• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.45-59
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• 1989

This study was undertaken to analyze the displacement and stress distribution in the mandible according to the pulling directions during mandibular first molar cervical traction after mandibular second molar extraction. The 3-dimensional finite element method(FEM) was used for a mathematical model composed of 594 elements and 1019 nodes. An orthodontic force, 450 gm, was applied to the each mandibular first molar in parallel, and below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$ and meet the midsagittal plane by $40^{\circ}$ toward posterior direction. The results were as follows: 1. Mandibular teeth were displaced in more downward, posterior and lateral direction. Especially high stress was noted in case of parallel pull than in case of below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$. 2. Mandibular first molar was moved bodily. 3. Generally, alveolar bone, mandibular body, ascending ramus and mandibular angle portion were displaced in downward, posterior and lateral direction. But coronoid process was displaced in downward, forward and lateral direction, and anterior and inner middle portion of condyle head and neck were displaced in downward, forward and medial direction, and posterior and outer middle portion of condyle head and neck were displaced in upward, forward and medial direction. 4. Maximum stress was observed at the condyle head and neck portion. With steeper direction of force, condyle head and neck showed more stress than parallel relation to the occlusal plane.

• The Journal of Korean Physical Therapy
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• v.32 no.5
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• pp.319-324
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• 2020

Purpose: This study was to investigate the effect of dorsal neck muscle fatigue on the cervical range of motion (CROM) and proprioception in adults with the forward head posture (FHP). Methods: Thirty pain-free subjects were enrolled in this study. All subjects were measured the forward head angle by taking the capture of the sagittal plane of their upper body to determine the FHP. Subjects were distributed into two groups: the FHP group (n=14) and Control group (n=16). All subjects were measured the CROM and the Head repositioning accuracy (HRA) for joint proprioception before and after inducing muscle fatigue of the dorsal neck. The CROM and HRA were measured in neck flexion, extension, right-left lateral flexion, and right-left rotation. Sorenson's test was used to induce muscle fatigue of the dorsal neck. Results: Total CROMs were significantly decreased after dorsal neck muscle fatigue in both groups (p<0.05). Total HRAs were significantly increased after dorsal neck muscle fatigue in the FHP group (p<0.05), but there were no significant differences in the control group (p>0.05). Total CROM changes were not significant differences between groups (p>0.05), but total HRA changes were significant differences between groups (p<0.05) except for right and left lateral flexion (p>0.05). Conclusion: Immediate CROM and proprioception reduction after the dorsal neck muscle fatigue were observed in adults with the FHP. Therefore, FHP can significantly affect the CROM and positioning consistency of cervical proprioception.

• Physical Therapy Korea
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• v.27 no.4
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• pp.264-271
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• 2020

Background: Because a forward-leaning posture can cause increased back muscle activity and pain. Therefore, an innovative method to reduce back muscle activity and pain is required. Objects: This study aimed to investigate the effects of a head support on muscle activity and pain in a forward-leaning posture. Methods: A total of 14 male and 16 female students (average age, 21.65 ± 2.37 years; height, 166.15 ± 7.90 cm; and weight, 60.65 ± 9.00 kg) were recruited for the experiment. Two of them were excluded due to musculoskeletal disorders. The muscle activity and pain in the forward-leaning posture were assessed while participants washed dishes for 7 minutes with and without a head support. The condition of using a head support was randomly performed with a 5-minutes break. To confirm a lumbar flexion angle of 30° during the experiment, myoVIDEO was used, and surface electromyography was used to measure muscle activity. Pain was assessed using a 10-point visual analog scale (VAS). The Wilcoxon signed-rank test was used to analyze the data, with p < 0.05 indicating statistical significance. Results: The cervical, thoracic, and lumbar erector spinae muscle activities significantly decreased with the use of the head support, but there was no significant change in the gluteus maximus. There was a significant decrease in the VAS score for the lumbar erector spinae (p < 0.05), but there was no significant change in the VAS score for the cervical region. Conclusion: The use of a head support in a forward-leaning posture reduced cervical, thoracic, and lumbar erector muscle activity and pain. Therefore, it could be recommended during working in a forward-leaning posture, such as during dishwashing, cooking, and working as a factory employee.

• The Korean Journal of Pain
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• v.33 no.1
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• pp.48-53
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• 2020

Background: The aim of this study was to clarify the topographical relationship between the accessory nerve (AN) and transverse cervical artery (TCA) to provide safe and convenient injection points for AN blockade. Methods: This study included 21 and 30 shoulders of 14 embalmed Korean adult cadavers and 15 patients, respectively, for dissection and ultrasound (US) examination. Results: The courses of the TCA and AN in the scapular region were classified into four types based on their positional relationships. Type A indicated the nerve that was medial to the artery and ran parallel without changing its location (38%). In type B (38%), the nerve was lateral to the artery and ran parallel without changing its location. In type C (19%), the nerve or artery traversed each other only once during the whole course. In type D (5%), the nerve or artery traversed each other more than twice forming a twist. At the levels of lines I-IV, the nerve was relatively close to the artery (approximately 10 mm). TCAs were observed in all specimens around the superior angle of the scapula at the level of line II, whereas they were not found below line VI. In US images of the patients, the TCA was commonly observed at the level of line II (93.3%) where all ANs and TCAs were observed in cadaveric dissection. Conclusions: The results expand the current knowledge of the relation between the AN and TCA, and provide helpful information for selective diagnostic nerve blocks in the scapular region.

• Physical Therapy Korea
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• v.27 no.1
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• pp.45-52
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• 2020

Background: A backpack is available equipment for moving some objects. Most studies have found that the appropriate weight limit of backpack for students is between 10% to 15% of their body weight (BW). However, Some students should carry a backpack heavier than 15% of BW. Therefore, It is associated with abnormal shoulder and neck posture on students. Objects: This study tested the effects that various amounts of weight carried by university students in their backpacks had on their cervical posture and electromyography of neck muscle. Methods: The subjects consisted of 12 students (6 male, 6 female) in university. There were three loading conditions tested: no backpack, a backpack that weighed 10% and 15% of the student's BW. The dependent variables were the craniovertebral angle (tragus to C7) and the neck muscle activities (sternocleidomastoid, upper trapezius). All 12 subjects were asked to walk while wearing a backpack for 5 minutes and were then instructed to rest for 2 minutes. Results: When assessing the craniovertebral angle, the results of this study were significantly decreased in the order of 0%, 10%, and 15%. And then, there were significantly increased electromyography of neck muscles that comparison of the weight of 10% and 15% on 0%. It was found that as the weight of the backpack increased, the craniovertebral angle decreased (p < 0.05) and the muscle activities increased (upper trapezius p = 0.012, sternocleidomastoid p = 0.013). Conclusion: Our study recommended that some students shouldn't carry on over the 15% backpack of own weight, and also they should distribute backpack load to equal on body for optimal posture.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.543-551
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• 2018

This study investigated the effects of corrective exercise and TECAR on cervical alignment, pain threshold, and pain in forward head posture patients. The subject includes 30 forward head posture patients. In the intervention methods, the experimental group combined corrective exercise and TECAR treatment. Only the corrective exercise was applied to the control group. Assessments were made on cervico vertebra angle (CV angle), pain pressure threshold (PPT) and neck disability index (NDI) visual analog scale (VAS). The intervention was conducted six times a week for two weeks. Both groups showed significant differences in CV angle, PPT, NDI, and VAS. Also, PPT, NDI, and VAS excluding CV angle were significantly improved in the study group compared to the control group. These results suggest that the intervention method that combines corrective exercise and TECAR treatment has a more positive effect on pain and ADL ability of forward head posture patient.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.2
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• pp.80-85
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• 2020

Recently the incidence of musculoskeletal disorders in students and office workers is increasing, and the necessity of maintaining correct posture and corrective training is required, but related research is insufficient. In the previous study, a membrane sensor or a pressure sensor was placed on the seat cushion to see the deviation of the body weight, or a sensor that restrained the user was attached to measure the position change. In this study, a sensor device for detecting a position change in consideration of wearing comfort was developed, and the measured angle was verified through an analysis app. A sensor device consisting of an IMU sensor is attached to the cervical spine and vertebra spine to measure the position transformation in the sitting position. The change value of the position measured by the two sensors was converted into an angle, and the angle value is displayed in real time through the analysis app. In this study, the possibility of measuring the real-time change value according to the change in position, the convenience of wearing, and the tendency of angle measurement were proved. Future research should proceed with more precise angle calculation and correction of motion noise.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.454-463
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• 2022

Objective: The purpose of this study was to compare concurrent validity and test-retest reliability based on Craniovertebral angle of 'Angles video goniometer', a smart phone application for convenient range of motion measurement, and 'Image J', an analysis software with high reliability and validity. This was conducted to find out whether 'Angle video goniometer' can be used clinically. Design: Cross-sectional study Methods: Fifty subjects were imaged laterally, and the angle of the head and spine was measured using Image J and the Angles video goniometer, respectively, in a resting posture and a chin in posture. The level of concurrent validity between the two measurement methods and the level of inter-rater reliability and intra-rater reliability were analyzed. Results: For forty participants, the concurrent validity between Image J and Angles video goniometer showed very high validity with ICC of 0.997(0.995~0.999) and 0.994(0.994~0.998), CVME% 0.71~0.72%, SEM% 0.31~0.34, MDC% 0.86~0.94. The test-retest intra-rater reliability showed very high reliability ICC 0.994(0.991~0.996), CVME% 0.71%, SEM% 0.31~0.43, MDC% 0.86~1.19%. The test-retest inter-rater showed very high reliability ICC 0.995(0.992~0.997), CVME% 0.71%, SEM% 0.43~0.59%, MDC% 1.20~1.62% Conclusions: Angles video goniometer', a smartphone application, is a device with very high reliability and validity for craniovertebral angle measurement in healthy adults, and it is a device that can be easily used in clinical practice.

• Journal of Korean Foot and Ankle Society
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• v.28 no.2
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• pp.60-67
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• 2024

Purpose: Sinus tarsi syndrome (STS) is caused by various pathologies. However, the exact etiology of STS remains controversial. This study evaluated the imaging and arthroscopic findings of patients who underwent surgical treatment after conservative treatment for STS failed. Materials and Methods: Between December 2014 and August 2018, 20 patients (21 cases) who underwent surgical treatment for STS were included in the study. The clinical results were analyzed using the visual analog scale (VAS) and the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot functional scale. The radiographic results were analyzed using Meary's angle, calcaneal pitch angle, and hindfoot alignment angle. The pathologic conditions of sinus tarsi were confirmed by magnetic resonance imaging (MRI) and subtalar arthroscopy. Synovitis, bone edema, and accessory anterolateral talar facet (AALTF) were evaluated on MRI. Synovial thickening, cartilage damage, interosseous talocalcaneal ligament (ITCL) and cervical ligament rupture, soft tissue impingement, AALTF, and accessory talar facet impingement (ATFI) were evaluated by subtalar arthroscopy. Results: The mean duration of symptoms was 28.7 months (4~120). All patients showed significant improvement in the VAS and AOFAS ankle-hindfoot scale. Significant improvements in hindfoot alignment angle and Meary's angle postoperatively were noted in patients who underwent medial displacement calcaneal osteotomy. MRI confirmed synovitis in all patients, AALTF in 19 cases (90.5%), and ATFI with bone edema in seven cases (33.3%). In subtalar arthroscopy, pathologic conditions were observed in the following order: synovitis in 21 cases (100%), AALTF in 20 cases (95.2%), ITCL partial rupture in nine cases (42.9%), and soft tissue impingement in seven cases (33.3%). All cases had two or more pathological conditions, and 15 (71.4%) had three or more. Conclusion: In cases of STS that do not respond to conservative treatment, a comprehensive examination of the lesions of the tarsal sinus and lesions around the subtalar joint is essential.

• Physical Therapy Korea
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• v.23 no.2
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• pp.57-66
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• 2016

Background: For the treatment of forward head posture (FHP) and forward shoulder posture, methods for strengthening scapular retractors and deep cervical flexors and stretching pectoralis and upper cervical extensors are generally used. No study has yet assessed whether suboccipital release (SR) followed by cranio-cervical flexion exercise (CCFE) (SR-CCFE) will result in a positive change in the shoulders and neck, showing a "downstream" effect. Objects: The purpose of this study was to investigate the immediate effects of SR-CCFE on craniovertebral angle (CVA), shoulder abduction range of motion (ROM), shoulder pain, and muscle activities of upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) and LT/UT and SA/UT muscle activity ratios during maximal shoulder abduction in subjects with FHP. Methods: In total, 19 subjects (7 males, 12 females) with FHP were recruited. The subject performed the fifth phase of CCFE immediately after receiving SR. CVA, shoulder abduction ROM, shoulder pain, muscle activities of UT, LT, and SA, and LT/UT and SA/UT muscle activity ratios during maximal shoulder abduction were measured immediately after SR-CCFE. A paired t-test and Wilcoxon signed-rank test were used to determine the significance of differences in scores between pre- and post-intervention in the same group. Results: The CVA (p<.001) and shoulder abduction ROM (p<.001) were increased significantly post-versus pre-intervention. Shoulder pain was decreased significantly (p<.001), and LT (p<.05) and SA (p<.05) muscle activities were increased significantly post- versus pre-intervention. The LT/UT muscle activity ratio was increased significantly post- versus pre-intervention (p<.05). However, there was no significant change in UT muscle activity and SA/UT muscle activity ratio between pre- and post-intervention (p>.05). Conclusion: SR-CCFE was an effective intervention to improve FHP and induce downstream effect from the neck to the trunk and shoulders in subjects with FHP.