• Tribology and Lubricants
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• v.21 no.1
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• pp.39-45
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• 2005

Investigation of the mass effect on the journal traces in the clearance of engine bearing has been performed for better design of mass distribution of crank system components such as crank pin, piston, con-rod, balance weight, crank throw weight, etc. as well as for better oil reaction behaviors to the applied forces from the cylinder pressures on the bearing. In this preliminary study, crank pin traces in the engine bearing clearance are computed by varying the equivalent magnitude of crank pin mass that includes the masses of crank pin, piston, con-rod. etc.. while most previous studies regarding journal traces in the bearing clearance neglect the inertia effects of crank pin mass. Although the inertia effect of pill mass is negligibly small compared to viscous force by ${\pi}bearing$ theory, it is found that it gives a great amount of influences on the journal traces in full bearing computation $(2\pi\;bearing\;theory)$ under the dynamic loading conditions.

• Journal of the Korean Geosynthetics Society
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• v.11 no.3
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• pp.11-17
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• 2012

This paper presents the results of investigation into bearing capacity of a geocell reinforced load base. In order to analyze variation of bearing capacity of the geocell reinforced road base comparing to without reinforced geocell road base, a series of full-scale tests were performed and measured using FWD (Falling Weight Deflectometer). The results indicate that bearing capacity of geocell (T=1.5 mm) reinforecd road base increase than the unreinforced road base.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.936-945
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• 1998

This study was performed to investigate the best surgical technique for normal stifle mobility by comparison with clinical signs and histopathological changes of articular cartilage after femoral trochleoplasty, trochlear chondroplasty and trochlear wedge recession. Twelve small mixed dogs who had grade I or II medial patellar luxation were used. The days that the dog had partial and full weight bearing were checked and histopathological changes 49 and 90 days after surgery were observed. The dogs had partial weight bearing in 3~6 days postoperatively and full weight bearing in 20~24 days. After femoral trochlepoplasty, the articular surface was irregular and rough, but smooth after trochlear chondroplasty and trochlear wedge recession. Histopathologic examination performed on the 49th and 90th days after femoral trochleoplasty revealed that articular surface was occupied by fibrocartilage but the hyaline cartilages are preserved after trochlear chondroplasty and trochlear wedge recession. In trochlear wedge recession, the wedges of all cases were firmly attached to underlying subchondral bone which were indicating complete healing. The results of this study suggested that the trochlear wedge recession was the best chondroplasty for correcting patellar luxation.

• Journal of Korean Foot and Ankle Society
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• v.27 no.1
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• pp.12-16
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• 2023

Purpose: Postoperative exercise for acute Achilles tendon rupture is important for a patient's return to daily life and sports. On the other hand, the protocol requires considerable effort to educate patients and continuous checking. This study evaluated the outcome of a new simple and delayed rehabilitation protocol after Achilles tendon rupture repair. Materials and Methods: From July 2014 to November 2020, one hundred eighty-three patients were operated on by one surgeon. The exercise protocol was classified into two methods. One group (immediate protocol, control group) started immediate full weight bearing with a 20° plantar flexion range of motion from two days postoperatively. Ankle dorsiflexion was restricted to 0°. The other group (delayed protocol, case group) started full weight bearing with a controlled ankle motion boot from two weeks postoperatively. No range of motion exercise was allowed until six weeks postoperatively. Age, sex, body mass index, ankle range of motion, muscle power, time to return to previous physical activity, functional score, and complication rate were evaluated. The results of the two groups were compared using a Mann-Whitney test. Statistical significance was set as p<0.05. Results: The range of motion, double heel rising, and one-leg standing were achieved faster in the control group (p<0.05). However, single-heel rising, repeated single-heel rising, return to previous activity (work, run, and sport), and functional scores showed no statistical difference (p>0.05). Conclusion: Simple and delayed postoperative rehabilitation of acute Achilles tendon rupture without active range of motion exercises showed satisfactory functional results and a low complication rate.

• Archives of Reconstructive Microsurgery
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• v.8 no.2
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• pp.108-114
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• 1999

In general, amputation has been performed in the treatment of diabetic foot which doesn't respond to the conservative treatment. We have evaluated the existence of post-operative infection, the morbidity of donor site, the degree of recovery of sensation, weight bearing ambulation and recurrence in the 6 cases(5 patients) of diabetic foot patients among the 230 cases of free flap transfer done in our department. In all cases of free flap transfer to diabetic foot, 100% of survival rate was shown. The sensory recovery was more than average of 40% of the area of the transferred flap, and two points discrimination was shown average of 5cm as a result. In all cases, no evidence of post-operative infection was discovered and the weight bearing gradually became easier, and at the average of 5 months after operation, the full weight bearing ambulation became possible. If the infection of diabetic foot and the level of blood sugar could be controlled successfully, the free flap transfer could be considered one of the treatment option to avoid amputation.

• Journal of Korean Foot and Ankle Society
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• v.26 no.3
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• pp.118-122
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• 2022

Although total ankle arthroplasty (TAA) has increased considerably in the past ten years, reflecting improvements in implant design and survivorship, the clinical outcomes have been less satisfactory than total hip or total knee arthroplasties. Several issues under debate include postoperative management and rehabilitation in TAA. Especially, there is no consensus or evidence for the most appropriate postoperative management and rehabilitation for patients undergoing TAA. This study was therefore undertaken to suggest appropriate postoperative management and rehabilitation in TAA, after reviewing published articles and focusing on the following topics: prehabilitation, hospital stay, immobilization type and duration, weight-bearing management, pharmacological treatment, and adopted rehabilitation protocols. In previous studies, the postoperative management and rehabilitation proposed depended on the surgeon's preference, the patient's characteristics, and the associated surgical procedures performed after TAA. Nonetheless, our research indicates the best approach is to include a prehabilitation program, immobilization in the early postoperative stage (2~4 weeks), range of motion exercise with partial weight-bearing ambulation, followed by full weight-bearing ambulation after six weeks. Further studies are required to develop a standardized rehabilitation protocol and improve the overall quality of care after TAA.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.2
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• pp.249-253
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• 1995

The fibrous dysplasia is a progressive and disabling condition that lead to deformity, especially weight bearing bones. The morbidity that is associated with the polyostotic fibrous dysplasia is the recurrent fracture and deformity. Various methods of treatment had been failed to control this problem. We used osteotomy and reconstruction nailing for polyostotic fibrous dysplasia occured in the proximal part of right femur with varus deformity and reconstruction nailing in left femur without osteotomy, and interlocking intramedullary nailing in right tibia to prevent pathologic fracture. These methods brought a good result of bone union and full weight bearing ambulation after 1 year and 6 month follow up. We think these methods are useful methods to control refracture and deformity, so we reported this case with bibliographic reviews.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.401-414
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• 2010

Top Base Foundation(TBF) is a stabilization method for light weight structures particularly in the soft ground. It is widely used for the increment of bearing capacity and restraining settlement of foundations when the bearing capacity of ground is not enough. However, when the design values from exiting Japanese standard are compared with the observation values from the field measurement, the bearing capacity of exiting standard estimated smaller For this reason, it is necessary to establish more reasonable prediction technique considering to understand the behavior of TBF in soft ground. In this study, 1/5 scale model tests were performed in the laboratory. Also, full scale tests were carried out in order to investigate the behavior of TBF with various shapes. In addition, about 100 sites measurement data were evaluated to investigate the behavior of TBF in various ground conditions. Based on the results of the model tests and field measurement data, it was possible to establish more reasonable the bearing capacity equation of TBF considering various N-value of soil, the effect of underground water and failure shapes.

• Journal of Korean Foot and Ankle Society
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• v.17 no.2
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• pp.136-142
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• 2013

Purpose: To analyze the outcome of distal tibia fracture treated with the Distal Tibia LCP with combination of interfragmentary screw. Materials and Methods: Between January 2008 and March 2012, data of 34 patients with fracture of distal tibia treated with the Distal Tibia LCP with or without combination of interfragmentary screws were reviewed. There were 17 males and 17 females with an average age of 51.8 years (range, 18~77 years). Radiographic union time and time from surgery until ability to full weight bearing were measured and compared. Callus index was measured as quotient of callus thickness and diameter of corticalis both in AP and sagittal direction. Results: 12 fractures were treated with interfragmentary screws and 22 fractures were treated with bridging plate alone. In interfragmentary fixation group, time to full weight bearing was 14 weeks versus 15.75 weeks without screw. Callus index at bearing was not significantly lesser in patients with screw compated with those without, but callus index difference at posterative 4weeks was sigficant. Radiologic union time was 11.3 weeks in interfragmentary fixation group and 12.58 weeks without screw. Conclusion: The osteosynthesis with the Distal tibia LCP with combination of interfragmentary screw seems to be more stable in postoperative 4weeks than Distal tibia LCP alone, expecting to earlier ROM exercise and rehabilitation.

• Physical Therapy Korea
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• v.9 no.1
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• pp.17-42
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• 2002

The purpose of this study was to investigate the treatment effect of three interventions on the disuse atrophy of rat hindlimb after two weeks suspension. Forty-eight 11~12 weeks old female Sprague-Dawley white rats were divided into four intervention groups: 1) suspension only (S; n=10), 2) intensive weight bearing treadmill (IWBT; n=10), 3) electrical stimulation (ES; n=9), 4) 2)+3) (ES/IWBT; n=9). Another 10 rats received no intervention or hindlimb suspension and served as controls (C). After the interventions, 1) the cross-sectional area (CSA), 2) the ratio of white muscle fiber composition (WMFC), 3) isometric tetanic tension (ITT), and 4) muscle weights (MWs) were measured from the four calf muscle specimens. The results were as follows: 1. In all intervention groups, the CSAs of medial and lateral gastrocnemius (MG LG), soleus (SOL), and flexor digitorum superficialis (FDS) decreased when compared to the control (C) group (p<.05). The CSA increased in FDS and LG for the IWBT group, in SOL for the ES/IWBT group compared to the S only group (p<.05). 2. The ratios of WMFC in MG, LG, SOL, and FDS increased compared to the C group for all interventions (p<.05). The ratios of WMFC decreased in SOL and LG for the IWBT group, in SOL for the ES/IWBT group compared to the S only group, and decreased in SOL for the ES/IWBT group compared to the IWBT group (p<.05). 3. The ITT in the MG, LG, SOL, and FDS decreased compared to the C group for all interventions (p<.05). The ITT increased in MG LG/FDS, SOL, and the whole calf muscles (WCMs) in the IWBT, ES and ES/IWBT groups compared to the S only group (p<.05). 4. The MWs in MG LG/FDS, SOL, WCMs decreased compared to the C group for all interventions (p<.05). The MWs increased in MG LG/FDS and WCMs for the IWBT group, in SOL for the ES group, and in SOL for the ES/IWBT group compared to the S only group (p<.05). 5. In atrophied muscles, the IWBT group showed the best recovery and the ES/IWBT and ES groups followed in decreasing order. The most susceptible muscle to disuse atrophy was the SOL. But conversely, it showed the best recovery in the ES/IWBT group. After two weeks of hindlimb suspension, the calf muscles of rats atrophied and their isometric tension decreased. These changes were best reversed by hindlimb-focused treadmill activity. The next best results were achieved by electrical stimulation combined with the treadmill followed by only electrical stimulation. These findings indicate that full weight bearing treadmill activity alone or in combination with electrical stimulation are effective treatments for non-weight bearing induced muscle atrophy. Further study of the effect of different intensities of electrical stimulation and variations in the duration period of full weight bearing treadmill activity on disuse atrophy is recommended.