• Title/Summary/Keyword: Physical Cause

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Effects of Fatigue in the Non-paretic Plantarflexor on the Activities of the Lower Leg Muscles during Walking in Chronic Stroke Patients (만성 뇌졸중 환자의 비마비측 발바닥굽힘근 근피로가 보행 시 양측 하지 근육의 활성도에 미치는 영향)

  • Lee, Jae-Woong;Koo, Hyun-Mo
    • Journal of the Korean Society of Physical Medicine
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    • v.14 no.3
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    • pp.127-133
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    • 2019
  • PURPOSE: The aim of this study was to obtain detailed and quantified data concerning the effects of plantarflexor fatigue induced to the non-paretic side on muscle activities of the bilateral lower extremities during walking in chronic stroke patients. METHODS: In this study, chronic stroke patients were evaluated for six months after the onset of stroke. To induce the non-paretic plantarflexor fatigue, 20 chronic stroke patients were asked to perform their given fatigue affecting assignments, which were presented in a forced contraction fatigue test method, until the range of motion of the plantarflexor was reduced to less than 50%. The muscle activities of the rectus femoris, tibialis anterior and gastrocnemius in the paretic and non-paretic lower extremities were measured using a wireless surface EMG before and after muscle fatigue induction. RESULTS: The findings showed that after plantarflexor fatigue was induced on the non-paretic side, a significant decrease in muscle activities of the rectus femoris on the paretic side was noted (p<.05). The muscle activities of the tibialis anterior and gastrocnemius were also observed to decrease, but, these results were not statistically significant (p>.05). In the non-paretic side, there was a significantly decrease in the muscle activities of the rectus femoris, tibialis anterior, and gastrocnemius (p<.05). CONCLUSION: These finding suggest that the muscle fatigue of the non-paretic plantarflexor affects not only the muscle activity of the ipsilateral lower extremity but also the muscles activity of the contralateral lower extremity. This highlights the necessity of performing exercise or training programs that do not cause muscle fatigue in clinical aspects.

Failure pattern of large-scale goaf collapse and a controlled roof caving method used in gypsum mine

  • Chen, Lu;Zhou, Zilong;Zang, Chuanwei;Zeng, Ling;Zhao, Yuan
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.449-457
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    • 2019
  • Physical model tests were first performed to investigate the failure pattern of multiple pillar-roof support system. It was observed in the physical model tests, pillars were design with the same mechanical parameters in model #1, cracking occurred simultaneously in panel pillars and the roof above barrier pillars. When pillars 2 to 5 lost bearing capacity, collapse of the roof supported by those pillars occurred. Physical model #2 was design with a relatively weaker pillar (pillar 3) among six pillars. It was found that the whole pillar-roof system was divided into two independent systems by a roof crack, and two pillars collapse and roof subsidence events occurred during the loading process, the first failure event was induced by the pillars failure, and the second was caused by the roof crack. Then, for a multiple pillar-roof support system, three types of failure patterns were analysed based on the condition of pillar and roof. It can be concluded that any failure of a bearing component would cause a subsidence event. However, the barrier pillar could bear the transferred load during the stress redistribution process, mitigating the propagation of collapse or cutting the roof to insulate the collapse area. Importantly, some effective methods were suggested to decrease the risk of catastrophic collapse, and the deep-hole-blasting was employed to improve the stability of the pillar and roof support system in a room and pillar mine.

Physical protection system vulnerability assessment of a small nuclear research reactor due to TNT-shaped charge impact on its reinforced concrete wall

  • Moo, Jee Hoon;Chirayath, Sunil S.;Cho, Sung Gook
    • Nuclear Engineering and Technology
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    • v.54 no.6
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    • pp.2135-2146
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    • 2022
  • A nuclear energy facility is one of the most critical facilities to be safely protected during and after operation because the physical destruction of its barriers by an external attack could release radioactivity into the environment and can cause harmful effects. The barrier walls of nuclear energy facilities should be sufficiently robust to protect essential facilities from external attack or sabotage. Physical protection system (PPS) vulnerability assessment of a typical small nuclear research reactor was carried out by simulating an external attack with a tri-nitro toluene (TNT) shaped charge and results are presented. The reinforced concrete (RC) barrier wall of the research reactor located at a distance of 50 m from a TNT-shaped charge was the target of external attack. For the purpose of the impact assessment of the RC barrier wall, a finite element method (FEM) is utilized to simulate the destruction condition. The study results showed that a hole-size of diameter 342 mm at the front side and 364 mm at the back side was created on the RC barrier wall as a result of a 143.35 kg TNT-shaped charge. This aperture would be large enough to let at least one person can pass through at a time. For the purpose of the PPS vulnerability assessment, an Estimate of Adversary Sequence Interruption (EASI) model was used, which enabled the determination of most vulnerable path to the target with a probability of interruption equal to 0.43. The study showed that the RC barrier wall is vulnerable to a TNT-shaped charge impact, which could in turn reduce the effectiveness of the PPS.

A Comparison Study of Cervical Flexion-Relaxation Ratio in the Normal and Forward Head Postures

  • Yeo, Sang-Seok;Kwon, Jung-Won
    • The Journal of Korean Physical Therapy
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    • v.32 no.6
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    • pp.378-382
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    • 2020
  • Purpose: This study aimed to examine the effects of forward head posture on the flexion-relaxation ratio (FRR) and muscle activity during sustained neck flexion and to investigate the correlation between craniovertebral angle and FRR. Methods: Nineteen subjects participated in this study and were allocated to a forward head posture (FHP) group or a non-forward head posture (NFHP) group. Craniovertebral angle (CVA) and FRR were measured in all subjects, and all participants performed a standardized cervical flexion-extension movement in two phases: Phase I, sustained cervical full flexion for 5s; and Phase II, cervical extension with the return to the starting position for 5s. The value of CVA has calculated three times, and the value of FRR was measured three times in order to obtain the mean value. Results: FRR values in the FHP and NFHP group were significantly different (p<0.05). Phase I was significantly different, but the Phase II was not significantly different between the FHP and NFHP group (p>0.05). There was a significant correlation between the muscle activity of Phase I and CVA (p<0.05). However, FRR and the muscle activity of the Phase II were not a significant correlation with the CVA (p>0.05). Conclusion: FHP increases the muscle activity of the cervical erector spinae during sustained neck flexion and reduces FRR, which can cause fatigue in the cervical erector spinae. In addition, for those with a smaller CVA, muscle activity of the cervical erector spinae is increased during sustained neck flexion, which can increase neck muscle tension.

Self-Exercise Oriented Management for Shoulder Pain Patient with Winging Scapular : Case Report (견갑골 익상을 동반한 어깨 통증 환자에 대한 자가 운동 중심의 관리: 사례 보고)

  • Jeon, Jae-guk;Jung, Min-keun
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.28 no.2
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    • pp.67-75
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    • 2022
  • Background: Scapular winging is a rare disorder that is commonly caused by nerve damage of the dorsal scapular nerve, spinal accessory nerve, or the long thoracic nerve. This affects the scapulohumeral rhythm which may cause abnormal kinetic motion of the shoulder. The purpose of this case report is to describe a self-exercise oriented management incorporating shoulder strengthening to reduce symptoms in a shoulder pain patient with winging scapular. Methods: A 45 year old male patient complained of pain in his both shoulders without any trauma. Shoulders were treated with steroid injections for supraspinatus tendonitis, but although pain improved to some extent, pain and disability continued for 3 months. Both shoulders had pain, decreased active range of motions, muscles weakness, and scapular winging. The patient underwent 9 interventional sessions over 3 months and was managed mainly by self-exercise. The intervention method involved push up plus, sling, muscle strengthening, and stabilization exercises. Loads were increased as symptoms improved. Results: Clinical outcomes were measured at every session. Pain in both shoulders reduced to 0 on a numerical pain rate scale by the 4th session, and the active range of motion was fully recovered. During the 9th session, the strength of the serratus anterior had improved from grade P to G on the right side and grade G to N grade on the left. Conclusion: In this case study, the self-exercise program was effective in reducing pain, increasing active range of motion, and improving muscle strength in subjects with scapular winging.

Effects of Passive Scapular Stabilization on Upper Extremity Muscle Strength in Patients With Rotator Cuff Repair

  • Won-jeong Jeong;Duk-hyun An;Jae-seop Oh
    • Physical Therapy Korea
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    • v.30 no.1
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    • pp.41-49
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    • 2023
  • Background: Scapular dyskinesis may cause not only rotator cuff (RC) tear but also weakness of the upper extremity, studies on scapular dyskinesis that may occur after RC repair is still lacking. Objects: To determine whether scapular dsykinesis was present in patients after arthroscopic RC repair and to investigate the influence of passive scapular stabilization on upper extremity strength. Methods: A total of 30 patients after RC repair participated in this study. To compare the scapula of the arthroscopic RC repair shoulder and the contralateral shoulder, the winged scapula (WS) was measured using a scapulometer and scapular dyskinesis was also classified by type. Fixed instruments for muscle strength measurements were used to measure upper extremity muscle strength differences depending on passive scapular stabilization position or natural scapular position. A chi-square test, an independent t-test and a 2-way mixed measures analysis of variance (ANOVA) was used as statistical analysis. In analyses, p < 0.05 was deemed to be statistically significant. Results: Postoperative shoulder had a significant association with scapular dyskinesis and the WS compared to the contralateral shoulder (F = 0.052, p < 0.01). Postoperative shoulder, muscle strength in the shoulder abduction (p < 0.01), elbow flexion (p < 0.01) and forearm supination (p < 0.05) were significantly greater in the scapular stabilization position than in the scapular natural position. Conclusion: Patients underwent arthroscopic RC repair had a significant association with scapular dyskinesis and muscle strength was improved by a passive scapular stabilization position, therefore scapular stabilization is important in rehabilitation program.

Comparison of the Ratio of Thicknesses of the Rhomboid Major and Middle Trapezius Muscles While Performing Scapular Retraction Exercises (어깨뼈 뒤 당김 운동 방법에 따른 큰마름근과 중간등세모근의 근두께비의 비교)

  • Park, Heon-mi;Kim, Suhn-yeop
    • Physical Therapy Korea
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    • v.29 no.2
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    • pp.131-139
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    • 2022
  • Background: Shoulder impingement syndrome, a major cause of shoulder pain, involves weakness of the scapular retractor muscles. The major scapular retractor muscles are the middle trapezius and rhomboid major muscles; however, the latter is excluded in most studies. Objects: We aimed to measure the thickness of the middle trapezius and rhomboid major muscles using an ultrasonic diagnostic imaging system while performing four different shoulder retraction exercises and comparing the thicknesses and ratio of the thicknesses of these muscles. Methods: The thickness of the middle trapezius and rhomboid major muscles was measured in 24 healthy adults using ultrasound. Muscle thickness was measured three times in the Reference posture and four times while performing four different exercises that involved scapular retraction. The averages and standard deviations of the measured muscle thicknesses were obtained and compared. The ratio of muscle thickness and rate of changes in muscle thickness between the reference posture and the four exercises were compared. Results: For both, male (n = 10) and female (n = 14), there was a significant difference in the thickness of the middle trapezius muscle between the reference posture and the four exercises (p < 0.05) and in the thickness of the middle trapezius and rhomboid major muscles between male and female (p < 0.05); however, there was no significant difference in the ratio of the thicknesses of these muscles. Although a significant difference in the rate of change in muscle thickness during the four exercises was noted, there was no significant difference in the ratio of change in muscle thickness. Conclusion: This study demonstrates the ratio of the thicknesses of the middle trapezius and rhomboid major muscles and the rate of change in their thickness during exercises involving scapular retraction in healthy people in their 20s-30s.

Effects of the Explanations of Physical Phenomena Given in Non-Physics Textbooks on the Formation of Students' Physical Conceptions (물리 외 교과서에 제시된 물리적 현상 설명이 학생들의 물리 개념 형성에 미치는 영향)

  • Park, Mi-Jin;Kim, Young-Min
    • Journal of The Korean Association For Science Education
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    • v.23 no.2
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    • pp.155-164
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    • 2003
  • The purpose of the current study was to investigate the effects of explanations about physical phenomena given in non-physics textbooks on the formation of student physical conceptions. Two classes, 39 students in each, were sampled from two middle schools in Pusan, Korea, and two kinds of test tools for investigating student conceptions were developed for the study. The first test tool(a) investigated student conceptions after reading explanations about physical phenomena in non-physics textbooks, while the second(b) investigated student conceptions after reading explanations revised by physics education experts about the same physical phenomena. The two test tools were applied to each class, and for a fair invetigation, test(a) followed by test(b) was applied to one class, while test(b) followed by test(a) was applied to the other class. The results were as follows: In both classes, the students' level of understanding from explanations revised by physics education experts was significantly (p < .01) higher than that from explanations in non-physics textbooks. As such, it is feasible that false or inappropriate explanations in non-physics textbooks can cause student misconceptions. Moreover, the improper expression of physical science concepts, improper choice of scientific terms, and incorrect grammatical structures, along with the use of unsuitable examples and improper model pictures can make it difficult for students to understand physics concepts. Furthermore, differences in the terms used in physics textbook and those used in other textbooks can also confuse students' learning.

Need of Dormitory Environment Improvement and School-life Stress in the Special-purpose high school according to Residential Satisfaction in Dormitory and Housing (기숙사와 자가의 주거환경 만족도에 따른 특목고의 기숙사 환경개선 요구도 및 학교생활 스트레스)

  • Jin, Ae-Soon;Jang, Yoon-Ok
    • Journal of the Korean housing association
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    • v.20 no.4
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    • pp.89-102
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    • 2009
  • The purpose of this study is to investigate the influence the need for improvements to dormitory environments and to study the stress from school-life according to residential satisfaction in dormitories and housing. For the purpose of this study, a survey was conducted including a questionnaire consisting of a residential satisfaction scale, a need of dormitory environment improvement scale, and a school-life stress scale. The subjects were 453 special purpose students in Daegu and Gyeongsangbuk-do who all live in a dormitory. Factor analysis, Cronbach' α and MANOVA were employed for data analysis, and Scheffe test was used for post-hoc analysis. First, the lower group the satisfaction of a physical residential environment in a dormitory, the more likely it is that the dormitory environment need improvement. The result of this study suggests that dormitory students are much more sensitive to conditions relating to physical residential satisfaction than to sociopsychological residential satisfaction. Also, the residents believe that change to these physical residential conditions facilitate an improvement to sociopsychological residential satisfaction. Moreover, when the satisfaction of a physical residential environment is lower group, more perceptive stress occurs from academic, health and personal factors while a lower satisfaction for the sociopsychological residential environment results in a more perceptive stress from the environment. The result of this study suggests that dormitory conditions indicate the necessity of improving the environment to adapt well to school-life, thus reducing stress. Also when simply providing a supplementary physical residential environment the sociopsychological residential environment should be considered, as this can cause conflicts between roommates. Second, the lower group the satisfaction for a physical residential environment in housing, the more likely it is that the dormitory environment need improvement. The result of this study suggests that for environments of inadequate housing there is a strong urge towards needing more independence and a better living environment. Third, when group feel there is a more substantial difference in the physical residential environment between dormitories and housing, it is more likely it is that the dormitory environment need to be improved. Also, when they feel there is more substantial difference in the sociopsychological residential environment between dormitories and housing, a more perceptive stress is detected from the environment. The result of this study suggests that dormitory students want to have the same level of conditions as those provided in housing. Also, dormitory students want to need more physical environment improvement than sociopsychological environment improvement.

Clinical aspects of injury and acute poisoning in Korean pediatric patients (소아의 응급질환 - 우리나라 소아 및 청소년의 손상과 급성 중독을 중심으로 -)

  • Lee, Mi Jin;Park, Joon Seok
    • Clinical and Experimental Pediatrics
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    • v.51 no.2
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    • pp.116-121
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    • 2008
  • Unintentional injuries are the most important cause of morbidity and mortality in the pediatric population, and the home is the most common site of injury for children in Korea. The most common cause of injury was slip down. Fall down and burn were frequent in infant/toddlers group, automobile and bicycle accident more frequent in preschool children. Findings from the survey could then be used to provide targets for direct educational efforts by medical services and to direct environmental safety modifications tailored to the unique situation of each family. Pediatric toxic ingestions are treated commonly by pediatricians and emergency physicians. Significant injury after these ingestions is infrequent, but identifying the dangerous ingestion is sometimes a difficult task. By performing a detailed history, focused physical examination, and directed laboratory evaluation, an estimation of risk can be developed. According to recent Korean poison papers, there were bimodal peak of age distribution in poisoned children patient on the whole: infant and adolescents group. Various types of materials belonged the classes of drugs, household products, and industrial solvents. Most of the poisoned children patients had been poisoned accidentally, while most cases of adolescents poisoning had been intentional. More than half of the adolescents group had a suicidal purpose in Korea, so an understanding of the demographic factors associated with self-harm poisoning may provide useful information to improve prevention and treatment strategies.