• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.95-101
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• 2014

The purpose of this study was to investigate the training and detraining effects of a 8-week water exercise on lower extremities coordination during obstacle gait in the female elderly. Eight elderly participants (age: $76.58{\pm}4.97$ yrs, height: $148.88{\pm}7.19$ cm, body mass: $56.62{\pm}6.82$ kg, and leg length: $82.36{\pm}2.98$ cm), who stayed at the Seoul K welfare center, were recruited for this study. All participants had no history of orthopedic abnormality within the past 1 year and completed the aquatic exercise program which lasted for 8 weeks. To identify the training and detraining effect of 8 weeks of water exercise, a 3-D motion analysis with 7 infrared cameras and one force plate sampling frequency set at 100 Hz and 1,000 Hz, respectively, was performed. A two-way ANOVA was performed to find training and detraining effects among diferent obstacle heights. In this study significant level was set at .05. Significant training effects of LTS (lead foot thigh and shank) coordination in all obstacle height were found (p<.05). It is also found that the training effect of LTS remained 37%, 58%, and 25% in obstacle height of 30%, 40%, and 50%, respectively. Lead foot showed the greater detraining effect of coordination compared with trail foot, and SF (shank and foot) coordination revealed better detraining effects of coordination compare with TS (thigh and shank) in both feet. Based on the findings, a 8 week water exercise give an positive effects to the elderly in terms of segment cooperation which potentially helps reducing their accident falls. The magnitude of detraining may also help the elderly to find the retraining moment.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.69-77
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• 2021

Objective : Classification systems for cervical ossification of the posterior longitudinal ligament (OPLL) have traditionally focused on the morphological characteristics of ossification. Although the classification describes many clinical features associated with the shape of the ossification, including the concept of spondylosis seems necessary because of the similarity in age distribution. Methods : Patients diagnosed with OPLL who presented with increase signal intensity (ISI) on magnetic resonance imaging were surgically treated in our department. The patients were divided into two groups (pure versus degenerative) according to the presence of disc degeneration. Results : Of 141 patients enrolled in this study, more than half (61%) were classified into the degenerative group. The pure group showed a profound male predominance, early presentation of myelopathy, and a different predilection for ISI compared to the degenerative group. The mean canal compromise ratio (CC) of the ISI was 47% in the degenerative group versus 61% in the pure group (p<0.0000). On the contrary, the global and segment motions were significantly larger in the degenerative group (p<0.0000 and p=0.003, respectively). The canal diameters and global angles did not differ between groups. Conclusion : Classifying cervical OPLL based on the presence of combined disc degeneration is beneficial for understanding the disorder's behavior. CC appears to be the main factor in the development of myelopathy in the pure group, whereas additional dynamic factors appear to affect its development in the degenerative group.

• Korean Journal of Applied Biomechanics
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• v.32 no.3
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• pp.87-93
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• 2022

Objective: The purpose of this research was to investigate the age-related changes in whole-body motor variability during sit-to-stand (STS) task. It has been reported that children perform motor tasks less accurately with greater variability as compared to adults. However, it is still unknown how they utilize the abundant degrees of freedom and accomplish voluntary actions. Uncontrolled manifold (UCM) analysis has been used to partition motor variabilities into two independent variability components, task-relevant variability (V_ORT) and task-irrelevant variability (V_UCM). We investigated what differences exist between children and adults with respect to these two motor variability components in relation to motor development stages. Method: Ten 6-year-old children (height: 116.2 ± 4.3 cm, weight: 23.1 ± 3.9 kg, motor development assessment percentile score: 77.5 ± 18.6%), ten 10-year-old children (height: 138.7 ± 7.2 cm, weight: 35.8 ± 10.3 kg, motor development assessment percentile score: 73.9 ± 12.7%), and ten young adults (age: 23 ± 1.6 year-old, height: 164.3 ± 11.4 cm, weight: 60.8 ± 12.0 kg) participated in this study. Each participant performed STS ten times, and a motion capture system was used to capture the whole-body kinematics. Each segment centers of mass and the whole-body center of mass were calculated, and UCM analysis was used to quantify motor variabilities, V_ORT and V_UCM. One-way ANOVA was used for statistical analysis. Results: We found that children produced more motor variabilities in V_ORT and V_UCM in all three dimensions, anterior-posterior, medial-lateral, and vertical. As age increased, both, V_ORT and V_UCM significantly decreased (p<.05). Conclusion: The greater V_ORT found in children compared to adults indicates that the repeatability over repetitions improves through development, while the greater V_UCM found in children suggests that children better utilize the abundant degrees of freedom during STS compared to adults.

• Journal of Korean Neurosurgical Society
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• v.46 no.6
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• pp.532-537
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• 2009

Objective : Recently, motion preservation has come to the forefront of emerging technologies in spine surgery. This is the important background information of the emergence of cervical arthroplasty as an alternative to arthrodesis that offers the promise of restoring normal spinal movement and reduces a kinematic strain on adjacent segments. The study was designed to evaluate early surgical outcome and radiological effects of $Bryan^{(R)}$ cervical disc prosthesis. Methods : The authors retrospectively reviewed radiographic and clinical outcomes in 52 patients who received the $Bryan^{(R)}$ Cervical Disc prosthesis, for whom follow-up data were available. Static and dynamic radiographs were measured by computer to determine the angles formed by the endplates of the natural disc preoperatively, those formed by the shells of the implanted prosthesis, the angle of functional spine unit (FSU), and the C2-7 Cobb angle. The range of motion (ROM) was also determined radiographically, whereas clinical outcomes were assessed using Odom's criteria, visual analogue pain scale (VAS) and neck disability index (NDI). Results : A total of 71 $Bryan^{(R)}$ disc were placed in 52 patients. A single-level procedure was performed in 36 patients, a two-level procedure in 13 patients, and a three-level procedure in 3. Radiographic and clinical assessments were made preoperatively. Mean follow-up duration was 29.2 months, ranging from 6 to 36 months. All of the patients were satisfied with the surgical results by Odom's criteria, and showed significant improvement by VAS and NDI score (p < 0.05). The postoperative ROM of the implanted level was preserved without significant difference from preoperative ROM of the operated level (p < 0.05). 97% of patients with a preoperative lordotic sagittal orientation of the FSU were able to maintain lordosis. The overall sagittal alignment of the cervical spine was preserved in 88.5% of cases at the final follow up. Interestingly, preoperatively kyphotic FSU resulted in lordotic FSU in 70% of patients during the late follow up, and preoperatively kyphotic overall cervical alignment resulted in lordosis in 66.6% of the patients postoperatively. Conclusion : Arthroplasty using the $Bryan^{(R)}$ disc seemed to be safe and provided encouraging clinical and radiologic outcome in our study. Although the early results are promising, this is a relatively new approach, therefore long-term follow up studies are required to prove its efficacy and its ability to prevent adjacent segment disease.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.6
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• pp.526-534
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• 2001

Purpose : The objective of this study is to ascertain whether the positive exists among the frenum length, the tongue movement and the speech and to present the normal range of tongue movement and guidelines for the choice of surgery, observation if necessary. Materials and Methods : 180 patients were evaluated. We divided 180 patients into 6 group by age. Each group was separated as follows; the age of 2.5-4, 5-6, 7-9, 10-12, 16-18. We measured the frenal length, the range of tongue motion and evaluated the speech so that we really questioned about the positive relationship between the tongue-tie and speech. We let the patient exercise the protrusive both(right, left) laterotrusive superior movement of the tongue. During these movements, we measured the distance between the vermilion border and the tongue tip. We also measured the distance from the tongue tip to the point contacting the upper lip with dorsum of the tongue during the maximal protrusive movement of the tongue. Three linear measurement of the anterior, inferior segment of the tongue including the lingual frenum, are made. These measurements are as follows: 1. Distance A. Free anterior portion of the tongue from the point of frenular insertion to the tongue tip. 2. Distance B. The distance from the initiating point of the lingual frenum to the point connecting the two sublingual carundcles to the lingual frenum perpendicularly. 3. Distance C. The distance from the point contacting the line crossing the sublingual caruncles with the lingual frenum to the terminating point of the lingual frenum. We transform three linear measures into a statistical ratio, A/(A-B+C), representing the length of the free portion of the tongue compared with the total sublingual dimensions. In addition, we assessed the speech through Picture Consonant Articulation Test(PCAT) and tried to find out the relationship between the length of the lingual frenum and speech. Conclusion : As people are born, they have small and restricted tongue. As people grow old, tongue motions are more liberate, and unrestricted and they can speak so freely. Therefore we suggest that until age 5, oral and maxillofacial surgeons postpone the surgery if not urgent, evaluate the maximal lingual motions and PCAT according to this article and observe their changes.

• Journal of Korean Neurosurgical Society
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• v.43 no.5
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• pp.221-226
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• 2008

Objective : The aim of the present study was to assess the safety and efficacy of the dynamic stabilization system in the treatment of degenerative spinal diseases. Methods : The study population included 20 consecutive patients (13 females, 7 males) with a mean age of $61{\pm}6.98$ years (range 46-70) who underwent decompression and dynamic stabilization with the Dynesys system between January 2005 and August 2006. The diagnoses included spinal stenosis with degenerative spondylolisthesis (9/20, 45%), degenerative spinal stenosis (5/20, 25%), adjacent segmental disease after fusion (3/20, 15%), spinal stenosis with degenerative scoliosis (2/20, 10%) and recurrent intervertebral lumbar disc herniation (1/20, 5%). All of the patients completed the visual analogue scale (VAS) and the Korean version of the Oswestry Disability Index (ODI). The following radiologic parameters were measured in all patients : global lordotic angles and segmental lordotic angles (stabilized segments, above and below adjacent segments). The range of motion (ROM) was then calculated. Results : The mean follow-up period was $27.25{\pm}5.16$ months (range 16-35 months), and 19 patients (95%) were available for follow-up. One patient had to have the implant removed. There were 30 stabilized segments in 19 patients. Monosegmental stabilization was performed in 9 patients (47.3%), 9 patients (47.3%) underwent two segmental stabilizations and one patient (5.3%) underwent three segmental stabilizations. The most frequently treated segment was L4-5 (15/30, 50%), followed by L3-4 (12/30, 40%) and L5-S1 (3/30, 10%). The VAS decreased from $8.55{\pm}1.21$ to $2.20{\pm}1.70$ (p<0.001), and the patients' mean score on the Korean version of the ODI improved from $79.58%{\pm}15.93%$ to $22.17%{\pm}17.24%$ (p<0.001). No statistically significant changes were seen on the ROM at the stabilized segments (p=0.502) and adjacent segments (above segments, p=0.453, below segments, p=0.062). There were no patients with implant failure. Conclusion : The results of this study show that the Dynesys system could preserve the motion of stabilized segments and provide clinical improvement in patients with degenerative spinal stenosis with instability. Thus, dynamic stabilization systems with adequate decompression may be an alternative surgical option to conventional fusion in selected patients.

• Journal of Chest Surgery
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• v.8 no.1
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• pp.37-44
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• 1975

Authors have reviewed the records of seven patients of multiple rib fractures with severe flail chest who were admitted to Hanyang University Hospital during the 3 years period from 1972 through 1975. Of the seven patients studied, automobile accidents led to the injuries in 4 cases, two patients were injured in fall from a tree and on the ox-heading. All who had a blunt trauma without any open wound on the chest. The numbers of the fractured ribs accounted for 6 to 9 of the ribs including double fractures from 3 to 5 ribs. The left side fractures occurred in the 6 patients and in the right only one patient. Thus the flail segment was more often located in the left antero-lateral position than in the right lateral position [the ratio was 6:1].. All cases had associated injuries. The injuries and multiple fractures were the most common associated injuries occurring in four and five of the patients respectively. The patients were classified as having associated head injuries when they were admitted in comatose or semicomatose state. When a major degree of instability of the thoracic cage exists, adequate respiratory change is not possible. For this reason the tracheostomy was performed in five patients in an acutely injured patient with flail chest only after an endotracheal tube has been inserted or after an endotracheal suction. All patients had secondary complications in the pleural cavity, such as hemothorax or hemopneumothorax with or without intrapulmonary hemorrhage and subcutaneous emphysema. Therefore, closed thoracostomy was performed in five patients in the emergency room. The thoracotomy was required in four patients: immediate operation without closed thoracostomy was performed in two patients and the thoracotomy was indicated in two patients after closed thoracostomy, because of increasing intrathoracic hemorrhage. As to the fixation of the flail segments, authors employed two techniques; one was towel clip traction of the flail segments and the other was intramedullary insertion of Kirschner`s wire in to the double fractured rib fragments for the fixation of the flail segments [Kirschner`s wire fixation]. Because` of an different results in the course of treatment between two techniques, data from patients with towel clip traction was compared with those from patients with thoracotomy and Kirschner`s wire fixation of the flail segments. Of the three patients with towel clip traction, two patients required bronchoscopic toilet due to lung atelectasis which developed because of inadequate motion of thoracic cage and poor expectoration. This was in contrast to the four patients with thoracotomy and Kirschner`s wire fixation, who didn`t these complication because of adequate motion of the thoracic cage and subsequent good expectoration.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.6
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• pp.471-476
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• 2016

In this paper, recognition system for continuous human action is explained by using motion history image and histogram of oriented gradient with spotter model based on depth information, and the spotter model which performs action spotting is proposed to improve recognition performance in the recognition system. The steps of this system are composed of pre-processing, human action and spotter modeling and continuous human action recognition. In pre-processing process, Depth-MHI-HOG is used to extract space-time template-based features after image segmentation, and human action and spotter modeling generates sequence by using the extracted feature. Human action models which are appropriate for each of defined action and a proposed spotter model are created by using these generated sequences and the hidden markov model. Continuous human action recognition performs action spotting to segment meaningful action and meaningless action by the spotter model in continuous action sequence, and continuously recognizes human action comparing probability values of model for meaningful action sequence. Experimental results demonstrate that the proposed model efficiently improves recognition performance in continuous action recognition system.

• Elastomers and Composites
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• v.40 no.2
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• pp.136-142
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• 2005

Liquid crystalline poly(allylsulfone) networks having $SO_2$ in a main chain and mesogens in a side chain were synthesized and their gas permeability and permselectivity were determined. The monomer II having two allyl groups on the each end group was able to form polymer networks by polymerization reaction, while the monomer I having only one allyl group was not. Molecular motion of the poly(allylsulfone) networks were retarded with increasing the cross-linking density, and the segmental motion of networks was developed enough to show isotropic phase transition. Gas permeabilities of poly(II-5 $01/I-OCH_3$ 99) were 2.58 baller for $O_2$ and 18.4 barrer for $H_2$. It means that hydrogen gas are 7 times more permeable than oxygen. Its permselectivities were high as 23.9 for ${\alpha}(H_2/N_2)$. The permselectivity was increased with increasing the cross-linking density. For example, ${\alpha}(H_2/N_2)$ was 36.8 in poly(II-5 $10/I-OCH_3$ 90), which was shown to be the highest value among these poly(allylsulfone) networks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.36-44
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• 2019

Swallowing impairment is a frequent complication following stroke. The characteristics of swallowing impairment with stork patient can facilitate identification of individuals at risk of dysphagia would be of great helpful. The present study examined oropharyngeal swallowing impairment with subacute stroke patients using the Modified Barium Swallowing Impairment Profile(MBSImP). The 49 consecutive patients with the supratentorial stroke met inclusion criteria for the present study. A retrospective review was performed of patients who underwent the videofluoroscopic swallowing study(VFSS). Of Stroke patients, 95.9% exhibited abnormal function of lip closure. 98% and 57.1 % shown abnormal tongue function and lingual motion, respectively. Oral residue was present in 51% and delayed pharyngeal response was present in 89.9%. In addition, abnormal laryngeal and hyoid excursion was seen in 42.9% and 87.8%, respectively. Abnormal function of soft palate elevation was present in 18.4% and abnormal epiglottic movement was seen in 4.1%. 30.6% of 30.6% of these patients exhibited abnormal laryngeal closure. All of the stroke patients(100%) in this study exhibited abnormal pharyngeal stripping wave and pharyngoesophageal segment opening. Abnormal tongue base retraction and oral reside were present 91.8%, respectively. The results suggest that stroke patient is more likely to exhibit reduced swallowing functions including lip closure, tongue control, initiation of pharyngeal swallow, anterior hyoid motion, tongue base retraction, pharyngeal residue and pharyngoesophageal contraction. Therefore, these data could provide valid and precise information regarding physiological evidence to delineate symptoms of dysphagia in this stroke cohort. Future studies should explore the bolus effect in the swallowing impairment.