• Journal of Biomedical Engineering Research
• /
• v.24 no.6 s.81
• /
• pp.495-500
• /
• 2003

The purpose of this investigation was to study the kinematics of joints between the foot segments based on computer graphic model during the stance? phase of walking. In the model, all joints were assumed to act as monocentric. single degree of freedom hinge joints. The motion of foot was captured by a video collection system using four cameras. The model fitted in an individual subject was simulated with this motion data. The range of motion of the first tarsometatarsal joint was $-8^{\circ}\;\~\;-13^{\circ}$, and the first metatarsophanlangeal joint was $-13^{\circ}\;\~\;-48^{\circ}$. The kinematic data of tarsometatarsal joint and metatarsophanlangeal joint were similar to the previous data. Therefore, our method based on the graphical computer model is considered useful.

• Journal of Biomedical Engineering Research
• /
• v.22 no.1
• /
• pp.69-80
• /
• 2001

본 연구에서는 환자의 골다공증 유무에 따른 내고정 장치 시술 직후 및 융합 후의 안정성을 평가하기 위해 다양한 하중 모드에서 C5-C6 운동분절의 생체역학적 거동을 분석하였다. 이러한 목적으로 먼저, C5-C6 경추부의 유한요소 모델을 구현하여 검증하였다. 모델의 결과는 기존 실험치와 유사하여 신뢰성이 부여되었다. 검증된 모델은 Smith-Robinson 방식으로 골이식물을 삽입한 후 전방 내고정 장치를 적용한 시술 상황을 재현하기 위해 수정되었다. 수정된 모델은 두 종류로 구현되었다. (1) 첫 번째 모델에서는, 시술 직후의 상황을 재현하기 위해 골이식물과 종판의 경계면에 접촉요소를 사용하였다. (2)두 번째 모델에서는 완전히 융합된 상황을 나타내기 위해 골이식물을 종판에 고정하였다. 골다공증의 효과를 예측하기 위하여 두 모델의 해면골에 대한 탄성계수를 변화시켰다(정상: 100MPa, 골다공증: 40MPa). 각 모델의 C5 주체의 상위면에 73.6N의 압축 하중을 가한 후에 108Nm의 굴곡/신전, 굽힘, 비틀림 하중을 가하였으며, C6 추체의 하단면은 모든 방향에 대하여 구속하였다. 전체적인 결과에 있어서 상대적 회전운동, 미끄럼운동, 골이식물 내에서의 von Mises 응력의 경우 정상 모델에 비해 골다공증 모델에서 증가함을 보였으며, 특히 시술 직후의 모델에서 비틀림 하중이 가해진 경우, 상대적 회전운동 및 미끄럼 운동이 가장 높게 예측되었다. 이는 골다공증환자에게 전방 내고정 장치를 시술한 경우 골이식물의 파단 및 유합의 실패가 비틀림 하중에서 발생할 수 있음을 나타낸다. 해면골의 von Mises 응력은 시술 직후에 골다공증 모델의 모든 하중 모드에서, 유합 후에는 굽힘 하중 외의 모든 하중에서 ultimate strength를 초과하는 것으로 나타나 골다공증 환자에게 screw의 해리가 발생할 가능성이 높은 것으로 예측되었다. 따라서 골다공증 환자에게 과도한 운동이 발생하지 않도록 하기 위해서 시술 후 세심한 주의와 halo 같은 견고한 정형술이 필요할 것으로 사료된다.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.3
• /
• pp.353-359
• /
• 2000

Objective : The fracture on the frontal bone in head-injured patients may be commonly encountered in the clinical situations. Biomechanical studies demonstrate that the anterior wall of the frontal sinus is intermediate in its ability to resist fracture on direct impact. If the frontal sinus is large and the anterior table is able to disperse the force of the impact over a greater area, the posterior table and intracranial contents usually can be spared. We analyzed the clinical features of the patients who presented with frontal skull fracture due to frontal blows. Patients and Methods : From January, 1992 to December, 1997, 172 patients with frontal skull fracture were selected among 1911 patients with head injury who were admitted to department of neurosurgery. Clinical records and radiological studies of all patients were reviewed and evaluated retrospectively. Results : The neurobehavioral changes was seen in 34 cases(19.8%) and showed statistical significances in case of facial bone fractures, acute subdural hematoma(SDH), and positive frontal lobe releasing sign(p<0.05). The good glasgow outcome score group(GOS, good recovery & moderate disability) at discharge was revealed in 77.3% of total patient population. The poor GOS group(severe disability & vegetative state & death) at discharge was revealed in 22.7%. The poor GOS group at discharge have statistical significances with acute epidural hematoma(EDH), traumatic intraventricular hemorrhage(t-IVH), traumatic intracranial lesion, poor initial glasgow coma scale(GCS) scores & Revised Trauma Score(RTS)(p<0.05). Conclusion : Because of their anatomical relationships and neurobehavioral patterns due to vulnerability of the frontal lobe, the frontal injury should be considered as complicated facial injuries. Therefore, these patients are more likely to have a cosmetic or neuropsychiatric problems.

• Restorative Dentistry and Endodontics
• /
• v.39 no.4
• /
• pp.265-269
• /
• 2014

Objectives: To evaluate the effect of different ultrasonic tip designs on intraradicular post removal. Materials and Methods: The crowns of forty human canine teeth were removed, and after biomechanical preparation and filling, the roots were embedded in acrylic resin blocks. The post spaces were made, and root canal molding was performed with self-cured acrylic resin. After casting (Cu-Al), the posts were cemented with zinc phosphate cement. The specimens were randomly separated into 4 groups (n = 10), as follows: G1 - no ultrasonic vibration (control); G2 - ultrasonic vibration using an elongated cylindrical-shaped and active rounded tip; G3 - ultrasonic vibration with a flattened convex and linear active tip; G4 - ultrasonic vibration with active semicircular tapered tip. Ultrasonic vibration was applied for 15 seconds on each post surface and tensile test was performed in a Universal Testing Machine (Instron 4444 - 1 mm/min). Results: G4 presented the highest mean values, however, with no statistically significant difference in comparison to G3 (p > 0.05). G2 presented the lowest mean values with statistically significant difference to G3 and G4 (p < 0.05). Conclusions: Ultrasonic vibration with elongated cylindrical-shaped and active rounded tip was most effective in reducing force required for intraradicular post removal.

• Restorative Dentistry and Endodontics
• /
• v.38 no.3
• /
• pp.167-171
• /
• 2013

Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer) and PathFile #13, #16 and #19 (Dentsply Maillefer) up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH) was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH) and AH Plus sealer (Dentsply Maillefer), using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods.

• Journal of Korean Neurosurgical Society
• /
• v.53 no.6
• /
• pp.356-369
• /
• 2013

Objective : We performed a retrospective analysis of medical records and radiographic images of patients who never underwent spinal treatment including diagnosis. The objective of this study is to explain the biomechanical and physiologic characteristics of cervical alignment related to thoracic inlet angle including T1 slope changes in each individual. Methods : We reviewed the cervical CT radiographs of 80 patients who visited ENT outpatient clinic without any symptom, diagnosis and treatment of cervical spine from January 2011 to September 2012. All targeted people were randomized without any prejudice. We assessed the data-T1 slope, Cobb's angle C2-7, neck tilt, sagittal vertical axis (SVA) C2-7 and thoracic inlet angle by the CT radiographs. Results : The relationships between each value were analyzed and we concluded that Cobb's angle C2-7 gets higher as the T1 slope gets higher, while the SVA C2-7 value decreases. Conclusion : We propose that the T1 slope is background information in deciding how much angle can be made in the cervical spinal angle of surgical lordotic curvature, especially severe cervical deformity.

• Journal of Ginseng Research
• /
• v.37 no.4
• /
• pp.435-441
• /
• 2013

This study investigated the effects of Korean Red Ginseng (KRG) on radiation-induced bone loss in C3H/HeN mice. C3H/HeN mice were divided into sham and irradiation (3 Gy, gamma-ray) groups. The irradiated mice were treated for 12 wk with vehicle, KRG (per os, p.o.) or KRG (intraperitoneal). Serum alkaline phosphatase (ALP), tartrate-resistant acid phosphatase, estradiol level, and biomechanical properties were measured. Tibiae were analyzed using micro-computed tomography. Treatment of KRG (p.o., 250 mg/kg of body weight/d) significantly preserved trabecular bone volume, trabecular number, structure model index, and bone mineral density of proximal tibia metaphysic, but did not alter the uterus weight of the mice. Serum ALP level was slightly reduced by KRG treatment. However, grip strength, mechanical property, and cortical bone architecture did not differ among the experimental groups. The results indicate that KRG can prevent radiation-induced bone loss in mice.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.4
• /
• pp.415-421
• /
• 2021

The biomechanical prognosis of conventional removable partial denture is questionable in case of patient with few remaining teeth or periodontally compromised teeth. In this case, hybrid telescopic double crown RPD may be a successful treatment alternative. Hybrid telescopic double crown RPD has following advantages over conventional RPD: secondary splinting effect between abutments, more vertical stress direction and more convenient in repairing the denture after extraction of abutment tooth. In this clinical case, patient had deep overbite in anteriors and partially edentulous. The maxilla was restored with hybrid telescopic double crown RPD and the mandible was restored with implants and fixed prostheses. Long-term follow-up and supportive periodontal treatment were performed, and satisfactory results were achieved in terms of function and aesthetics.

• Journal of The Korean Society of Integrative Medicine
• /
• v.9 no.2
• /
• pp.63-73
• /
• 2021

Purpose : Selective functional movement assessment(SFMA) is a movement-based assessment tool designed for clinicians to diagnose and treat pain and functional physical problems. This concept is used for assistance in occupations related to movement, including clinical medical personnel, such as physical therapists, physical education instructors, and athlete coaches. Although this concept is widely used by clinicians, research and scientific proofs are relatively insufficient. This study aimed to review the literature on the understanding, reliability and effectiveness of SFMA, and to consider its role in the future of rehabilitation. Methods : In this review, a total of nine articles were selected according to the eligibility criteria of three major thesis topics. The main topics covered in the literature are reliability and effectiveness of clinical use of SFMA. To gather research articles, we searched official term 'Selective Functional Movement Assessment'. Among the searched 60 studies, nine were mentioned in this study that contained overlapping information and matched our desired topic. We reviewed four reliability analyses, four case reports, and one experimental study. Results : Reliability has an intermediate degree between high raters and within raters. The validity of the SFMA system is influenced by a combination of experience and logic; hence, further improvement is needed. Therefore, if the intervention was effective based on the diagnosis result, then biomechanical evidence is necessary to further support the claim. Conclusion : In future research, to use SFMA as a diagnostic tool with high accuracy, it is necessary to improve the reliability of the main problem through breakout, support for guidelines and validity and efficiency.

• Physical Therapy Korea
• /
• v.26 no.3
• /
• pp.42-56
• /
• 2019

Background: Individuals with mechanical neck pain show biomechanical and neurophysiological changes, including cervical spine muscle weakness. As a result of deep muscle weakness, it causes stability disability and reduced upper thoracic spine mobility, which finally leads to functional movement restriction such as limited range of motion and dysfunction. Recent studies have shown that thoracic spine manipulation and mobilization could reduce symptoms of mechanical neck pain in patients. Objects: The purpose of this study was to investigate the effects of thoracic mobility exercise on cervicothoracic function, posture feature, and pain intensity in individuals with mechanical neck pain. Methods: The study subjects were 26 persons who were randomly assigned to the experimental (with thoracic mobility exercise) and control groups (without thoracic mobility exercise), with 13 subjects in each group. The cervicothoracic function (neck functional disability level and cervicothoracic range of motion), posture feature, and pain rating (using a quadrupled visual analogue scale [QVAS]) were measured before, after 3 weeks, and after 6 weeks. Results: Statistically significant group-by-time interactions were found with repeated analyses of variance for the Korean neck disability index (KNDI), all cervical range of motion (CROM), all thoracic range of motion (TROM), cranial rotation angle, sagittal shoulder posture (SSP), and QVAS (p<.05). All groups showed significant improvements from all times in all the evaluated methods. The KNDI, CROM, TROM of left rotation, and SSP in the experimental group showed significant improvements after 3 weeks, and the TROM of the right rotation and QVAS in the experimental group showed significant improvements after 6 weeks when compared with the control group. Conclusion: Thoracic mobility exercise during 6 weeks might be effective intervention to improve the functional level, posture feature, and QVAS pain rating for managing individuals with mechanical neck pain.