• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.554-565
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• 2015

Objectives: The purpose of this study was to measure estheticians' grip and pinch strength in the hand parts and identify related factors according to general characteristics. Methods: A Jamar dynamometer was used to measure grip strength and a Jamar pinch gauge was used to measure tip, palmar and lateral pinch strength. General data were collected through a questionnaire survey among 116 estheticians from 31 skin care centers and spas. Results: The subjects' mean grip strength was 23.95 kgf for the right hand and 23.42 kgf for the left hand with the dominant right hand recording slightly higher mean grip strength. Their mean pinch strength was the highest with lateral pinch(right 4.89 kgf, left 4.69 kgf), which was followed by palmar pinch(right 3.77 kgf, left 3.88 kgf) and tip pinch(right 2.29 kgf, left 2.25 kgf), in that order. Conclusions: The grip and pinch strength of the hand parts was high when estheticians' commonly used both hands for massage instead of just one. The use of both hands is recommended to protect the hand parts during massage.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.120-125
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• 2006

In contrast to the conventional trigatron switch in which the currents are constricted by the z-pinch mechanical the new switch operates in an inverse pinch geometry formed by a pair of spiral electrodes in a sealed-off type. Inverse pinch switch greatly reduces hot spot formations and protects the electrode surfaces. The switch can be initiated with an electrical trigger electrode. Advantages of the new switch over the conventional switches are longer useful life, high current capability and lower inductance due to the dispersed and moving current sheet. These improved characteristics may make the inverse pinch switch suitable for pulse power systems.

• Journal of Korean Physical Therapy Science
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• v.20 no.1
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• pp.61-67
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• 2013

Purpose : The purpose of this paper is to figure out the effects of the Powerball exercise on grip strength, tip pinch and key pinch. Methods : Twenty subjects participated in this experiment. Spin right wrist counterclockwise for five minutes holding Powerball after making main joint of right hand -predominant hand- into elbow flexion and forearm pronation. Results : 1. Before and after Powerball exercise, when we compared the grip strength of men and women, there was a significant difference. 2. Before and after Powerball exercise, when we compared tip pinch of men and women, there was a significant difference. 3. Before and after Powerball exercise, when we compared key pinch of men and women, there was a significant difference. 4. Before and after Powerball exercise, there was no significant difference between men and women. Conclusion : From what using Powerball exercise influenced grip strength, tip pinch and key pinch positively, we assume that it will be considered a great expectation to improve grip strength, tip pinch and key pinch in the future and it would be better to conduct this experiment in depth to a lot of people.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1201-1216
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• 2017

In this study, we described the development of a methodology to measure tip-pinch strength on the paretic hand rehabilitation device and aimed to investigate reliability of the device. FSR sensors were embedded on the device, and tip pinch strength was estimated with data collected from the sensors using a developed equation while participants were demonstrating tip pinch. Reliability tests included inter-rater, test-retest, and inter-instrument reliability. B&L Engineering pinch gauge was utilized for the comparison. Thirty-seven healthy students participated in the experiment. Both inter-rater and test-retest reliability were excellent as Intraclass Correlation Coefficients (ICCs) were greater than 0.9 (p<0.01). There were no statistically significant differences in tip-pinch strengths. Inter-instrument reliability analysis confirmed good correlation between the two instruments (r = 0.88, p < 0.01). The findings of this study suggest that the two instruments are not interchangeable. However, the tip-pinch mechanism used in the paretic hand rehabilitation device is reliable that can be used to evaluate tip pinch strength in clinical environment and can provides a parameter that monitors changes in the hand functions.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.8
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• pp.277-283
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• 1983

The pulse generating circuit system of the so-called turbulently-heated theta pinch is experimentally investigated, and its results are compared with the predictions based on the conventional theory. The conventional theory assumes that the impedance of the pinch coil is independent on the time rate of change in voltage (or current) across the pinch coil. The experimental pulse height of the voltage actross the pinch coil is about 1.5% fo that predicted by the conventional theory.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2526-2531
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• 2005

A practical pinch torque estimator based on the Kalman filter is proposed for low-cost anti-pinch window control systems. To obtain the accurate angular velocity from Hall-effect sensor measurements, the angular velocity calculation algorithm is executed with additional procedures for removing the measurement noises. Apart from the previous works using the angular velocity estimates and torque estimates for detecting the pinched condition, the torque rate is augmented to the system model and the proposed pinch estimator is derived by applying the steady-state Kalman filter recursion to the model. The motivation of this approach comes from the idea that the bias errors in torque estimates due to the motor parameter uncertainties can be almost eliminated by introducing the torque rate state. For detecting the pinched condition, a systematic way to determine the threshold level of the torque rate estimates is also suggested via the deterministic estimation error analysis. Simulation results are given to certify the pinch detection performance of the proposed algorithm and its robustness against the motor parameter uncertainties.

• Nuclear Engineering and Technology
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• v.6 no.4
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• pp.249-252
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• 1974

The equilibrium configuration of the screw belt pinch is obtained as the first-order correction on that of the straight pinch of infinite lenghth.

• Archives of Plastic Surgery
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• v.40 no.1
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• pp.52-56
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• 2013

Background Measuring grip and pinch strength is an important part of hand injury evaluation. Currently, there are no standardized values of normal grip and pinch strength among the Korean population, and lack of such data prevents objective evaluation of post-surgical recovery in strength. This study was designed to establish the normal values of grip and pinch strength among the healthy Korean population and to identify any dependent variables affecting grip and pinch strength. Methods A cross-sectional study was carried out. The inclusion criterion was being a healthy Korean person without a previous history of hand trauma. The grip strength was measured using a Jamar dynamometer. Pulp and key pinch strength were measured with a hydraulic pinch gauge. Intra-individual and inter-individual variations in these variables were analyzed in a standardized statistical manner. Results There were a total of 336 healthy participants between 13 and 77 years of age. As would be expected in any given population, the mean grip and pinch strength was greater in the right hand than the left. Male participants (137) showed mean strengths greater than female participants (199) when adjusted for age. Among the male participants, anthropometric variables correlated positively with grip strength, but no such correlations were identifiable in female participants in a statistically significant way. Conclusions Objective measurements of hand strength are an important component of hand injury evaluation, and population-specific normative data are essential for clinical and research purposes. This study reports updated normative hand strengths of the South Korean population in the 21st century.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.14 no.2
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• pp.25-33
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• 2008

Purpose : This study was investigated the effect on grasp and pinch strength according to degree of flexion in elbow joint. Methods : Thirty male and thirty female students, aged 20 to 31 years were tested for using opened positioning with their shoulder abduction at $55^{\circ}$ and shoulder horizontal adduction at $30^{\circ}$ in four elbow flexion($0^{\circ}$, $45^{\circ}$, $90^{\circ}$, $135^{\circ}$). An electronic dynamometer(E-LINK V900s Evaluation System)and goniometer were used to measure grasp and pinch strength. Results : The average grasp strength of the dominant hand was strongest at elbow $45^{\circ}$ however, weakest at elbow $135^{\circ}$ flexion in both of male and female. The average pinch strength of the dominant hand was strongest at elbow $135^{\circ}$ flexion in both of male and female. The average pinch strength of dominant hand was weakest at elbow $45^{\circ}$ flexion in both of male and female. According to degree of elbow flexion in both of male and female, grasp and pinch strength was no significant statistically. In analyzing correlations, the grasp strength of male showed the most significant difference at elbow $45^{\circ}$ & $90^{\circ}$ flexion, and the pinch strength was most significant difference at elbow $0^{\circ}$ & $45^{\circ}$ flexion. Conclusion : In analyzing correlations, the grasp strength of female showed the most significant difference at elbow $90^{\circ}$ & $135^{\circ}$ flexion, and the pinch strength was most significant difference at elbow $45^{\circ}$ & $90^{\circ}$ flexion.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.1
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• pp.201-206
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• 2011

In using both hands, everyone dominantly use one hand and it is called left-handedness or right-handedness person. Measurements of grip and pinch strength provide objective indexes to represent functional integrity of the upper extremity. This study was conducted for thirty female college students(19 right-handedness and 11 lefthandedness). For assessment of the type of handedness, questionnaire was used; for grip strength, Jamar dynamometer was used; for pinch strength, Jamar pinch gauge was used. In right handedness, the grip and pinch strength of the dominant right hand was significantly higher than those of the non-dominant hand. In addition, regular exercises were shown to give influences on reduction of strength gaps between dominant and non-dominant hands. In both groups of left and right handedness, the grip and pinch strength of the dominant hand were significantly higher than those of the non-dominant hand, and regular exercises were shown to give influences on reduction of strength gaps between dominant and non-dominant hand.