• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.45-50
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• 2007

Purpose: To evaluate the short-term clinical outcomes of total ankle arthroplasty for the post-traumatic osteoarthritis. Materials and Methods: Fourteen patients who had undergone total ankle arthroplasty from February 2005 to June 2006 were reviewed. Eleven patients were male and three patients were female. The mean age was 52.8 years (range, 33 to 69 years). The mean follow-up duration was 15.9 months (range, 12 to 24 months). Primary injuries were pilon fractures in eight cases, malleolar fractures in three, ankle syndesmotic injury in one, talus fracture and dislocation in one, and distal tibial physeal injury in one. Visual analogue scale (VAS), Range of motion (ROM), American Orthopaedic Foot and Ankle Society (AOFAS) score and complications were evaluated. Results: The mean VAS improved from 8.6 preoperatively to 2.6 at last follow-up. The mean ROM improved from 24.6 degrees preoperatively to 33.1 degrees postoperatively. The mean AOFAS score improved from 44.5 points preoperatively to 75.1 points postoperatively. Radiographically, all components were stable, but there were component malpositions in two cases, including one varus malposition of tibial component and one increased anterior translation of talar component. Complications were deep infection in one case, intraoperative malleolar fracture in three, marginal wound necrosis in two, and heterotopic ossification in one. One prosthesis was revised because of deep infection. Conclusion: Total ankle arthroplasty for the post-traumatic osteoarthritis is believed to be an useful method for preservation of the motion, relief of the pain and high satisfaction of patients in short-term results.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.194-201
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• 2004

Optical fibers are indispensable fer optical communication systems that transmit large volumes of data at high speed. But the aligning technology under the sub-micron accuracy is required for the precise axis adjustment and connection. For the purpose of precise alignment of the optical arrays, in this research, we have developed the 12-axis(with 8 automated axis and 4 manual axis) automatic optical fiber alignment system including the image processing-based searching system, the automatic loading system using the robot and the suction toot and the automatic UV bonding system. In order to obtain the sub-micron alignment accuracy, two 4-axis PC-based motion controllers and the two 50nm resolution 6-aixs micro-stage actuated by micro stepping motors are adopted. The fiber aligning procedure consists of two steps. Firstly, the optical wave guide and an input optical array are aligned by the 6-axis input micro-stage with the IR camera. The image processing technique is introduced to reduce primary manual aligning time and result in achieving the 50% decrease of aligning time. Secondly, the IR camera is replaced by the output micro-stage and a wave guide and two optical arrays are aligned simultaneously before the laser power intensity delivered to the optical powermeter reached the threshold value. When the aligning procedure is finished, the wave guide and arrays are W bonded. The automatic loading/unloading system is also introduced and the entire wave guide handing time is reduced significantly compared to the former commercial aligning system.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.31-36
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• 2009

There have been many solar tracking systems developed for the high accuracy in solar tracking. One of the key components of any motion control system is software. LabVIEW offers an ideal combination of flexibility, ease-of-use and well-integration with other I/O pieces for developing solar tracking system. Real-time solar positions which vary with GPS's data are used simultaneously to control the solar tracker by a chain of operating modes between the open and closed loops. This paper introduces a step by step procedure for the fabrication and performance assessment of a precision solar tracking system. The system developed in this study consists of motion controllers, motor drives, step-motors, feedback devices and application. CRD sensors are applied for the solar tracking system which play a primary role in poor conditions for tracking due to a gear backlash and a strong wind. Mini-dish was used as a concentrator for collecting sun light. The solar position data, in terms of azimuth and elevation, sunrise and sunset times was compared with those of KASI(Korea Astronomy & Space Science Institute). The results presented in this paper demonstrate the accuracy of the present system in solar tracking and utilization.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.292-300
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• 2011

Control systems in machinery equipment provide correction signals to motion units in order to reduce or cancel out the mismatches between sensor feedback signals and command or desired values. In this paper, we introduce a simulator for control characteristics of machinery equipment. The purpose of the simulator development is to provide mechanical system designers with the ability to estimate how much dynamic performance can be achieved from their design parameters and selected devices at the designing phase. The simulator has a database for commercial parts, so that the designers can choose appropriate components for servo controllers, motors, motor drives, and guide ways, etc. and then tune governing parameters such as controller gains and friction coefficients. The simulator simulates the closed-loop control system which is built and parameter-tuned by the designer and shows dynamic responses of the control system. The simulator treats the moving table as a 6 degrees-of-freedom rigid body and considers the motion guide blocks stiffness, damping and their locations as well as sensor locations. The simulator has been under development for one and a half years and has a few years to go before the public release. The primary achievements and features will be presented in this paper.

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.381-386
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• 2010

This study examined the changes in the walking pattern during level walking under low illumination conditions. Fourteen male subjects ($22.1{\pm}2.21$ years, $174{\pm}3.74\;cm$, $68.86{\pm}10.81\;kg$) with normal vision and no disabilities were enrolled in this study. All experiments were performed on a level walkway with three conditions: normal walking (preferred & low speed) and walking with low illumination. 3D motion capturing system was used for acquisition and analysis of the walking motion data with a sampling frequency of 120Hz. The walking speed, normalized jerk(NJ) at the center of mass(COM), wrist and heel, knee and elbow joint angle, ratio of the knee joint angle to elbow joint angle and the toe clearance on stance phase were used to compare the differences in walking pattern between the two illumination conditions, The results showed that the walking speed and joint angles decreased in low illumination, whereas the NJ and toe minimum clearance increased. In low illumination, most variables were similar to effects of low speed walking, but toe clearance was different from the effects of low speed. These results can be used as primary data for examining the changes in the level walking pattern of young adults under low illumination. Further study will be needed to compare these results in young adults with those in the elderly.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.33-44
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• 2018

Purpose: The primary purpose of this study was to investigate the effects of cervical stabilization exercise (CSE) on hamstring flexibility in patients with neck pain. A secondary purpose of this study was to investigate the effects of cervical range of motion (CROM) and craniovertebral angle (CVA). Methods: This study was a single-blind, randomized, comparative trial. Twenty patients were allocated into either the cranio-cervical flexion exercise (CCFE) group or the CSE group. Before and after the intervention, we measured straight leg raise (SLR), popliteal angle (PA), CROM, and CVA in the sitting and standing positions. Fisher's exact test, the Mann-Whitney test, and Wilcoxon's signed-rank test were used to analyze our data. Results: Both groups showed significant improvements in the value of SLR, PA, cervical extension, cervical rotation, and CVA in the standing position (both, p<.05) after intervention. However, only the CSE group showed significant improvements in cervical right lateral flexion (z=-2.209; p<.01) and cervical left lateral flexion (z=-2.537; p<.05) after intervention. The CSF group showed more significant improvements in SLR, PA, both cervical lateral flexions, and both cervical rotations than the CCFE group. Conclusions: The results of this study will guide future research in identifying the effectiveness of CSE. In conclusion, it can be inferred that CSE has a positive effect on SLR, PA, CROM, and CVA in the standing position in patients with chronic neck pain.

• Archives of Plastic Surgery
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• v.50 no.1
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• pp.10-16
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• 2023

Background The chest wall defects can be caused by various reasons. In the case of malignant tumor resection of the chest wall, it is essential to reconstruct the chest wall to cover the vital tissue and restore the pulmonary function with prevention of paradoxical motion. With our experience, we analyzed and evaluated the results and complications of the chest wall reconstructions followed by malignant tumor resection. Methods From 2013 to 2022, we reviewed a medical record of patients who received chest reconstruction due to chest wall malignant tumor resection. The following data were retrieved: patients' demographic data, tumor type, type of operation, method of chest wall reconstruction of the soft and skeletal tissue and complications. Results There were seven males and six female patients. The causes of reconstruction were 12 primary tumors and one metastatic carcinoma. The pathological types were seven sarcomas, three invasive breast carcinoma, and three squamous cell carcinomas. The skeletal reconstruction was performed in six patients. The series of the flap were eight pedicled latissimus dorsi (LD) myocutaneous flaps, two pectoralis major myocutaneous flap, two vertical rectus abdominis myocutaneous free flap, and one LD free flap. Among all the cases, only one staged reconstruction and successful reconstruction without flail chest. Most of the complications were atelectasis. Conclusion In the case of accompanying multiple ribs and sternal defect, skeletal reconstruction would need skeletal reconstruction to prevent paradoxical chest wall motion. The flap for soft tissue defect be selected according to defect size and location of chest wall. With our experience, we recommend the reconstruction algorithm for chest wall defect due to malignant tumor resection.

• Journal of Korean Physical Therapy Science
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• v.30 no.1
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• pp.62-71
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• 2023

Background: This study was performed to evaluate the effects of Thermal stimulation combined virtual reality training (TV) on improvement of upper extremity AROM and function in patient with chronic stroke. Design: Two groups pre-post randomized controlled design. Methods: A single-blind, randomized controlled trial was conducted with 30 chronic stroke patients. They were randomly allocated two groups; the TV group (n=15) and Virtual Reality training group (VT) (n=15). The TV group received treatment for 30 min - 15 min of Thermal stimulation, and 15 min of VR training. The VT group received 15 min of VR training. Each group performed 30 minutes a day 3 times a week for 8 weeks. The primary outcome upper extremity AROM and function were measured by a active range of motion test, Manual Function Test (MFT) and Jebsen-Taylor hand function Test (JTT). The upper extremity active range of motion was evaluated using a digital dual inclinometer. MFT and JTT were used to evaluate the hand function. The measurement were performed before and after the 8 weeks intervention period. Results: Both groups demonstrated significant improvement of outcome in muscle strength and upper extremity function during intervention period. TV group revealed significant differences in AROM and upper extremity function as compared to the VT groups (p<.05). Our results showed that TV was more effective on upper extremity AROM and function in patients with chronic stroke. Conclusion: Both groups demonstrated significant improvement of outcome in muscle strength and upper extremity function during intervention period. TV group revealed significant differences in AROM and upper extremity function as compared to the VT groups (p<.05). Our results showed that TV was more effective on upper extremity AROM and function in patients with chronic stroke.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.2
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• pp.29-40
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• 2022

PURPOSE: This study examined the effects of an exercise program for the thoracic spine and scapula rather than the neck, which is the primary site of pain. METHODS: Thirty-two elementary school teachers with a forward head posture (FHP) were assigned randomly to either the experimental group (n = 16) or the control group (n = 16). The experimental group performed scapular stabilization exercise (SSE) and thoracic extension exercise (TEE), and the control group performed cervical self-myofascial release exercise and stretching exercise. The pulmonary functions, pain, craniovertebral angle (CVA), and cervical range of motion (CROM) were measured before the intervention and six weeks after. RESULTS: The within-group comparisons showed that the VAS and CROM (except for extension) in both groups were significantly different before and after the intervention (p < .05). The changes in the maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), forced vital capacity (FVC), forced expiratory volume at 1 sec (FEV1), and CVA were significant only in the experimental group (p < .05). The between-group comparisons showed a significant difference in the FVC, FEV1, VAS, CVA, and left lateral flexion (p < .05). CONCLUSION: The combination of SSE and TEE in the experimental group was more effective in improving the FHP and breathing ability. Moreover, the experimental group and control combination appeared to be effective in reducing pain and improving the CROM. The combination of SSE and TEE, which are exercises that do not target the cervical spine directly, was effective in improving the posture, respiration, neck pain, and CROM in elementary school teachers with FHP.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.3
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• pp.85-99
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• 2023

Background: This study aimed to investigate the effects of a complex manual therapy program on hip and knee pain occurring together with menstrual pain and iliotibial band tightness in a woman with sacroiliac joint dysfunction. Methods: This study was carried out over a period of 3 months by dividing the treatment process into three sequential stages. Intensities of menstrual pain, hip pain, and knee pain, and hip range of motion (ROM) in the participant were assessed at baseline and at the end of each stage, and a modified intervention was applied according to results of assessments after each stage. Results: There was a decrease in the intensity of menstrual pain after the first and third stages of treatment, and there were reductions in the intensities of hip and knee pain after the third stage. Hip ROM was rather decreased after the second stage, but it was increased after the third stage. Conclusion: The findings of this study indicate that treatment of the instability and positional fault of sacroiliac joint can relieve hip and knee pain, improve hip ROM, and alleviate primary dysmenorrhea in patients with sacroiliac joint dysfunction.