• 한국전문물리치료학회지
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• 제12권4호
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• pp.33-40
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• 2005

The purpose of this study was to define more precisely the anatomy of the thumb flexor pulley system and to determine the relative contribution of each of the pulleys to the biomechanics of thumb motion at the metacarpophalangeal (MP) and interphalangeal (IP) joints. For this, 22 hands from 11 cadavers were used and randomly assigned to two groups. In the first group, the first annular (A1) pulley was cut first followed by the variable annular (Av) pulley and then the oblique pulley. In the second group, the oblique pulley was cut first followed by the, pulley and then the Av pulley. In 7 of 22 hands, it was a transverse structure parallel to the, pulley with a gap between the A1 and Av pulleys, referred to here as type I. In 9 hands, the A1 and Av pulleys were connected without any gap (type II). In 6 hands, the space between the A1 and Av pulleys were triangular in shape with fibers of the Av pulley converging toward the radial side (type III). In biomechanical study of both first and second experiments, there was no significant difference in MCP joint flexion between the all intact, A1 section, A1/Av section, A2 intact (A1/Av/oblique section), and no pulley configuration (p>.05). In occurring displacements less than 10 mm, there was no significant difference in IP joint flexion (p>.05). However, there was a significant decrease in IP joint flexion occurred in both 15 mm and 20 mm excursion (p<.05), when the oblique pulley was resected additionally after cutting the A1 and Av pulleys in first experiment, and when the A1 pulley was resected additionally after cutting the oblique pulley. According to the results, the injury of only the oblique pulley does not decrease thumb motion significantly. The oblique pulley injury with both the A1 and Av pulleys laceration decreased thumb motion significantly. The additional laceration of the A2 pulley does not decrease thumb motion.

• Archives of Plastic Surgery
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• 제37권2호
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• pp.187-190
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• 2010

Purpose: Pediatric trigger thumb is a condition of flexion deformity of the interphalangeal (IP) joint. The known surgical treatment is the release of the flexor pollicis longus by transection of the A1 pulley. We report two cases of pediatric trigger thumb that were resolved by releasing of additional pulley as well as A1 pulley. Methods: From March 2006 to April 2008, a total of 10 children with trigger thumb were operated. In two cases, transection of only the A1 pulley was insufficient to relieve the triggering. When more distally dissection, we found an additional pulley. After release of the additional pulley, the full extension of IP joint is obtained. Results: There were no significant complications. In 8 cases, the trigger thumbs were resolved by transecting only the A1 pulley, does not extend beyond the base of the proximal phalanx. In one case, the additional pulley was found to be more distal to the A1 pulley. It was necessary to extend the release up to the half in the proximal phalangeal shaft. In other case, the additional pulley was immediately adjacent to the A1 pulley. Conclusion: In most cases of trigger thumb, division of just A1 pulley is sufficient to relieve the triggering. However, dividing the A1 pulley in two patients proved to be insufficient to relieve the flexed deformity. In these cases, we found that the additional pulley, different from previous known A1 pulley, had existed, which must be transected to allow full excursion of flexor pollicis longus.

• International journal of advanced smart convergence
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• 제9권1호
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• pp.10-18
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• 2020

In the case of a belt-pulley type CVT that transmits a driving force by using a variable pulley and a metal belt, slippage occurs due to transmission of power by using a belt, which results in a decrease in efficiency. Therefore, in this study, the rails were machined on the plate surface of the pulley to reduce the friction and slip between the belt and the pulley while applying the characteristics of the CVT. As the plate is rotated by the shape of the rail, a centrifugal belt pulley type continuously variable transmission system which shifts while varying the radius of rotation of the belt that transmits power is studied. Accordingly, the structure of the pulley was designed and the centrifugal belt pulley type continuously variable transmission was Manufactured. In addition, to verify the suitability of the manufactured transmission, the power transmission efficiency was monitored by establishing an interface with the controller. The structural analysis of the plate proved the suitability of the centrifugal belt pulley type continuously variable transmission.

• Archives of Plastic Surgery
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• 제51권1호
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• pp.110-117
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• 2024

Percutaneous first annular pulley (A1 pulley) release, which has been increasingly used to treat trigger fingers, has been widely established as a safe and simple procedure. Multiple studies have reported positive results of percutaneous A1 pulley release. In this study, however, we report cases of patients who developed complications after undergoing percutaneous A1 pulley release at local clinics. A total of six patients visited our hospital for infectious complications after percutaneous A1 pulley release. Various sequelae such as damage to normal structures, insufficient procedure, and tissue necrosis were observed during the exploration. A retrospective study was conducted to identify the cause and trend of the observed complications by instruments (HAKI knife or needle). In the HAKI knife group, there was a tendency for damage to normal structures, while in the needle group, an insufficient release or serious soft tissue necrosis was observed. Based on these cases, our findings confirm the existence and characteristics of infectious complications following the percutaneous A1 pulley release. We further identify that the type of instrument used predicts the nature of complications. Thus, reliable and skilled performance of the procedure by experts is essential for safe treatment.

• Journal of Biosystems Engineering
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• 제24권2호
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• pp.99-106
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• 1999

This study was conducted to provide a direction for improving the performance of triangular-type belt clutch. The power transmission characteristics and the wear of belt were investigated for two types of pulley set theoretically and experimentally. The results of research were summarized as follows: 1) Based on the theoretical analysis for the life time of belt, the wear of belt could be reduced by increasing the sizes of driving V-pulley and tension pulley, and by decreasing the tension on V-belt. 2) The pulley set # 2 could transmit more power than the pulley set # 1 could at the same slop rate. While the slip rate was 2.36% on the pulley set # 2 at the maximum power transmission, the slip rate on the pulley set # 1 was increased up to 12.2% at the same condition. 3) From the 16 hours' fatigue test, the wear of belt used n the pulley set # 1 was observed severer than that in the pulley set#2. Also, it was found that the tensile strength of belt used in the pulley set # 2 was greater than that of belt used in the pulley set # 1.

• Archives of Reconstructive Microsurgery
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• 제23권1호
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• pp.29-32
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• 2014

Few articles have been written about the flexor tendon sheath ganglion in the finger, especially, between A1 pulley and A2 pulley. We report on rare cases of flexor tendon sheath ganglion with one symptomatic and two asymptomatic. All masses were evaluated using real-time ultrasonography and well-defined anechoic cystic lesions with posterior enhancement were observed. A 17-year-old female had a small mass at the 4th metacarpophalageal joint of her right hand, with pain and triggering. The patient underwent simple excision and a ganglion measuring $1.0{\times}0.8$ cm in size was derived from Camper's chiasm, between A1 pulley and A2 pulley. In two asymptomatic cases, ganglia measuring less than 0.5 cm in size observed. Based on our experience, real-time ultrasonography would be an excellent diagnostic modality in determining the treatment method in flexor tendon sheath ganglia, and surgical excision is recommended in symptomatic, especially triggering patients.

• 대한기계학회논문집A
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• 제30권9호
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• pp.1041-1048
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• 2006

The pulley is one of core mechanical elements in the power steering system for vehicles. The pulley operates under both the compressive loading and the torque. Therefore, to assure the safety of the power steering system, it is very important to investigate the durability and the optimization of the pulley. In this study, the applied stress distribution of the pulley under high tension and torsion loads was obtained by using finite element analysis. Based on these results the fatigue life of the pulley with the variation of the fatigue strength was evaluated by a durability analysis simulator. The results at 50% and 1% for the failure probability were compared with respect to the fatigue life. In addition to the optimum design for the fatigue life is obtained by the response surface method. The response function utilizes the function of the life and weight factors. Within range for design life condition the minimization of the weight, one of the formulation, is obtained by the optimal design. Moreover the optimum design by considering its durability and validity is verified by the durability test.

• 대한정형외과스포츠의학회지
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• 제2권1호
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• pp.71-76
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• 2003

견관절증에 대한 관절경검사중분리된이두박건활차(detached biceps pulley)를발견하였으며 그임상적의의를고찰하고자한다. 견관절의병변에 대한관절경 치료 시3예의분리된 이두박건활차의 양상을확인하였으며, 그유발원인은 각각 반복적인투구, 전방견관절불안정성및외상등으로생각되었다. 분리된이두박건활차가상완운동에따른관절내활주를통해후상방관절순에충돌을유발하는것을관찰하였다. 불안정성예에대해서는전방관절순수복술후충돌징후가감소하였으며, 나머지2예에서는충돌징후를유발하는이두박건활차를절제후증상의호전을볼수있었다.

• 동력기계공학회지
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• 제17권1호
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• pp.85-90
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• 2013

Dry CVT consists of a driving pulley and a driven pulley joined by rubber V-belt. Each pulley consists of a fixed flange and a movable flange. The movable flange moves toward a fixed flange under the actuation of a centrifugal roller, as the driving pulley speed increases. The important claim which have an influence on the performance of the Dry CVT is the wear of the centrifugal roller. In this study ball type is proposed instead of roller type of movable flange to resolve the claim. Simulation is carried out for new model to verificate performance, experiments are carried out for new model to evaluate performances.

• Clinics in Shoulder and Elbow
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• 제16권1호
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• pp.47-52
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• 2013

상완 이두근 장두 활차의 병변은 종종 견관절 통증과 기능저하의 원인 되기도 한다. 이 병변으로 인하여 상완 이두근 장두의 불안정성과 견갑하건 및 극상건의 관절내 부분 파열이 야기되기도 한다. 이러한 활차 병변에 대하여 관절경적 봉합술을 시행하는 것에 대하여는 이견이 존재하는데, 이는 상완 이두근 장두의 건 절단술이나 건 고정술이 더 예측 가능한 결과를 제공하기 때문이다. 이 종설의 목적은 상완 이두근 장두 활차의 구조와 손상 기전 및 치료에 대한 정보를 제공하기 위함이다.