• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.1
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• pp.81-87
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• 2012

The structural and biomechanical characteristics of pelvic and foot are important factors of back pain, but it is still complicated to clearly explain the relationship among them. The purpose of this study was to find out the characteristic of pelvic parameters and biomechanics of foot in patients with low back pain. Thirty-three female subjects with chronic low back pain were enrolled and ODI and VAS score were measured for back pain index. All subjects were taken the X-ray examination for major pelvic parameters and foot scan analysis for foot pressure, gait angle, fore-foot/rear-foot peak pressure ratio and asymmetric index. Statistical analysis were performed to examine the inter-relation between the measurement. As a result, it was shown the positive interrelation between back pain and F/R ratio, but others were not shown the relationship related to low back pain. And there were correlations between the lumbo-pelvic structure and biomechanics of foot in some aspects, but the causal relationship between them are still indefinable. In order to get more information about structures and biomechanics related to low back pain, subsequent researches are needed.

• Korean Journal of Applied Biomechanics
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• v.30 no.4
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• pp.285-291
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• 2020

Objective: Shoes midsole are crucial for reducing impact forces on the lower extremity when someone is running. Previous studies report that the cushioning of running shoes make it possible to use less muscular energies. However, the well cushioned shoes result in energy loss as the shoe midsole is compressed. Cushioning reduces the load on the body, it also results in the use of more muscle energy to create propulsion force. The purpose of this study was to investigate the effect of the difference of shoe hardness & resilience on the running. Method: Shoes midsole are crucial for reducing impact forces on the lower extremity when someone is running. Previous studies report that the cushioning of running shoes make it possible to use less muscular energies. However, the well cushioned shoes result in energy loss as the shoe midsole is compressed. Cushioning reduces the load on the body, it also results in the use of more muscle energy to create propulsion force. The purpose of this study was to investigate the effect of the difference of shoe hardness & resilience on the running. Results: In vastus lateralis muscle Activation, Type 55 were significantly higher for Type 50 and X (p=0.019, p=0.045). In Gluteus Maximus muscle activation, Type 55 was significantly lower for type 50 (p=0.005). In loading late, Type 55 and X were significantly higher for type 45 (p=0.008, p=0.006). Conclusion: The components of a shoe are very complex, and there can be many differences in manufacturing as well. Although some differences can be found in the biomechanical variables of the high elastic midsole, it is difficult to interpret the performance enhancement and injury prevention.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.4
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• pp.109-119
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• 2023

PURPOSE: The definition and scope of biofeedback are broad and lack a clear framework. Therefore, efforts are needed to clearly understand the exact range and definition of biofeedback based on the research and development conducted to date. Thus, the purpose of this study was to arrive at the definition and scope of biofeedback through a literature review and analysis of its application methods. METHODS: This study is a systematic literature review conducted to understand the various types and effects of biofeedback. International databases such as Google Scholar and PubMed were used. Domestic databases utilized for keyword searches included the Research Information Sharing Service (RISS) and the National Digital Science Library (NDSL). Quality assessment of the selected studies in the selection process was done using the Cochrane risk of bias, and the research was analyzed according to the population, intervention, control, and outcomes (PICO) format. RESULTS: Studies conducted between 2019 and 2021 were selected, with 4 papers falling under physiological classifications and 7 under biomechanical classifications. The quality assessment results showed that random sequence generation, allocation concealment, performance bias, and reporting bias were unclear. Detection bias was moderate, and attrition bias and other biases were low. Out of the 11 papers, 9 dealt with physical function outcomes, 5 with daily life activities, and 3 with mental functions. CONCLUSION: Physiological biofeedback tended to influence psychological factors more than physical functions, while biomechanical biofeedback tended to have a positive impact on physical functions.

• Clinics in Shoulder and Elbow
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• v.27 no.1
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• pp.88-107
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• 2024

The aim of this systematic review was to collect evidence on the following 10 technical aspects of glenoid baseplate fixation in reverse total shoulder arthroplasty (rTSA): screw insertion angles; screw orientation; screw quantity; screw length; screw type; baseplate tilt; baseplate position; baseplate version and rotation; baseplate design; and anatomical safe zones. Five literature libraries were searched for eligible clinical, cadaver, biomechanical, virtual planning, and finite element analysis studies. Studies including patients >16 years old in which at least one of the ten abovementioned technical aspects was assessed were suitable for analysis. We excluded studies of patients with: glenoid bone loss; bony increased offset-reversed shoulder arthroplasty; rTSA with bone grafts; and augmented baseplates. Quality assessment was performed for each included study. Sixty-two studies were included, of which 41 were experimental studies (13 cadaver, 10 virtual planning, 11 biomechanical, and 7 finite element studies) and 21 were clinical studies (12 retrospective cohorts and 9 case-control studies). Overall, the quality of included studies was moderate or high. The majority of studies agreed upon the use of a divergent screw fixation pattern, fixation with four screws (to reduce micromotions), and inferior positioning in neutral or anteversion. A general consensus was not reached on the other technical aspects. Most surgical aspects of baseplate fixation can be decided without affecting fixation strength. There is not a single strategy that provides the best outcome. Therefore, guidelines should cover multiple surgical options that can achieve adequate baseplate fixation.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.680-688
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• 2018

Objective : To mitigate the risk of iatrogenic instability, new posterior decompression techniques able to preserve musculoskeletal structures have been introduced but never extensively investigated from a biomechanical point of view. This study was aimed to investigate the impact on spinal flexibility caused by a unilateral laminotomy for bilateral decompression, in comparison to the intact condition and a laminectomy with preservation of a bony bridge at the vertebral arch. Secondary aims were to investigate the biomechanical effects of two-level decompression and the quantification of the restoration of stability after posterior fixation. Methods : A universal spine tester was used to measure the flexibility of six L2-L5 human spine specimens in intact conditions and after decompression and fixation surgeries. An incremental damage protocol was applied : 1) unilateral laminotomy for bilateral decompression at L3-L4; 2) on three specimens, the unilateral laminotomy was extended to L4-L5; 3) laminectomy with preservation of a bony bridge at the vertebral arch (at L3-L4 in the first three specimens and at L4-L5 in the rest); and 4) pedicle screw fixation at the involved levels. Results : Unilateral laminotomy for bilateral decompression had a minor influence on the lumbar flexibility. In flexion-extension, the median range of motion increased by 8%. The bone-preserving laminectomy did not cause major changes in spinal flexibility. Two-level decompression approximately induced a twofold destabilization compared to the single-level treatment, with greater effect on the lower level. Posterior fixation reduced the flexibility to values lower than in the intact conditions in all cases. Conclusion : In vitro testing of human lumbar specimens revealed that unilateral laminotomy for bilateral decompression and bone-preserving laminectomy induced a minor destabilization at the operated level. In absence of other pathological factors (e.g., clinical instability, spondylolisthesis), both techniques appear to be safe from a biomechanical point of view.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.424-433
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• 2019

The purpose of this study was to investigate the effects of gender difference in injury experience on biomechanical variables of lower extremity during two leg drop landing. 20 male(injury experience=8, non-injury experience=12) and 20 female(injury experience=11, non-Injury Experience=9) in their 20's were selected as subjects. Two-way mixed ANOVA was performed on the biomechanical variables obtained from the two leg drop landing in a 45cm height box and post-test was performed with bonferroni adjustment(p <.05). The results of this study suggest that the group of female who injury experience could induce the reduction of the peak vertical ground reaction force by increasing the valgus and internal rotation of the knee joint and flexion and internal rotation of the hip joint. In the INE(injury non-experienced) female group, the peak knee flexion angle was the smallest, as well as the flexion of the hip joint and the external rotation angle, and the peak vertical ground reaction force was the highest. On the other hand, the INE female group showed high vertical ground reaction force because they did not utilize the knee and hip joints relatively than the IE(injury experienced) female group, this means that it is relatively exposed to the risk of injury. Therefore, it was found that gender difference in injury experience is a factor affecting factors of knee and hip joint movement and peak vertical GRF(ground reaction force).

• Journal of Biosystems Engineering
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• v.35 no.3
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• pp.206-213
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• 2010

The purpose of this study is to analyze musculoskeletal injuries in combine harvesting operation using a digital human model. In order to analyze problems in combine harvesting operation, the operations were broken into 5 work processes and then we preformed ergonomic and biomechanical analyses such as RULA test, Comfort Assessment and joint kinetic analysis for the each process. As a result, there was a clear need to change the combine operating environment, as the RULA score ranged from 4 to 7. In addition, we could find two major musculoskeletal injury factors which are the standing posture with upperbody forward tilting and inappropriate location of operating levers.

• Journal of Korean Neurosurgical Society
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• v.41 no.1
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• pp.61-64
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• 2007

Lumbo-sacral junction is a transition lone between the mobile lumbar spine and immobile pelvis. Lumbosacral junction has been considered to be the most troublesome portion of the spine to be fused because of the difference in anatomical and biomechanical factors between spine and pelvis. A metastatic sacral tumor in a 57-year-old man was resected, followed by unilateral lumbo-iliac fixation across lumbosacral junction using modified Galveston technique. Rigid fixation was successfully achieved. Detailed anatomy and surgical techniques are presented.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.2
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• pp.105-108
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• 2003

After stage-two surgery, the highest incidence of failure has been attributed to implant overload. However, the biomechanical factors cited inthe literature that contribute to implant overload, such as bone type, cuspal inclination, horizontal offset, maxillary compared to mandibular arch, the inclusion of natural teeth within the prosthesis, and occlusal harmony are superimposed on physiologic variations. Following two cases, including reduction of cuspal inclination and usage of modified incisal pin, showed a method of contouring occlusal surface for reduction of unpreditable implant overload.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1458-1460
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• 2008

Tissue engineering is an interdisciplinary field that utilizes the principles of engineering and life sciences toward the creation of biological substitutes. Traditionally, major components of tissue engineering are cells, scaffolds, growth factors and recently biomechanical aspects have been given much attention. A large number of studies have reported that mechanical signals are of particular interest in either encouraging or inhibiting cellular responses. In tissue engineering, cell adhesion is a very important step, because quality of adhesion may determine a cell fate in the future. Elasticity of cell-adhesive substrate is found critical in regulating stem cell differentiation. Cells exert different contractile forces for cell migration, depending on substrate mechanics. Though tissue engineering is very interactive with diverse expertise, for a breakthrough, principles of biomechanics in tissue and cell level needs to be fully understood.