• 국제물리치료학회지
• /
• 제9권4호
• /
• pp.1683-1686
• /
• 2018

Low back pain (LBP) is the most common reason for seeking physical therapy (PT) care. Recent studies suggest that axial loading can have a positive impact on the intervertebral disc by improving its tensile strength. Further, whole body vibration (WBV) appears to improve spinal muscle relaxation. Therefore, this case study describes the use of axial loading using a mini-trampoline in a female with chronic LBP. This case report is a single subject design. This patient is a 29-year-old female with a six-month history of low back pain following a motor vehicle accident. MRI found herniated discs at L4 and L5, clinical tests were positive for pain in the L4 and L5 dermatome and myotome the slump test was positive for neural tension, and LBP was constant at 4-6/10 over the past four months. She received axial loading exercises using a mini-trampoline and performed six sessions that were, scheduled twice a week for three weeks. Her Oswestry Disability Index (ODI) score improved from 40% at the time of her first visit to 22% at her final visit. Pain measure on the Numeric Pain Rating Scale (NPRS) after the first treatment was 7/10, and her pain after the final treatment was 0/10. These changes in the pain scores are clinically significant and exceed the minimal clinically important difference (MCID). This patient had a significant improvement in her pain using the NPRS and the ODI. This case study suggests that axial loading may be an effective treatment for some individuals with discogenic chronic low back pain.

• Geomechanics and Engineering
• /
• 제15권5호
• /
• pp.1061-1070
• /
• 2018

The main purpose of retaining wall methods for deep excavation is to keep the construction site safe from the earth pressure acting on the backfill during the construction period. Currently used retaining wall methods include the common strut method, anchor method, slurry wall method, and raker method. However, these methods have drawbacks such as reduced workspace and intrusion into private property, and thus, efforts are being made to improve them. The most advanced retaining wall method is the prestressed wale system, so far, in which a load corresponding to the earth pressure is applied to the wale by using the tension of a prestressed (PS) strand wire. This system affords advantages such as providing sufficient workspace by lengthening the strut interval and minimizing intrusion into private properties adjacent to the site. However, this system cannot control the tension of the PS strand wire, and thus, it cannot actively cope with changes in the earth pressure due to excavation. This study conducts a preliminary numerical analysis of the field applicability of the controllable prestressed wale system (CPWS) which can adjust the tension of the PS strand wire. For the analysis, back analysis was conducted through two-dimensional (2D) and three-dimensional (3D) numerical analyses based on the field measurement data of the typical strut method, and then, the field applicability of CPWS was examined by comparing the lateral deflection of the wall and adjacent ground surface settlements under the same conditions. In addition, the displacement and settlement of the wall were predicted through numerical analysis while the prestress force of CPWS was varied, and the structural stability was analysed through load tests on model specimens.

• Steel and Composite Structures
• /
• 제3권4호
• /
• pp.261-275
• /
• 2003

Truss members built-up with double angles back-to-back have monosymmetric cross-section and twisting always accompanies flexion upon the onset of buckling about the axis of symmetry. Approximate formulae for calculating the buckling capacity are presented in this paper for routine design purpose. For a member susceptible only to flexural buckling, its optimal cross-section should consist of slender plate elements so as to get larger radius of gyration. But, occurrence of twisting changes the situation owing to the weakness of thin plates in resisting torsion. Criteria for limiting the leg slenderness are discussed herein. Truss web members in compression are usually considered as hinged at both ends for out-of-plane buckling. In case one (or both) end of member is not supported laterally by bracing member, its adjoining members have to provide an elastic support of adequate stiffness in order not to underdesign the member. The stiffness provided by either compression or tension chords in different cases is analyzed, and the effect of initial crookedness of compression chord is taken into account. Formulae are presented to compute the required stiffness of chord member and to determine the effective length factor for inadequately constrained compressive diagonals.

• The Korean Journal of Physiology
• /
• 제4권2호
• /
• pp.19-24
• /
• 1970

Since the discovery of the muscle spindle by Hassall (1831), an intensive studies of its anatomical and physiological characteristics had been undertaken. Recent morphological studies of Boyd (1962) demonstrated that the muscle spindles have two different intrafusal muscle fibers, nuclear bag and nuclear chain fiber, and these intrafusal fibers are under independent motor innervation by ${\gamma}_1$ and ${\gamma}_2$ motor neurone. Neurophysiological studies of Hunt and Kuffler (1951) showed regulatory effect of ${\gamma}$ motor neurone upon the excitability of the spindle afferents. Harvey and Mathews (1961) observed the dynamic and static characteristics of the two different spindle afferents, the primary and secondary ending. Furthermore, Mathews (1962) postulated the functional existance of two kind of ${\gamma}$ motor neurones, namely, the dynamic and static fusimotor fiber. Recent report of Kim and Partridge(1969) pointed out that the descending vestibular signals had increased the slope of the length-tension relationship in stretch reflex; Kim (1967) demonstrated that the descending vestibular impulses act upon the stretch reflex loop through the ${\gamma}$ motor pathway. These experimental evidences from the morphological and neurophysiological studies on the muscle spindles support the concept that the stretch reflex action of the skeletal muscle operates as a negative feedback control system. The author had discussed the way by which the f system participates in the control of stretch relfex feed back system. that was taken for a prototype of posture and movement.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제23권4호
• /
• pp.348-356
• /
• 2001

The factors related to relapse in 20 skeletal class III patients who performed two-jaw surgery with Le Fort I maxillary osteotomy and bilateral sagittal split ramus osteotomy was investigated. All patients were fixed with miniplate on the maxilla and three screws at each mandible. Cephalograms taken at preoperative, immediate postoperative and 8 months postoperative after surgery were traced and digitized. 1.The horizontal and vertical relapse of maxilla and mandibular chin points was within 1mm postoperatively. Compare to the preceding report concerning the mandibular set-back surgery only group, this reveals two-jaw surgery for mandibular prognathism using rigid fixation is more stable. 2.Although there was no significant relapse tendancy was observed at chin points, the screw tip land-marks moves anterio-superiorly and each side of the screws moved as a one unit. The screw tip points moved similar direction to the masticatory force and this movements might be influenced by the muscular tension to the distal segment of the mandible. 3.According to the regression analysis, the amount of horizontal and vertical movement of mandibular set-back influenced the mandibular relapse. However, direction and amount of maxillary surgical movement did not inf1uenced the maxillary and mandibular relapse.

• The Journal of Korean Physical Therapy
• /
• 제29권6호
• /
• pp.307-315
• /
• 2017

Purpose: The purpose of this study was to investigate the effects of kinesio taping on lumbar flexibility onto erector spinae and sacroiliac joint. Methods: Sixty healthy adults (male=36, female=24) participated in this study and were randomly assigned to the experimental group that received kinesio taping onto erector spinae and sacroiliac joint (n=30) or the control group that received X-letter placebo taping onto them (n=30). Lumbar flexibility (flexion, extension, lateral flexion, and rotation) was measured using back range-of-motion instrument (BROM) II before and after taping. Results: In the change of lumbar flexibility after taping in the experimental group, there were statistically significant difference in flexion, lateral flexion, and rotation (p<0.05), but there was no significant difference in extension. There was no significant difference in the change of lumbar flexibility after taping in the control group. Conclusion: In conclusion, kinesio taping onto erector spinae and sacroiliac joint improved the joint function. Kinesio taping may reduce the muscle tension and facilitate the circulation of tissue fluid. In light of these results, it is thought that the application of kinesio taping had influence on an increase in lumbar flexibility. Therefore, kinesio taping will be able to be used as the method of the prevention of pain and the treatment in the lumbar region.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제12권1호
• /
• pp.943-956
• /
• 2020

In this study, the motion control problem of the vessel towed by a towing ship (tugboat) is considered. The non-powered towed ship is dragged by the towing ship. Even though the towed ship is equipped with propulsion systems, they cannot be used at low or constant speeds due to safety issues. In narrow canals, rivers, and busy harbor areas especially, where extreme tension is required during towing operation, the course stability of the towed vessel depends on the towing ship. Therefore, the authors propose a new control strategy in which the rudder system of the towed vessel is activated to provide its maneuverability. Based on the leader-follower system configuration, a nonlinear mathematical model is derived and a back-stepping control is designed. By simulation and experiment results with a comparison study, the usefulness and effectiveness of the proposed strategy are validated.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제12권1호
• /
• pp.354-366
• /
• 2020

This work mainly focuses on determination of the fully plastic J-integral solutions for welded center cracked plates subjected to remote tension loading. Detailed three-dimensional elasticeplastic Finite Element Analyses (FEA) were implemented to compute the fully plastic J-integral along the crack front for a wide range of crack geometries, material properties and weld strength mismatch ratios for 900 cases. According to the database generated from FEA, Back-propagation Neural Network (BPNN) model was proposed to predict the values and distributions of fully plastic J-integral along crack front based on the variables used in FEA. The determination coefficient R2 is greater than 0.99, indicating the robustness and goodness of fit of the developed BPNN model. The network model can accurately and efficiently predict the elastic-plastic J-integral for weld centerline crack, which can be used to perform fracture analyses and safety assessment for welded center cracked plates with varying strength mismatch conditions under uniaxial loading.

• Journal of the Korean Wood Science and Technology
• /
• 제27권3호
• /
• pp.82-90
• /
• 1999

송광사 삼세불화는 조성년도가 확실하지 않지만 남아있는 서기(書記)와 재질 분석을 통해 19세기초에 제작된 것으로 추정 할 수 있었다. 그리고 공시불화의 보존처리를 위해 안료층과 바탕층, 지지층을 구성하고 있는 재질을 분석하고 이에 적합한 지지층인 배첩지를 초지하여 그 적합성을 시험한 바 다음과 같은 결론을 얻었다. 1. 삼세불화의 단면구조는 안료층과 명주로 된 바탕층 그리고 한지(韓紙)로 이루어진 지지층으로 구성되어 있어 19세기 당시의 불화는 기본적으로 안료층, 바탕층, 지지층으로 구성되어 있음을 알 수 있었다. 또한 안료층과 바탕층의 접착은 아교를 사용하였고 지지층의 sheet 배첩은 호료(糊料)를 사용했음을 알 수 있었다. 2. 삼세불화의 지지층은 5겹으로 구성되어 있고 두 종류의 종이가 사용되었는데 바탕층과 접해 있는 1~2층은 순수한 닥섬유로 제조한 한지(韓紙)를 사용하였고 나머지 3개 층은 폐마섬유(廢麻纖維)에 닥섬유가 혼합된 종이를 사용하였다. 더 많은 자료가 확보되어야만 단언할 수 있지만 재질을 통해 당시의 상황을 파악해 보면 19세기 당시의 사회는 경제적으로 어려움을 겪고 있었고 더욱이 사찰 제지업은 피폐해져 운영이 어려워 후면에 사용한 배첩지는 질이 떨어지는 폐마를 이용 했을 것으로 추측되었다. 3. 본 재료의 바탕층과 지지층간의 인장력을 고려하여 새롭게 제조해 보수용으로 사용한 바 본 공시재료의 보수용 배첩지로서 적합했음을 알 수 있었다.

• 한국운동역학회지
• /
• 제13권1호
• /
• pp.95-108
• /
• 2003

The purposes of this study were to analyze the muscle activities and the characteristics of muscle recruiting patterns of upper trunk for Ssirum dutguri technique using three top-ranked elite Ssirum players. The EMG technique was used to record muscle activities of both right and left sides of latissimus dorsi, biceps brachii, and erector spinae. Six surface electrodes were placed on the surface of the selected muscles and one ground electrode was also attached on the back of neck(C7). One video camera was also used to record the Ssirum motion to define 4 events and 3 phases for further analysis. The raw EMG data were filtered with band pass filter (50-400 Hz) to remove artifacts and then low pass filtered (4 Hz) to find the linear envelope which resemble muscle tension curve. This filtered EMG data were normalized to MVIC for the purpose of comparion between the subjects. The results were indicated that each subject with different physical characteristics showed very different muscle activity patterns. Although Ssirum dutguri is considered as foot technique the player grasped opponent's satba(belt) with both hands when they play. Because of this reason, activities of upper trunk muscles were relatively high. However, direct comparison between upper and lower body muscles was not possible due to the lack of the data in present study. Interestingly, all threes subjects showed that erector spinae muscle activity was comparatively higher than those of latissimus dorsi and biceps brachii. This implies to reinforce back muscle as a routine of training to improve performance or to prevent back injury.