• Clinics in Shoulder and Elbow
• /
• 제26권2호
• /
• pp.131-139
• /
• 2023

Background: Massive rotator cuff tears (RCTs) are complicated by muscle atrophy, fibrosis, and intramuscular fatty degeneration, which are associated with postoperative tendon-to-bone healing failure and poor clinical outcomes. We evaluated muscle and enthesis changes in large tears with or without suprascapular nerve (SN) injury in a rat model. Methods: Sixty-two adult Sprague-Dawley rats were divided into SN injury (+) and SN injury (-) groups (n=31 each), comprising tendon (supraspinatus [SSP]/infraspinatus [ISP]) and nerve resection and tendon resection only cases, respectively. Muscle weight measurement, histological evaluation, and biomechanical testing were performed 4, 8, and 12 weeks postoperatively. Ultrastructural analysis with block face imaging was performed 8 weeks postoperatively. Results: SSP/ISP muscles in the SN injury (+) group appeared atrophic, with increased fatty tissue and decreased muscle weight, compared to those in the control and SN injury (-) groups. Immunoreactivity was only positive in the SN injury (+) group. Myofibril arrangement irregularity and mitochondrial swelling severity, along with number of fatty cells, were higher in the SN injury (+) group than in the SN injury (-) group. The bone-tendon junction enthesis was firm in the SN injury (-) group; this was atrophic and thinner in the SN injury (+) group, with decreased cell density and immature fibrocartilage. Mechanically, the tendon-bone insertion was significantly weaker in the SN injury (+) group than in the control and SN injury (+) groups. Conclusions: In clinical settings, SN injury may cause severe fatty changes and inhibition of postoperative tendon healing in large RCTs. Level of evidence: Level Basic research, controlled laboratory study.

• 대한수의학회지
• /
• 제64권2호
• /
• pp.16.1-16.9
• /
• 2024

Autologous pericardial tissues are utilized in veterinary cardiovascular surgeries due to their accessibility and effectiveness. To enhance handling and biomechanical properties, glutaraldehyde (GA) fixation is applied. However, GA fixation can induce calcification, leading to tissue failure. This study aimed to establish an optimal rapid anti-calcification protocol by integrating ethanol treatment with the proven effective GA concentration and fixation time, facilitating application from collection to utilization. Pericardia were fixed with 0.625% GA for 20 min and subjected to ethanol treatment for 0 (group A, control), 20 (group B), and 30 minutes (group C). The treated tissues underwent mechanical test and were implanted subcutaneously in 3-week-old male rats for 7 weeks before extraction, followed by calcium analysis and histological examination via hematoxylin and eosin staining. No significant differences in mechanical properties were observed among the groups. The ethanol-treated groups (groups B and C; p < 0.05) exhibited significantly lower calcium levels than control (group A). Microscopy confirmed collagen and elastic fibers preservation, without significant immune cell variance. However, higher fibrocyte presence was noted in the ethanol-treated groups. This study presents a rapid anti-calcification protocol combining ethanol treatment with optimal GA fixation, suitable for direct surgical use of autologous tissues. Further research is necessary for long-term efficacy evaluation.

• 대한의용생체공학회:의공학회지
• /
• 제28권3호
• /
• pp.397-409
• /
• 2007

Owing to needs of biomechanical comprehension and analysis to obtain various medical treatment designs which are related with the spine in order to cure and diagnose LBP patients, the FE modeling and nonlinear analysis of lumbosacrum including a partial ilium and iliolumbar ligaments, were carried out. First, we investigated whether the geometrical configuration of vertebrae displayed by DICOM slice files is regular and normal condition. After constructing spinal vertebrae including a partial ilium, a sacrum and five lumbars (from L1 to L5)with anatomical shape reconstructed using softwares such as image modeler and CAD modeler, we added iliolumbar ligaments, lumbar ligaments, discs and facet joints, etc.. And also, we assigned material property and discretized the model using proper finite element types, thus it was completely modeled through the above procedure. For the verification of each segment, average sagittal ROM, average coronal ROM and average transversal ROM under various loading conditions(${\pm}10Nm$), average vertical displacement under compression(400N), ALL(Anterior Longitudinal Ligament) and PLL(Posterior Longitudinal Ligament) force at L12 level, strains of seven ligaments on sagittal plane at L45 level and maximal strain of disc fibers according to various loading conditions at L45 level, etc., they were compared with experimental results. For the verification of multilevel-lumbosacrum spine including partial ilium and iliolumbar ligaments, the cases with and without iliolumbar ligaments were compared with ROM of experiment. The results were obtained from analysis of the verified FE model as follows: I) Iliolumbar ligaments played a stabilizing role as mainly posterior iliolumbar ligaments under flexion and as both posterior and anterior iliolumbar ligaments of one side under lateral bending. 2) The iliolumbar ligaments decreased total ROM of 1-8% in total model according to various motion conditions, which changed facet contact forces of L5S level by approximately 0.8-1.4 times and disc forces of L5S level by approximately 0.8-1.5 times more than casewithout ilioligaments, under various loading conditions. 3) The force of lower discs such as L45 and L5S was bigger than upper discs under flexion, left and right bending and left and right twisting, except extension. 4) It was predicted that strains of posterior ligaments among iliolumbar ligaments would produce the maximum 16% under flexion and the maximum 10% under twisting. 5) It's expected that this present model applies to the development and design of artificial disc, since it was comparatively in agreement with the experimental datum.

• 척추신경추나의학회지
• /
• 제11권1호
• /
• pp.53-64
• /
• 2016

Objectives : The aim of this study is to assess the usage of diagnosis codes for somatic dysfunctions and the general characteristics of patients diagnosed with the code, by analyzing health insurance data provided by the Health Insurance Review & Assessment Service(HIRA) of Korea. This investigation is intended to outline future and willing to contribute to further use of diagnosis code and the approach of Oriental Medicine to somatic dysfunction. Materials and Methods : By analyzing HIRA data, those diagnosed with M99 codes, a code attributed to somatic dysfunction, were selected for analysis. Patients included were assessed for the relevant general characteristics, and the specific diagnostic criteria. The current usage rates and noteworthy characteristics of diagnostic codes of somatic dysfunctions were assessed. A comparative analysis between clinical departments and subcategories, and a comparative analysis to data of 2014 was conducted. Results : Patients given M99 codes constituted a small minority of all patients diagnosed in 2011 as shown by HIRA data. The codes were more frequently to older patients, females, outpatients, and those who filed for Health Insurance compensation. Medical institutions participating in the diagnosis were mostly primary care facilities, usually specializing in orthopedic(Western medicine sector) and internal medicine (Oriental Medicine sector). The most registered code in 2011 and 2014 was M995. The same trend can be observed in Oriental/Western medicine institutions and Public health center, on the other hand, between them, have some different patterns both 2nd and 3rd. Conclusions : This investigation is that of current usage of diagnostic codes of somatic dysfunction. HIRA insurance claim data was analyzed. Based on the current results, more precise diagnostic standards of somatic dysfunction are warranted. This study will provide a foundation for future Oriental Medicine approach to somatic dysfunctions.

• 대한의용생체공학회:의공학회지
• /
• 제25권5호
• /
• pp.361-367
• /
• 2004

척추체간 유합케이지의 성능평가에 있어서 압축강도와 상대적인 3차원적 안정성 그리고 골유도를 촉진시킬 수 있는 형상은 성공적인 골유합의 정도를 판가름 할 수 있는 중요한 척도이다. 새로 고안된 박스형 유합케이지 스파이크의 형상변화에 따른 척추체의 골단판에 미치는 응력분포 양상과 케이지의 안정성을 비교하기 위하여 압축하중 작용 초기에 스파이크 끝딘과 골단판이 접촉하는 경우와 스파이크가 골단판에 삽입되었을 경우를 구분하여 스파이크의 높이, 폭 및 각도를 변화시켜 가면서 유한요소 해석을 실시하여 고찰하였다. 유합케이지 2개가 척추체간에 삽입되어 있는 상태에서 수직하중 1700N이 가해질 때 척추체 골단판에 전달되는 응력분포를 조사하였으며, 전, 후방향으로 케이지 하나에 100N의 pull out하중을 부과하여 케이지의 스파이크 형상변화에 따른 미세이동 정도를 비교 평가하였다. 그 결과, 척추체 골단판의 응력 집중 정도에 가장 큰 영향을 미치는 요인은 케이지스파이크 끝단 폭의 크기이며, 케이지 스파이크의 높이 및 각도의 변화는 스파이크 끝단과 접촉하는 척추체 골단판에 미치는 응력 정도에 큰 영향을 미치지 않았다. 스파이크 경사면 각도조절 및 양방향혼합형의 대칭 배열을 통하여 전후방향 pull-out하중에 대한 변위량을 저감시킬 수 있었다. 본 연구의 결과를 통하여 척추체에서의 응력집중을 피할 수 있고 케이지의 초기 접촉시 골단판의 파괴를 방지하고 골유합에 유리한 케이지 스파이크 형상을 설계하였고, 케이지 치환술 후 운동시 전후방향으로 이동을 최소화하여 기계적 안정성을 높일 수 있는 새로운 척추체간 유합 케이지의 최적 형상을 제안하였다.

• 한국체육학회지인문사회과학편
• /
• 제57권6호
• /
• pp.293-308
• /
• 2018

본 연구는 알파인 스키와 관련하여 과거부터 최근까지 진행된 운동역학 연구의 동향을 파악하여 향후 운동역학 분야에서 진행되어야 할 연구 방향을 제언하고자 수행하였다. 운동역학 연구 분야에서는 스키 턴의 메커니즘과 스키어의 등급과 기술 수준에 따른 자세 분석, 스키와 눈의 마찰력, 공기저항 등의 연구가 주로 진행되었다. 이후 측정 센서와 컴퓨터 시뮬레이션을 활용한 연구에서는 IMU와 GPS 센서를 활용하여 스키 장비 개발 및 획득 데이터 검증에 연구가 진행되고 있다. 이와 같은 연구동향을 반영하여 추후 알파인 스키 분야에서 진행되어야 할 운동역학 연구에 대한 제언은 다음과 같다. 첫째, 기존 운동역학 분석 범위의 한계를 넘어 스키 전 구간이 분석 가능하고 스포츠 현장에서 간편하게 활용할 수 있는 측정 장비가 개발되어야 한다. 둘째, 측정 센서를 활용하여 획득한 정보의 정확도 향상과 이를 바탕으로 다양한 분석기법에 관한 연구가 지속적으로 진행되어 스포츠 현장에 도움이 될 수 있는 자료가 제공되어야 한다. 셋째, 컴퓨터 시뮬레이션을 활용하여 스키에서 발생하는 부상 메커니즘을 명확히 정립하고 부상을 예방할 수 있는 방안을 모색해야 한다. 넷째, 컴퓨터 시뮬레이션을 활용한 3차원 스키 모델을 개발하여 실제 주행데이터와 비교 검증함으로써 최적화된 스키 궤적 알고리즘 제공이 필요하다.

• 한국운동역학회지
• /
• 제17권2호
• /
• pp.177-185
• /
• 2007

Even though there were no clear definitions of the short game and short game distance, short game capability is crucial for a good golf score. Generally, chip shot and pitch shot are regarded as two principal components of the short game. Chip shot is a short, low trajectory shot played to the green or from trouble back into play. Pitch shot is a high trajectory shot of short length. Biomechanical studies were conducted usually to analyze full swing and putting motions. The purpose of the study was to reveal the kinematical differences between professional golfers' 30 yard $53^{\circ}wedge$ chip shot and $56^{\circ}wedge$ pitch shot motions. Fifteen male professional golfers were recruited for the study. Kinematical data were collected by the 60 Hz three-dimensional motion analysis system. Statistical comparisons were made by paired t-test, ANOVA, and Duncan of the SPSS 12.0K with the $\alpha$ value of .05. Results show that both the left hand and the ball were placed left of the center of the left and right foot at address. The left hand position of the chip shot was significantly left side of that of the pitch shot. But the ball position of the pitch shot was significantly right side of that of the chip shot. All body segments aligned to the left of the target line, open, at address. Except shoulder, there were no significant pelvis, knee, and feet alignment differences between chip shot and pitch shot. These differences at address seem for the ball height control. Pitch shot swing motions(the shoulder and pelvis rotation and the club head travel distance) were significantly bigger than those of the chip shot. Club head velocity of the pitch shot was significantly faster than that of the chip shot at the moment of impact. This was for the same shot length control with different lofted clubs. Swing motion differences seem mainly caused by the same shot length control with different ball height control.

• 대한치과보철학회지
• /
• 제40권5호
• /
• pp.507-524
• /
• 2002

Load transfer of implant overdenture varies depending on anchorage systems that are the design of the superstructure and substructure and the choice of attachment. Overload by using improper anchorage system not only will cause fracture of the framework or screw but also may cause failure of osseointegration. Choosing anchorage system in making prosthesis, therefore, can be considered to be one of the most important factors that affect long-term success of implant treatment. In this study, in order to determine the effect of anchorage systems on load transfer in mandibular implant overdenture in which 4 implants were placed in the interforaminal region, patterns of stress distribution in implant supporting bone in case of unilateral vertical loading on mandibular left first molar were compared each other according to various types of anchorage system using three-dimensional photoelastic stress analysis. The five photoelastic overdenture models utilizing Hader bar without cantilever using clips(type 1), cantilevered Hader bar using clips(type 2), cantilevered Hader bar with milled surface using clips(type 3), cantilevered milled-bar using swivel-latchs and frictional pins(type 4), and Hader bar using clip and ERA attachments(type 5), and one cantilevered fixed-detachable prosthesis(type 6) model as control were fabricated. The following conclusions were drawn within the limitations of this study, 1. In all experimental models. the highest stress was concentrated on the most distal implant supporting bone on loaded side. 2. Maximum fringe orders on ipsilateral distal implant supporting bone in a ascending order is as follows: type 5, type 1, type 4, type 2 and type 3, and type 6. 3. Regardless of anchorage systems. more or less stresses were generated on the residual ridge under distal extension base of all overdenture models. To summarize the above mentioned results, in case of the patients with unfavorable biomechanical conditions such as not sufficient number of supporting implants, short length of the implant and unfavorable antero-posterior spread. selecting resilient type attachment or minimizing distal cantilever bar is considered to be appropriate methods to prevent overloading on implants by reducing cantilever effect and gaining more support from the distal residual ridge.

• 대한물리치료과학회지
• /
• 제8권1호
• /
• pp.893-906
• /
• 2001

The purposes of this study were to compare pelvic tilt. range of motion(ROM) of hip rotation, and leg length difference before and after manipulation and to investigate correlation between changes of each variables after manipulation of sacroiliac pint in 31 low back pain patients(11 males, 20 females) with sacroiliac pint dysfunction. The sacroiliac pint of patients was manipulated on the side of anterior pelvic tilt, using the technique described by Stoddard(1962) and Greenmann (1996). I used this technique because it usually eliminated sacroiliac Pint dysfunction in one treatment session. SPSS for window computer system was used to analyze the data. Also t-test was performed for comparison of the variables before and after manipulation, and Pearson product-moment correlation analysis and regression analysis were performed for changes of each variables after manipulation. The result were as follows: 1. The pelvic tilt after manipulation was significantly decreased(mean=$2.79^{\circ}$) compared with the pelvic tilt before manipulation(p=.001). 2. The PROM of hip internal rotation ipsilateral to anterior pelvic tilt after manipulation significantly decreased (mean = $1.88^{\circ}$) compared with hip internal rotation before manipulation (p=.008). The PROM of hip internal rotation ipsilateral to posterior pelvic tilt after manipulation significantly increased(mean = $1.29^{\circ}$) compared with hip internal rotation before manipulation (p=.029). 3. The PROM of hip external rotation ipsilateral to anterior pelvic tilt after manipulation significantly increased(mean=$2.42^{\circ}$) compared with the hip external rotation before manipulation(p=$2.42^{\circ}$) compared with the hip external rotation ipsilateral to posterior pelvic tilt after manipulation significantly decreased(mean = $1.84^{\circ}$) compared with the hip external rotation before manipulation (p=.008). 4. Leg length difference after manipulation significantly decreased(mean=2.15 mm) compared with leg length difference before manipulation (p=.008). Regression analysis revealed that a fair correlation was found between change in leg length difference and change in anterior pelvic tilt after manipulation(p=.009). 5. Pearson product-moment correlation coefficient was used to assess differences of the variables after manipulation. A fair correlation was found between change in leg length difference and change in anterior pelvic tilt after manipulation(r=.462, p<.01). A fair correlation was found between change in anterior pelvic tilt and change in hip internal rotation ipsilateral to anterior pelvic tilt(r=.397, p<.05) and between change in anterior pelvic tilt and change in hip external rotation ipsilateral to anterior pelvic tilt(r=.516, p<.01). A fair correlation was found between change in posterior pelvic tilt and changes in hip internal rotation ipsilateral to posterior pelvic tilt (r=.441, p<.05) and between change in posterior pelvic tilt and change in hip external rotation ipsilateral to posterior pelvic tilt(r=.361, p<.05). A fair correlation was found between change in hip internal rotation ipsilateral to anterior pelvic tilt and change in hip external rotation ipsilateral to posterior pelvic tilt(r=.388, p<.05) and between change in hip internal rotation ipsilateral to posterior pelvic tilt and change in hip internal rotation ipsilateral to anterior pelvic tilt(r=.426. p<.05).

• 대한치과교정학회지
• /
• 제41권1호
• /
• pp.6-15
• /
• 2011

마이크로 임플란트 시술의 중요한 위험요인 중 하나로 치근접촉 문제가 있으나, 관련 연구는 결과 분석에 치중되어 있고, 치근접촉이 마이크로 임플란트 안정성 상실로 이어지는 기전에 대한 연구는 아직 미흡한 것으로 보인다. 이에, 본 연구에서는 생역학적 측면에서 그 영향을 분석하였다. Absoanchor 마이크로 임플란트(SH1312-7, Dentos Inc., Daegu, Korea) 첨부가 치근에 접촉되어 있을 때, 저작압 전달에 의한 마이크로 임플란트 변위가 인접골에 가하는 압축응력을 축대칭 유한요소모델을 사용하여 계산하였다. 요소별 응력이 해면골의 최대압축강도나, 치밀골의 비정상 골개조 임계능력을 넘을 경우 해당 요소를 순차적으로 해석모델에서 제거하며 실행한 6단계해석의 결과, 마이크로 임플란트에 인접한 해면골의 전체적인 파절과 과부하에 따른 치밀골의 비정상 골개조가 임플란트 지지력 상실에 주 요인이 될 것으로 평가되었다. 치밀골의 과부하 영역은 초기에는 치밀골판의 하부에 존재하였으나 상부로 확장되었고, 응력 재분포로 인한 감소효과 없이 양성 되먹임(positive feedback)으로 결국 치밀골 전 두께로 확대됨을 관찰하였다. 본 연구를 통해 치근접촉된 마이크로 임플란트가 인접골을 훼손시켜 안정성 상실로 이어지는 과정을 모사할 수 있었으며, 이로부터 치근접촉에 따른 마이크로 임플란트의 불량한 예후에 대한 생역학적 측면의 원인을 파악할 수 있었다.