• Journal of Oral Medicine and Pain
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• v.30 no.3
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• pp.337-344
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• 2005

A tactile sensor employs a piezoelectric element to detect contact frequency shifts and thereby measure the stiffness or softness of material such as tissue, which allows the sensor to be used in many fields of research for urology, cardiology, gynecology, sports medicine and caner detection and especially for cosmetics and skin care. In this study, reliability of the tactile sensor system was investigated with its manual application to the muscles susceptible to temporomandibular disorders. Stiffness and elasticity of anterior temporalis, masseter and trapezius muscles were calibrated bilaterally from 5 healthy men with an average of 24.5$\pm$0.94 years. The tactile sensor used in this study had a computer-controlled and motor-driven sensor unit which automatically pressed down on the skin surface over the muscles being measured and retracted, thereby providing the hysteresis curve. The slope of the tangent of the hysteresis curve (${\Delta}f/{\Delta}x$) is defined as stiffness of the muscle being measured and the distance between the two parts of the curve as its elasticity. To determine inter-examiner reliability, all the measurements were performed by the two examiners A and B, respectively and the same examination were repeated with an interval of 2 days for intra-examiner reliability. The results from this study demonstrated high reliability in measuring stiffness and elasticity of anterior temporalis, masseter and upper trapezius muscles using a tactile sensor system. It is suggested that the tactile sensor system can be a highly reproducible and effective instrument for quantitative evaluation of the muscle in head and neck region.

• Korean Security Journal
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• no.25
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• pp.89-107
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• 2010

The purpose of this study was to evaluate the effects of using cervical spinal stabilization exercise for the improvement of pain intensity, cervical range of motion, neck disability index, reposition sense, muscle tenderness with chronic neck pain in private security. For 21 patients diagnosed with chronic cervical pain and divided into cervical spinal stabilization exercise group and postural correction exercise group. Each exercise was conducted for 8 weeks. Pain and neck disability index were measured before and after exercise using the visual analogue scale(VAS) and the neck disability index(NDI). Range of motion were measured electronic goniometer, muscle tenderness of upper trapezius ad sternocleidomatoid were measured algometer, reposition sense were measured reposition panel before and after exercise. After 8 weeks of exercise, the cervical stabilization exercise group pain and neck disability were significantly decreased(p<0.05). Also there was significant difference in both group(p<0.05). In addition, range of motion, muscle tenderness reduce rate, reposition sense were significantly increase as compared to the pre-post exercise in cervical stabilization exercise group(p<0.05). But there was no significantly difference in postural correction group before and after exercise(p>0.05). And there was significantly increase more cervical stabilization exercise group than postural correction exercise group in range of motion, muscle tenderness reduce, reposition sense. In summary, cervical spinal stabilization exercise is more effective in improving cervical range of motion, muscle pain, reposition sense in private security on chronic cervical pain patients, in reducing patients' pain and disability. It is an effective treatment to aid rehabilitation in these cases.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.180-190
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• 2016

This prospective pilot clinical trial mainly focuses on developing dual chamber-based assistive cups which are suitable for stroke patients who have struggled with using there affected arms. It is unable to provide motor and sensory enhancement during drinking activities and to examine the feasibility of the devices for acute phase, even for chronic stroke survivors. The stroke patients(n=16; male=8, female=8), in this trial, were provided informed consent to the investigation. All the individuals participated in 1 weeks of training for using cups, randomized over dedicated dual chamber based assistive cups(DC) or placebo-cups(PC) training. All the participants were assessed within 1 week before and after the intervention period. 3-dimensional motion analysis, sEMG(surface electromyography) and 3-dimensional trunk movement were assessed. The result presents DC data group compared with PC showed, they needed lesser ROM(range of motion) at the phase of drinking in shoulder movements and lesser muscle activities on upper trapezius, deltoid middle fiber and triceps brachii muscles, lesser tilting movement on front and back side in drinking phase, the differences were statistically significant(p<.05). Dual chamber-based assistive cup could be one of efficient way to complete ADLs(activities of daily living), especially drinking tasks, and these evidence data may contribute to determine certain rehabilitation policies related to assistive devise usage.

• Journal of the Ergonomics Society of Korea
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• v.34 no.4
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• pp.313-326
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• 2015

Objective: The objective of this research is to quantitatively analyze muscle activities of arm and shoulder, according to direction in various types of one-handed manual material handling, based on surface electromyography. Background: Workers in industrial sites frequently carry out one-handed manual material handling using arm and shoulder muscles. Therefore, chronic load and accumulated fatigue occur to arm and shoulder muscles, which becomes a main cause of upper arm and shoulder musculoskeletal disorders. The shoulder muscles have widely range of motion, and complex interactions take place among various muscles including rotator cuff muscles. In this regard, research on interactions among should muscles, according to such various dynamic motions, is required. Method: Ten male subjects in their 20s participated in this research. This research considered upward, downward, leftward, rightward, forward and backward directions and fourteen muscles around arm and shoulder (biceps brachii and trapezius, etc.) as independent variables. The mean muscle activity was set as the dependent variable. This research extracted $4^{th}{\sim}7^{th}$ repetition signals according to ten times of repetitive muscle contraction, and analyzed the muscle activity concerned using the envelope detection technique. Results: The mean muscle activity of upward direction was analyzed highly statistically significant. The reason is that the effect of gravity works to arm and shoulder muscles. Also, it is conjectured that deformation of coracoacromial ligament was caused, and its contact pressure increased, due mainly to the shoulder flexion, and therefore load was analyzed high. Muscle activity was analyzed significantly low, according to concentric ballistic motion used in the concentric contraction phase by storing elastic energy in the eccentric contraction phase with a motion to bring the weight to the front of subject's body as to downward, leftward and backward directions. Because, elbow joint's flexion-extension motions mainly occurred, biceps brachii was analyzed high muscle activity as the prime mover. Conclusion: The information on the quantitative load of muscles can be applied to ergonomic work design for one-handed manual material handling to minimize muscle load. Application: This research has effectively identified muscle activity according to dynamic contraction by applying an envelope detection technique. The results can be used for ergonomic work design to minimize muscle load during the one-handed manual material handling, according to each direction. The research results are expected to be used for musculoskeletal disorder prevention and physiotherapy in the rehabilitation medical field, based on the muscle load of arm and shoulder in various directions.

• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.779-790
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• 1997

The Association between myofascial pain syndrome and some tests was assessed in a cross-sectional study of 904 female telephone operators using video display terminals(VDTs). 105 cases were diagnosed as Myofascial pain syndrome with symptom questionnaire, laboratory examination and physician's physical examination and 550 controls were defined to show only musculoskeletal symptoms using NIOSH symptom criteria. Data on demographics, musculoskeletal symptom and visual analogue scale(VAS) were obtained by questionnaire. Anthropometric measurements, pressure pain threshold, Grip & Pinch strength and laboratory test were conducted. No significant difference between case and control at comparing of demographics, occupational history and body measurements were observed. But, Grip strength, pressure pain threshold and VAS showed the statistical difference between case and controt. Age, pressure pain threshold of Rt. Upper trapezius and VAS were associated with myofascial pain syndrome in multivariate logistic regression analysis. This results suggest that, to diagnose of myofascial pain syndrome, the consideration of the objective aspects among patients' subjective symptom complaints through the VAS and pressure pain threshold is required.

• Archives of Reconstructive Microsurgery
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• v.18 no.2
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• pp.55-61
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• 2009

Purpose: To analyze the clinical and radiologic results of the shoulder arthrodesis in brachial plexus injury patients with flail upper extremity. Material and Method: From Aug 1978 to April 2008, 29 shoulders in 29 patients with brachial plexus injury with shoulder fusion, we evaluated 20 shoulders in 20 patients, more than 1 year follow up. The average follow-up period was 6.45years (range: 1year~24years). There were 13 men and 7 women, and the mean age at the time of trauma was 32.0years(2~65 years). The type of injury was a motorcycle accident in 11 patients, in car accident in 5, pedestrian accident in 3, and fall from a height in 1. The lesion of injury was root and trunk in 1 patient, trunk and cord in 1, trunk in 18. Surgery was performed on the whole arm type paralysis in 12 patients, lower arm type paralysis in 8 patients. The preoperative visual analog scale score was 8.7(7~10). When the trapezius and serratus anterior muscle were in function, operation was performed. 18 patients were processed to the additional operation. Gracilis free flap in 6 patients, neurotization in 3, Steindler flexor plasty in 6, and tendon transfer in 3 were performed. Fixation was conducted with cancellous screws in 13 patients, Knoles pins in 5, and cancellous screws and Knoles pins in 2. The position of the arthrodesis at operation was $28.5^{\circ}$($20~45^{\circ}$) in abduction, $30.3^{\circ}$($20~45^{\circ}$) in flexion, and $30.8^{\circ}$($20~40^{\circ}$) in internal rotation. Result: The follow up visual analog scale score was 3.4(0~7). Postoperatively, shoulder spica cast was applied for 15.3weeks(8-20weeks). The median time to bony union was 17.7weeks(9~28weeks). Average range of motion was $32.0^{\circ}$($15~40^{\circ}$) of abduction, $24.0^{\circ}$($10~40^{\circ}$) of flexion, and $18.5^{\circ}$($10~30^{\circ}$)of internal rotation. Conclusion: The shoulder fusion in brachial plexus injury patients is one of the good methods to relieve pain, improve the function and stabilize the flail shoulder joint.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.209-216
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• 2018

This study aimed to investigate the association of the muscle activity around the neck of the operator(dental hygienists') according to the change in the patient's neck angle during a direct visual inspection on the maxillary right-side molar palatal surface. The operators were $4^{th}$ year dental hygiene students, who are future dentalhy gienists, having accurate understanding on and awareness of the location of the operation site, hand fixation, and how to use the tools. Data on the change in the muscle activity around the neck were collected by using surface electromyography and neck goniometer. SPSS statistics 20 was used for statistical analyses including Shapiro-wilk test and one-way ANOVA. As a result, the activities of the operator upper trapezius, cervical erector spinae, and levator scapulae muscles significantly decreased when the patient's head was angled compared to when it was not. For the angle of the operator head, the head bend significantly decreased when the patient's head was angled than when it was not. Based on the study results, it is expected that angling the patient's head when treating his or her teeth will decrease the excessive muscle activity around the neck of the operator, and will reduce muscle fatigue. Therefore, angling the head of the patient while treating his or her teeth is recommended. This suggests that muscle pain caused by repetitive actions in the wrong posture can be reduced.

• Journal of the Korea Convergence Society
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• v.10 no.3
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• pp.67-72
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• 2019

The purpose of this study was to analyze the effects of computer game usage time on trunk muscle thickness and pressure pain threshold. The 33 study participants were divided into Group A, which spent less than 10 hours per week playing computer games; Group B, which spent between 10 and 20 hours per week playing computer games; and Group C, which spent more than 20 hours per a week playing computer games. The thickness of the participants' upper trapezius (UT), pectoralis minor (PM), anterior scalene (AS), and middle scalene (MS) muscles as well as the pressure pain threshold of their UT, PM, AS, MS, and levator scapular (LS) were measured. The study found that the PM, AS, and MS muscle thickness in group C was significantly greater than in the other groups (p<.05), and the UT, AS, PM, and LS pressure pain threshold in group C was significantly lower than in other groups (p<.05). Therefore, those who use computers for a long period of time during the week should recognize that their computer usage may cause musculoskeletal disorders.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.47-53
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• 2024

Purpose : This study investigated the effects of concentric and eccentric contractions on muscle strength using an isokinetic dynamometer (ID) in college students in their 20s. It aimed to understand the impact of differences between the dominant and non-dominant sides on strength asymmetry and to elucidate the clinical implications of these differences to establish an appropriate posture and environment for patients. Methods : The experiment was conducted with 30 healthy adult participants. Prior to the experiment, participants underwent a warm-up targeting the shoulders, and efforts were made to eliminate factors that could potentially influence the measurement results. Subsequently, the maximum safe range of motion of shoulder joint abduction, extension, and flexion was measured using an isokinetic muscle function testing device. Muscle strength was assessed using concentric and eccentric contractions alternating between the dominant and non-dominant sides, and paired sample t-tests were used for the analysis. Results : There was no significant difference between bilateral peak torques for eccentric contraction in shoulder joint abduction, extension, and flexion (p>0.05). There was also no significant difference between bilateral peak torques for concentric contraction in shoulder joint abduction, extension and flexion (p>0.05). Conclusion : This study found no statistically significant difference in muscle strength between the dominant and non-dominant sides during concentric and eccentric contractions. However, previous studies have shown significant differences between the dominant and non-dominant sides during eccentric and concentric contractions during internal shoulder rotation in the general population, as well as significant differences in the upper trapezius muscle. Therefore, further research is needed to support the application of different intensities for bilateral muscle strengthening exercises in clinical practice.