~30s IT industry employees who suffer from chronic non-specific neck pain. Methods: This study was designed as single-blind and randomized controlled trial. The study participants were 20~30s IT industry employees with chonic non-specific neck pain (VAS 3/10) who were divided into an experimental group (n= 20) subjected to suboccipital muscle inhibition with neck muscle stabilization exercise, and control group (n= 20); suboccipital muscle inhibition only. The intervention was applied three times per week for eight weeks. The neck pain·pressure pain threshold·range of motion, and disability index were measured at the 1st, 8th, and 10th week at follow up, then analyzed with an analysis of variance(ANOVA) using the SPSS program. Results: The total number of study participants was 37 (experimental group 19, mean age 34.6±5.3, control group 18, mean age 35.7±4.9). The comparison and analysis of change in VAS, the pressure pain threshold, and the range of motion except the extension (p>.05) revealed a statistically significant decrease between groups over eight weeks and follow up measurement (p<.01). Regarding the within the group differences, the right side of the neck pressure pain threshold showed a statistically significant decrease over eight weeks in the control group (p<.01). The right and left lateral flexion, and the right and left rotation were statistically significant for the experimental group over eight weeks and follow up measurement, but only the left lateral flexion (p<.05) for the control group over eight weeks. The neck disability index showed a slight decrease but this was not satistically significant for the between-grop or the within-group differences (p>.05). Conclusion: The intervention of suboccipital muscle inhibition and a neck muscle stabilization exercise are more beneficial for neck pain and the range of motion than the application of suboccipital muscle inhibition alone.

• The Journal of Korean Physical Therapy
• /
• v.35 no.5
• /
• pp.151-155
• /
• 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.

• Physical Therapy Korea
• /
• v.23 no.2
• /
• pp.20-34
• /
• 2016

Background: It is necessary to find and develop the effective way of intervention for patients with neck pain, since the neck pain is becoming increasingly common throughout the world. To identify the altered motor control in patient with neck pain would be informative to find and develop the effective way of intervention. Objects: The aim of this study was to review literature regarding the altered motor control in patients with neck pain, measured by using surface electromyography (sEMG), ultrasonography, and functional magnetic resonance imaging (fMRI), and to suggest prospective research work on neck pain. Methods: Case-control (neck pain/healthy) studies published between 2004 and 2015 that investigated neck muscle activation, thickness, cross-sectional area, and fat infiltrate were searched in Scopus, PubMed, and ScienceDirect. Twenty-eight articles were included in this study. Results: sEMG, ultrasonography, and fMRI were used complementarily to investigate the altered superficial and deep neck muscle activation, thickness, cross-sectional area, and fat infiltrate in patients with neck pain. They showed the following altered motor control when compared retrospectively with healthy subjects or during specific functional tasks: (1) increased superficial muscle activation, (2) lesser deep muscle thickness, (3) smaller cross-sectional area of the deep muscle, and (4) greater fat infiltrate in deep muscles. In particular, among the women, the office workers showed higher muscle activation of superficial neck muscles during functional tasks, although they did not have neck pain, than those who were not office workers. Conclusion: Studies revealed that patients with neck pain showed an altered motor control when compared with healthy subjects by using various assessment modalities. Understanding this phenomenon would help researchers design an effective intervention for alleviating neck pain or to evaluate the effectiveness of the intervention. In addition, we recommend that female office workers take measures to care for their necks before developing neck pain.

• Journal of Korean Physical Therapy Science
• /
• v.31 no.1
• /
• pp.88-97
• /
• 2024

Background: This study was to investigate effects of Correlation Analysis between Cervical-Vertebra Angle and Neck Range of Motion, Muscle Strength, Sternocleidomastoid Thickness of Patients with Forward Head Posture Design: Correlation Analysis. Methods: The subjects of this study were a total of 54 people in the forward head position and their ages were between 30 and 50 years old. The subjects cranio-vertebral angles, neck extension, neck flexion, neck rotation angles, neck flexor strength, neck extensor strength, sternocleidomastoid thickness were evaluated through measuring instruments. The thickness of the sternocleidomastoid muscle was measured using an imaging ultrasound diagnostic device (ultra sound, Versana Premier, GE Medical systems, China). CVA was measured by measuring the side photo of the subject was taken with a camera and evaluated.. neck joint range of motion was measured through digital inclinometer for extension, flexion, and neck rotation. neck muscle strength was measured by measuring the using a digital sthenometer. Data analysis in this study was statistically processed using SPSS version 26.0 (IBM SPSS Inc., USA). Correlation analysis was used and the statistical significance level was set at 0.05. Results: The results neck extension(r= 0.70^**), neck flexion(r= 0.67^**), neck rotation(r= 0.56^**), neck extensor muscle strengt(r= 0.85^**), neck flexor muscle strength(r= 0.66^**), sternocleidomastoid thicknes(r= -0.81^**) It indicates that there is a correlation. Conclusion:These results improve the Cervical-vertebra angle of patients with forward head posture should include a program to improve the thickness of the SCM. In the future, study can be used as an evidentiary material for treatment interventions to improve the Cervical-vertebra angle of patients with forward head posture.

• The Journal of Korean Physical Therapy
• /
• v.30 no.6
• /
• pp.218-223
• /
• 2018

Purpose: The purpose of this study was to evaluate the impact of active vibration exercise on the neck pain, disability index, and muscle activity of patients with forward head posture. Methods: A total of 24 patients were randomly assigned to an experimental group or a control group (n=12 each). The experimental group performed active vibration exercise using a flexi-bar for 20 minutes a day, five times a week for four weeks. The study measured patient neck pain using a visual analog scale, neck pain related disability using the neck disability index, and muscle activity using electromyography. Results: The intragroup comparison showed significant differences in the visual analog scale score, neck disability index score and upper trapezius, lower trapezius and serratus anterior muscle activity values among patients in the experimental group. The intergroup comparison showed that differences in the visual analog scale score, neck disability index score and upper trapezius, lower trapezius and serratus anterior muscle activity values in the control group. Conclusion: This study showed that active vibration exercise was effective in improving the neck pain, disability index, and muscle activity of patients with forward head posture.