• Journal of the Korean Society of Safety
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• v.20 no.2 s.70
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• pp.169-174
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• 2005

Traditionally, keyboards have been one of the most frequently used input devices for information processing using computers. As most computers adopt the Microsoft Windows for their operating system however, the usage of mouse has recently increased to a great extent. Moreover, the mouse has been used as the leading input device in such areas as industrial design and computer aided design. Excessive uses of mouse may cause a severe pain and fatigue on neck and upper limb due to the intensive and repetitive use of corresponding muscles, which renders a decline in efficiency and leads to musculoskeletal disorders. The main purpose of this study is to find the best working conditions to prevent musculoskeletal disorders when using mouse in a neutral posture. Utilizing electromyogram amplitude and Borg's scale, the role change and strength imposed on the muscles were measured and analyzed with and without the forearm support concerned. Also investigated were the effects of changes in elbow forearm supporter.

• The Journal of Pediatrics of Korean Medicine
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• v.12 no.1
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• pp.133-143
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• 1998

Myofascial pain syndrome is one of the pain syndrome resulted from myofascia which covered muscles and clinically characteristic feature by sensitive trigger point in skeletal muscles and referred pain reactivated by stimulating each trigger point. The origin of headache are local lesion such as head, chest, abdominal organ, systemic lesion with fever or in toxic state. the other factors are consciousness, personality, anxiety, depression, which cause muscle strain in physiological environment. The Oriental Medical therapy for headache has herb medication and acupuncture. especially acupuncture therapy has not only classical systemic acupuncture(體鍼) but also neo-acupuncture(新鍼) such as commonly using auricular acupuncture(耳鍼) and manual acupuncture (手鍼), recently trigger point acupuncture is used. The author analyzed 27 cases of patient with headache treated by trigger point acupuncture therapy in Dong-yu Oriental Medical Hospital from March 1st 1997 to February 28th 1998. The following results were obtained. 1. The sex ratio of the female was 59.26%(16 cases) and male was 40.74%(11 cases), the ratio of high school student was 62.96%(17cases) as first. 2. The headache duration ratio of 2-3 years was 37.04%(10 cases) as first, 1-2 years was 25.93%(7 cases) as second. 3. The portion ratio of whole headache was 33.33%(9 cases) as first, lateral headache was 29.63%(8 cases) as second 4. The combined symptoms ratio of anorexia was 40.74%(11 cases) as first, fatigue was 33.33%(9 cases) as second, neck stiffness and dizziness was each 25.93%(7 cases) as third. 5. The therapeutic duration ratio of below 1 week was 29.63%(8 cases) as first, 2-3 weeks was 22.22%(6 cases) as second, 1-2 weeks and 3-4 weeks was each 18.52%(5 cases) as third. 6. The ratio of family history was 11 cases(40.74%). mother with headache was 6 cases, father was 3 cases, and brothers & sisters was 2 cases. 7. The herb medication ratio of Chungsanggyuntongtang(淸上?痛湯) was 37.04%(10 cases), Kamiondamtang(加味溫膽湯) was 22.22%(6 cases), Hyangsapyunguisan(香砂平胃散) was 18.25%(5 cases) etc. 8. The remedial effect ratio of good was 25.93%(7 cases), fair was 48.15%(13 cases), not improved was 7.41%(2 cases), side effect was 3.70%(1 cases), and unknown was 14.81%(4 cases).

• Journal of Biomedical Engineering Research
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• v.29 no.4
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• pp.316-322
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• 2008

The purpose of this study was to investigate muscle activation of lower extremity such as rectus femoris, tibialis anterior and soleus according to 0cm(bare foot), 4cm and 7cm heel height of shoe on the rocking surface in older women. 20 older women who did not have any lower musculoskeletal and neurological disorders in the past were participated in this study. Each subject was standing for 15 seconds on the level 8 of Biodex Stability System (BSS) while wearing 4cm and 7cm heel height shoes including bare foot. Electromyography was used to measure muscle activation of lower extremity, and the muscle activation was expressed as a percentage of maximal voluntary isometric contraction (% MVIC). We measured % MVIC of three muscles during 5 seconds except for the first 5 seconds and last 5 seconds. SPSS 12.0 program was used for this study. Repeated one-way analysis of variance(ANOVA) was performed to compare the significant difference among the muscles of lower extremities according to heel heights of shoe on the rocking plate. % MVIC of each muscle such as rectus femoris, tibialis anterior and soleus regarding heel heights of shoe had statistically significant differences (p<0.05). The results of contrast test were as follows; 1) % MVIC of rectus femoris had significant differences between barefoot and 4cm, and barefoot and 7cm. 2) % MVIC of tibialis anterior had significant differences between barefoot and 4cm, barefoot and 7cm, and 4cm and 7cm. 3) % MVIC of soleus had significant differences between barefoot and 7cm, 4cm and 7cm. The results indicate that all commonly responsive muscle on the conditions of barefoot, 4cm, and 7cm shoe height on the rcoking surface is tibialis anterior muscle. We found out that the more heels of shoe high, the more muscle activation increases. High-heeled shoes above 7cm remarkably increase the muscle activation of lower extremity and may result in muscle fatigue. Thus, these shoes may summate risk factors of falls in older women. We can acknowledge that the heels above 4 cm affect each muscle activation in lower extremity on the rocking surface.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.135-142
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• 2015

Human-powered self-generating devices have been attractive with its operation characteristic independent from outer environment such as weather condition and wind speed. However, conventional self-generators have low electric power output due to their weakly-coupled electromagnetic structure. More importantly, rotary crank motion which is usually adopted by conventional self-generator to generate electricity requires specific skeletal muscles to maintain large torque circular motion and consequently, causes fatigue on those muscles before it can generate enough amount of electricity for any practical application. Without improvement in electric power output and usability, the human-powered self-generator could not be used in everyday life. This study aims to develop a human-powered self-generator which realized a strong electromagnetic coupling in a closed-loop tubular structure (hula-hoop shape) for easy and steady long-term driving as well as larger electric output. The performance and usability of the developed human-powered generator is verified through experimental comparison with a commercial one. Additionally, human workload which is a key element of a human-powered generator but not often considered elsewhere, is estimated based on metabolic energy expenditure measured respiratory gas analyzer. Further study will focus on output and portability enhancement, which can contribute to the continuous power supply of mobile equipments.

• Journal of Convergence for Information Technology
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• v.11 no.3
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• pp.250-260
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• 2021

The purpose of this study is to investigate muscle function and symmetry index during whole body vibration exercise using lower extremity training posture for throwing athletes. For throwing athletes in their 20s(6 males, 4 females, age: 24.60±0.92years, height: 177.90±7.40cm, weight: 92.90±22.97kg), lower extremity training postures with squat, carphrase, and lunge movements. Whole body vibration exercise training was performed using. Tensiomyography(TMG) variables Time Delay(Td), Time Contraction(Tc), Time Sustain(Ts) Time Relaxation(Tr), and Displacement Maximumal(Dm) in the lower extremity joint muscles(biceps femoris(BF), gastrocnemius lateral(GL), gastrocnemius medial(GM), rectus femoris(RF), tibialis anterior(TA), lateral vastus(LV), medial latissimus(ML)), were measured to compare and analyze muscle activity, muscle fatigue, and left-right symmetry. The results of the study are left RF, VL, right VM (p<.05) in Td, VM (p<.05) in Tc, GM in Ts (p<.05), left RF in Tr, and right TA (p<. 05) showed a change. Therefore, it has been proven that various whole-body vibration training is an effective exercise with changes in muscle contraction, and stability of the core is secured by symmetry of the left and right muscles. For this reason, the whole body vibration exercise will have a positive effect on rehabilitation training, and it is believed that it will be able to improve performance.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.3
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• pp.799-807
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• 2016

The objective of research was to explore the effects of Kinesic taping treatment on Kayaker's athletic performance and muscle fatigue variable. In order to accomplish such study objective, this study employed 8 ordinary university students and 8 university kayaker's as study subjects. The athletic performance records and blood lactate were analyzed before and after Kinesic taping treatment (KTT). Kinesic taping treatment was applied to the regions of agonist such as vastus medialis muscle, Latissimus dorsi muscle, Trapezius muscle, Biceps brachii muscle, and Triceps brachii muscle, which are major muscles for Kayaker's. Records for rest heart rate, athletic performance and blood lactate were measured upon 200m and 500m distance exercise using kayak ergometer. Data were analyzed by SPSS 19.0 using paired t-test and one-way repeated ANOVA at significant level of a = .05. First, performance records of 200m paddling kayak showed that the ordinary university students had a mean score of 60.13 second before and 58.75 second after kinesic taping treatment. University kayakers had a mean score of 58.75 second before and 53.0 second after kinesic taping treatment. Both groups had significant differences between before and after KTT in the athletic performance. In addition, levels of blood lactate showed that the ordinary university students had a mean score of 5.89mM before and 8.90mM after KTT and university kayaker's had a mean score of 5.79mM before and 8.48mM after KTT. The ANOVA showed that the level of ordinary university students' blood lactate was significantly higher than university kayakers only after KTT. Second, performance records of 500m paddling kayak showed that the ordinary university students had a mean score of 2.90 minute before and 2.77 minute after KTT and university kayaker's had a mean score of 2.30 minute before and 2.20 minute after KTT. Both groups had significant differences between before and after KTT in the athletic performance. Moreover, only university kayaker's had a significantly higher performance record than the counterpart. Levels of blood lactate showed that the ordinary university students had a mean score of 7.71mM before and 8.85mM after KTT and university kayakers had a mean score of 8.09mM before and 8.45mM after KTT. However, such a level of increase had no significant difference between the groups

• Journal of Korean Physical Therapy Science
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• v.3 no.4
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• pp.207-214
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• 1996

Main cause of low back pain is a poor posture. Most low back pains are due to a poor posture. The poor posture induces muscle tension and finaliy low back pain. The poor posture arehabitually trained from the childhood by the environmetal factors. In general, maintaining good posture during working and sleeping hours are the first line of defence against back pam. (1) Supine posture is the easiest posture that relaxes and fixes muscles. Supine posture is thus a starting position for on exercise. Lying down releases the weight pressures of head and shoulder and thus body can be relaxed and extended which are helpful for treating back pain. However, supine posture can increase the pressure in ribcage posture aspect and disphragram due to visceral oragans. (2) Sitting in one position for a long time results in fatigue and relaxation of spinal muscies. Finally, body strength is weakened and sitting posture will become poor. If this poor posture continues for a longer time, pain will be accompanied due to overelongation of muscle ligaments. The habitual poor posture could induce intervertebral disc distortion. If the intervertebral disc is damaged, sitting in one position or movement causes pain. (3) Abnormal lumbar curve induces the tention of abdominal muscle and paravertebral muscle groups as well as tention of lower limb muscle group connected to pelvis. For a person with weak body strength, muscle relaxation increases curvature in lumbar, chest and cervical regions. This will induce a pelvic anterior tilting of the imaginary line between A. S. I. S. and P. S. I. S. Hip joint extensor muscle acts on releasing the pelvic anterior tilting. Contrections of hamstring muscle and femoral muscle recover the imaginary line between A.S.LS. and P.S.I.S. from pelvic anterior tilting. thus, contraction of rectus abdominis muscle are required to maintain the normal lumbar curve.

• Journal of Chest Surgery
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• v.27 no.7
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• pp.610-616
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• 1994

Myasthenia gravis is a rare condition, affecting only 1/75000. It is characterized by weakness and fatigue of the voluntary muscles due to impaired neuromuscular transmission at the acetylcholine receptor site. It is probably caused by an autoimmune mechanism leading to reduction of the available nicotinic acetylcholine receptors at the neuromuscular junction. A relationship between the thymus and myasthenia gravis was suggested by Weigert in 1901, and Blalock was the first to report the efficiency of thymectomy in the treatment of myasthnia gravis in 1939. Since that time, thymectomy has become increasingly important in managing patients with myasthenia gravis. Fourteen patients with myasthenia gravis underwent thymectomy between September 1987 and March 1994 and got the following results; 1. The sex distribution was 10 females and 4 males with ages ranging from 15 to 51 years[mean, 34.8 years]. 2. Clinical manifestation of ocular symptoms were seen in all cases, dysphagia in 12[85.7%], extremity weakness in 11 [78.6 %], and dyspnea in 3 [21.4 %]. 3. According to the modified Osserman`s classification, 8 patients were in group IIb, 3 in IIa, 2 in I and 1 in IIc, respectively. 4. Histopathologic examination of the resected thymuses revealed hyperplasia in 8 patients, benign thymoma in 3, and malignant thymoma in 3. 5. There were no perioperative or immediate postoperative deaths but one patient died about two months after the thymectomy due to respiratory failure. 6. During the follow-up period, 11 patients [78.6 %] showed clinical improvement. Among them, 4 cases [28.6 %] showed complete remission, 3 [21.4 %] showed marked improvement, and 4 [28.6 %] showed subjective improvement. 7. Among the 8 patients with thymic hyperplasia, clinical improvement was noticed in 7 patients 5 %]. Among the 6 patients with thymoma, 4 patients [66.7 %] showed improvement.

• Journal of Oral Medicine and Pain
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• v.38 no.3
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• pp.261-266
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• 2013

Myofascial pain is a condition associated with regional pain and muscle tenderness characterized by the presence of myofascial trigger points. In this case report, a subject complaining of nighttime bruxism was clinically assessed, and a latent trigger point of the anterior temporalis muscle was identified with manual palpation. A surface electromyographic (SEMG) exam of the anterior temporalis muscle harboring the latent trigger point demonstrated several SEMG features, including post-contraction irritability, delayed relaxation following contraction and accelerated muscle fatigue. It was concluded that a SEMG exam may detect abnormal masticatory muscle function and, therefore, assist in the evaluation of myogenous temporomandibular disorders.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.113-119
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• 2010

The purpose of this study was to determine the difference of the pinch strength according to testing posture(standing and sitting) and elbow flexion degree($0^{\circ}$, $45^{\circ}$, $90^{\circ}$ and $135^{\circ}$). Forty normal young adults(male: 20, female: 20, mean age: $22.68{\pm}2.91$ years) participated in this study. The methods of this study were categorized as follows: 1) One set of measurement was performed on four elbow flexion degrees($0^{\circ}$, $45^{\circ}$, $90^{\circ}$ and $135^{\circ}$) in two testing postures(standing and sitting) and all subjects were measured for 3 sets testing procedures in every experimental sessions. 2) Pinch strength in various elbow flexion degree was measured after 2 min rest time, and then each test set was repeatedly performed with 5 min rest time to prevent fatigue of muscles involved in the elbow joint. The result was obtained as follow: 1) In standing posture, there was statistically significant difference at $0^{\circ}$ and $45^{\circ}$, $0^{\circ}$ and $90^{\circ}$, $0^{\circ}$ and $135^{\circ}$, $45^{\circ}$ and $90^{\circ}$, $45^{\circ}$ and $135^{\circ}$, $90^{\circ}$ and $135^{\circ}$. 2) In sitting posture, there was statistically significant difference at $0^{\circ}$ and $45^{\circ}$, $0^{\circ}$ and $90^{\circ}$, $0^{\circ}$ and $135^{\circ}$, $45^{\circ}$ and $90^{\circ}$, $45^{\circ}$ and $135^{\circ}$, $90^{\circ}$ and $135^{\circ}$. 3) Statistically, there was no significant difference between standing and sitting posture in same elbow flexion degree, however pinch strength in standing posture was higher than sitting posture.