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  • Title/Summary/Keyword: Lateral Rotation

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Factor Affecting Mandibular Rotational Troque Movements (하악의 비틀림회전운동에 영향을 미치는 요인)

  • 이유미;한경수;허문일
    • Journal of Oral Medicine and Pain
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    • v.23 no.2
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    • pp.143-155
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    • 1998
  • This study was performed to investigate the factor that might affect mandibualr body rotation. For the study, 115 patients with temporomandibular disorders and 35 dental students without angy signs and symptoms of temporomandibular disorders were randomly selected as the patient group and the contreol group, respectively. Preferred chewing side, Angle' classification, lateral guidance pattern, and affected side were clinically recorded, and the amount of Mandibular body rotational torque movement was measured in wide opening and closure, in right and left excursion with vertical and lateral distance in frontal plane, right and left rotational angel in horizontal and in frontal plane. Masticatory muscle activity of anteriorocclusal contact pattern on maximal hard biting were also observed synchronously with BioEMG and T-Scan , respectively. The observed items were muscle activity of anterior temporalis and superficial masseter, and tooth contact status related to contact number, force, duration, and occlusal unbalance between right and left arch. The data collected were analyzed by SAS statistical program. The results of this study were as follows : 1. Mean value of vertical distance in frontal plane in wide opening and closure was more in control subjects than in patients, but there was no difference for rotational angle. In right excursion, rotational angles were greater in patient group than in control group. 2. Comparison among the subjects by preferred chewing side did not reveal any significant difference, but comparison among patients by affected side showed more rotational amount in bilaterally affected patients than in unilaterally affected patients. 3. Comparison among the subjects by Angle's classification or lateral guidance pattern revealed no difference. There was also no difference between preferred chewing side and contralateral side, and between affected side and contralateral side. 4. Positive correlation in madibular rotational torque movements were observed among vertical distance, total horizontal rotation angle, electromyographic activity of anterior temporalis, tooth contact number, and tooth contact force but total frontal rotation angle almost did not show any correlation with other variables except vertical distance.

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Investigation on the responses of offshore monopile in marine soft clay under cyclic lateral load

  • Fen Li;Xinyue Zhu;Zhiyuan Zhu;Jichao Lei;Dan Hu
    • Geomechanics and Engineering
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    • v.37 no.4
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    • pp.383-393
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    • 2024
  • Monopile foundations of offshore wind turbines embedded in soft clay are subjected to the long-term cyclic lateral loads induced by winds, currents, and waves, the vibration of monopile leads to the accumulation of pore pressure and cyclic strains in the soil in its vicinity, which poses a threat to the safety operation of monopile. The researchers mainly focused on the hysteretic stress-strain relationship of soft clay and kinds of stiffness degradation models have been adopted, which may consume considerable computing resources and is not applicable for the long-term bearing performance analysis of monopile. In this study, a modified cyclic stiffness degradation model considering the effect of plastic strain and pore pressure change has been proposed and validated by comparing with the triaxial test results. Subsequently, the effects of cyclic load ratio, pile aspect ratio, number of load cycles, and length to embedded depth ratio on the accumulated rotation angle and pore pressure are presented. The results indicate the number of load cycles can significantly affect the accumulated rotation angle of monopile, whereas the accumulated pore pressure distribution along the pile merely changes with pile diameter, embedded length, and the number of load cycles, the stiffness of monopile can be significantly weakened by decreasing the embedded depth ratio L/H of monopile. The stiffness degradation of soil is more significant in the passive earth pressure zone, in which soil liquefaction is likely to occur. Furthermore, the suitability of the "accumulated rotation angle" and "accumulated pore pressure" design criteria for determining the required cyclic load ratio are discussed.

Truss Models for Deformation Analyses of RC Members (트러스 모델을 이용한 RC 부재의 변형 해석)

  • 홍성걸;이수곤
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.201-206
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    • 2001
  • This paper presents truss model that can be used to determine the deformation as well as strength of RC members. This model is constituted to address plastic hinge rotation at tile deformation concentrated regions under severe lateral load. The behavior of each element of truss model is evaluated on the basis of stress field analysis. The deformation is obtained by combining element deformations with joint rotation. Initial strength is calculated at the first failure of any element, and strength deterioration after failure depends on the strength reduction of this element. The proposed model will provide useful tools in seismic design of ductility-required members.

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The Effect of Tensor Fasciea Latae Length on the Rotation of Pelvic during One Leg Stance (대퇴근막장근의 길이가 한발서기 시 골반의 회전에 미치는 영향)

  • Kim, Byoung-Kon;Son, Jung-Hee
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.15 no.2
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    • pp.63-68
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    • 2009
  • Purpose : The purpose of this study was to investigate the effect of tensor fasciae latae length on the rotation of pelvis during one leg stance. Methods : 41 healthy adults participated in this study. The movement of the pelvis and trunk was measured using 3-dimensional motion analyzer, during one leg stance. The movement of the pelvis and trunk was collected lateral shift, rotation, side bending, and flexion-extension. Tensor fasciae latae length of subjects was measured in sidelying positon with neutral position of hip joint and flexion 90 of knee. Also, the range of motion of hip exteral and interal rotaion were measured in prone position wih lexion 90 of knee. The subjects were separated 2 groups that more pelvic rotation group(n=15) and less pelvic rotation group(n=15) according to the degree of pelvic rotation. Results : The more pelvic rotation group was showed significantly higher in the ROM of hip external rotation than less pelvic rotation group(p<0.05). The difference of tensor fasciae latae length not showed significant difference between groups. During one leg stance, The movement of the shifting and flexion-extension of trunk and pelvis were not showed significant difference. But the side bending and the rotation of pelvis and trunk showed significant difference between groups. Conclusion : The difference of tensor fasciae latae length not showed significantly in more pelvic rotation group and less pelvic rotation group. But, this study suggests that the pelvis instability brings the instability of the trunk during one leg stance.

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The Impact of Abdominal Drawing-in Maneuver and Tensor Fasciae Latae-iliotibial Band Self-stretching on Lumbopelvic Kinematics in Individuals With Lumbar Extension Rotation Syndrome

  • One-bin Lim;Oh-yun Kwon;Heon-seock Cynn;Chung-hwi Yi
    • Physical Therapy Korea
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    • v.31 no.1
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    • pp.79-88
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    • 2024
  • Background: The abdominal drawing-in maneuver (ADIM), a method of lumbar stabilization training, is an effective neuromuscular intervention for lumbar instability associated with low back pain (LBP). Objects: The purpose of this study was to compare the effect of a 2-week period of the ADIM and tensor fasciae latae-iliotibial band (TFL-ITB) self-stretching on lumbopelvic rotation angle, lumbopelvic rotation movement onset, TFL-ITB length, and pain intensity during active prone hip lateral rotation. Methods: Twenty-two subjects with lumbar extension rotation syndrome accompanying shortened TFL-ITB (16 males and 6 females) were recruited for this study. The subjects were instructed how to perform ADIM training or ADIM training plus TFL-ITB self-stretching program at home for a 2-week period. A 3-dimensional ultrasonic motion analysis system was used to measure the lumbopelvic rotation angle and lumbopelvic rotation movement onset. An independent t-test was used to determine between-group differences for each outcome measure (lumbopelvic rotation angle, lumbopelvic rotation movement onset, TFL-ITB length, and pain intensity). Results: The results showed that ADIM training plus TFL-ITB self-stretching decreased the lumbopelvic rotation angle, delayed the lumbopelvic rotation movement onset, and elongated the TFL-ITB significantly more than did ADIM training alone. Pain intensity was lower in the ADIM training plus TFL-ITB self-stretching group than the ADIM training alone group; however, the difference was not significant. Conclusion: ADIM training plus TFL-ITB self-stretching performed for a 2-week period at home may be an effective treatment for modifying lumbopelvic motion and reducing LBP.

Surgical Treatment of the Upshoot and Downshoot in Duane's Retraction Syndrome (안구후퇴의 증후군에 있어서 상전 및 하전에 대한 수술요법)

  • Kim, Myung-Mi
    • Journal of Yeungnam Medical Science
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    • v.6 no.2
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    • pp.127-132
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    • 1989
  • The upshoot and downshoot in Duane's retraction syndrome is believed to be related to a leash effect from the lateral rectus muscle. When the eye is rotated into the adducted position, the lateral rectus muscle slips over the globe, producing the up-and downshoot on adduction. The splitting of the ends of the lateral rectus into a Y configuration prevents the rotation of the globe up or down by stabilizing the muscle's position on the eye. Three patients with Duane's retraction syndrome demonstrated abnormal vertical movement on adduction and underwent a Y-splitting on the lateral rectus. In all patients, marked decrease in the up-and downshoot is noted after surgery.

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Effect of lateral restraint on the buckling behaviour of plates under non-uniform edge compression

  • Bedair, Osama K.
    • Structural Engineering and Mechanics
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    • v.5 no.1
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    • pp.85-104
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    • 1997
  • The paper investigates the influence of lateral restraint on the buckling behaviour of plate under non-uniform compression. The unloaded edges are assumed to be partially restrained against translation in the plane of the plate and the distributions of the resulting forces acting on the plate are shown. The stability analysis is done numerically using the Galerkin method and various strategies the economize the numerical implementation are presented. Results are obtained showing the variation of the buckling load, from free edge translation to fully restrained, with unloaded edges simply supported, clamped and partially restrained against rotation for various plate aspect ratios and stress gradient coefficients. An apparent decrease in the buckling load is observed due to these destabilizing forces acting in the plate and changes in the buckling modes are observed by increasing the intensity of the lateral restraint. A comparison is made between the budding loads predicted from various formulas in stability standards based on free edge translation and the values derived from the present investigation. A difference of about 34% in the predicted buckling load and different buckling mode were found.

The Versatility of Cheek Rotation Flaps

  • Kim, Kyung Pil;Sim, Ho Seup;Choi, Jun Ho;Lee, Sam Yong;Lee, Do Hun;Kim, Seong Hwan;Kim, Hong Min;Hwang, Jae Ha;Kim, Kwang Seog
    • Archives of Craniofacial Surgery
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    • v.17 no.4
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    • pp.190-197
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    • 2016
  • Background: The cheek rotation flap has sufficient blood flow and large flap size and it is also flexible and easy to manipulate. It has been used for reconstruction of defects on cheek, lower eyelid, or medial and lateral canthus. For the large defects on central nose, paramedian forehead flap has been used, but patients were reluctant despite the remaining same skin tone on damaged area because of remaining scars on forehead. However, the cheek flap is cosmetically superior as it uses the adjacent large flap. Thus, the study aims to demonstrate its versatility with clinical practices. Methods: This is retrospective case study on 38 patients who removed facial masses and reconstructed by the cheek rotation flap from 2008 to 2015. It consists of defects on cheek (16), lower eyelid (12), nose (3), medial canthus (3), lateral canthus (2), and preauricle (2). Buccal mucosa was used for the reconstruction of eyelid conjunctiva, and skin graft was processed for nasal mucosa reconstruction. Results: The average defect size was 6.4cm2, and the average flap size was 47.3cm2. Every flap recovered without complications such as abnormal slant, entropion or ectropion in lower eyelid, but revision surgery required in three cases of nasal side wall reconstruction due to the occurrence of dog ear on nasolabial sulcus. Conclusion: The cheek rotation flap can be applicable instead of paramedian forehead flap for the large nasal sidewall defect reconstruction as well as former medial and lateral canthal defect reconstruction.

Use of Flattening Filter Free Photon Beams for Off-axis Targets in Conformal Arc Stereotactic Body Radiation Therapy

  • Smith, Ashley;Kim, Siyong;Serago, Christopher;Hintenlang, Kathleen;Ko, Stephen;Vallow, Laura;Peterson, Jennifer;Hintenlang, David;Heckman, Michael;Buskirk, Steven
    • Progress in Medical Physics
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    • v.25 no.4
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    • pp.288-297
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    • 2014
  • Dynamic conformal arc therapy (DCAT) and flattening-filter-free (FFF) beams are commonly adopted for efficient conformal dose delivery in stereotactic body radiation therapy (SBRT). Off-axis geometry (OAG) may be necessary to obtain full gantry rotation without collision, which has been shown to be beneficial for peripheral targets using flattened beams. In this study dose distributions in OAG using FFF were evaluated and the effect of mechanical rotation induced uncertainty was investigated. For the lateral target, OAG evaluation, sphere targets (2, 4, and 6 cm diameter) were placed at three locations (central axis, 3 cm off-axis, and 6 cm off-axis) in a representative patient CT set. For each target, DCAT plans under the same objective were obtained for 6X, 6FFF, 10X, and 10FFF. The parameters used to evaluate the quality of the plans were homogeneity index (HI), conformality indices (CI), and beam on time (BOT). Next, the mechanical rotation induced uncertainty was evaluated using five SBRT patient plans that were randomly selected from a group of patients with laterally located tumors. For each of the five cases, a plan was generated using OAG and CAG with the same prescription and coverage. Each was replanned to account for one degree collimator/couch rotation errors during delivery. Prescription isodose coverage, CI, and lung dose were evaluated. HI and CI values for the lateral target, OAG evaluation were similar for flattened and unflattened beams; however, 6FFF provided slightly better values than 10FFF in OAG. For all plans the HI and CI were acceptable with the maximum difference between flattened and unflattend beams being 0.1. FFF beams showed better conformality than flattened beams for low doses and small targets. Variation due to rotational error for isodose coverage, CI, and lung dose was generally smaller for CAG compared to OAG, with some of these comparisons reaching statistical significance. However, the variations in dose distributions for either treatment technique were small and may not be clinically significant. FFF beams showed acceptable dose distributions in OAG. Although 10FFF provides more dramatic BOT reduction, it generally provides less favorable dosimetric indices compared to 6FFF in OAG. Mechanical uncertainty in collimator and couch rotation had an increased effect for OAG compared to CAG; however, the variations in dose distributions for either treatment technique were minimal.

ARATIVE STUDY OF MAXILLARY SUPERIMPOSITION METHODS ON A LATERAL R NTGENOGRAPHIC CEPHALOMETRY (측모두부방사선사진을 이용한 상악 중첩 방법의 비교연구)

  • Jean, Young-Yim
    • Journal of the korean academy of Pediatric Dentistry
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    • v.25 no.1
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    • pp.197-208
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    • 1998
  • This study was carried out to compare the amount of the maxillary bone remodeling and tooth displacement in each three maxillary superimposition methods, Ricketts, Best-fit, Structural method. Forty cases of the lateral cephalometric radiographs from 27 boys and 13 girls who had been treated to correct anterior cross-bite were selected for the study. The initial radiographs were taken at about 8-year-old and the second radiographs were taken in about 3.3 years later. Followings were the results: 1. With the Structural method, backward movement was shown in PNS, while forward movement was observed in ANS and point A. With the Ricketts method, however, all structures were shown significant backward movement comparing with Structural method(P<0.05). With the Best-fit method, the amount of horizontal movement was similar to that of the Structural method(P>0.05). 2. The palate seemed to be moved downward with Structural method, but there was no measured downward remodeling on nasal floor with Ricketts and Best-fit method(P<0.05). 3. Comparing with Structural method, Ricketts and Best-fit method significantly underestimated the eruption of the teeth by 20% to 30% (P<0.05). 4. The Structural method showed the anteroinferior rotation (43%) and posteroinferior rotation(57%) of the palatal plane, while the Best-fit method showed mostly anterosuperior rotation(87%), but no change was found in the Ricketts method. 5. With the Structural method, there was a statistically significant correlation between the amount of the rotation of the palatal plane and that of N-S line(r=0.86). 6. The measured angles of the long axis of the incisors and molars showed no significant difference in each 3 methods(P>0.05).

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