Study on the grip spans of combination pliers in a maximum gripping task

Kim, D.M.,Choi, K.H.,Lee, S.Y.,Kong, Y.K. Elsevier 2016 International journal of industrial ergonomics Vol.54 No.-

A newly developed system was applied in this study to evaluate the effects of the grip spans (45-80 mm) of combination pliers on the total grip strength, individual finger force, resultant force, and subjective discomfort. A total of twenty-six males participated and were asked to exert their maximum grip strength with two repetitions. The highest and the lowest total grip strength and resultant force (311.8 N and 737.9 N vs. 210.1 N and 501.7 N) were obtained at a 60 mm and 80 mm grip spans, respectively. In general, the participants considered the 50 and 60 mm grip spans as being the least discomfort, whereas the 80 mm grip span was considered as the most discomfort grip span in a maximum grasping task. The results can be utilized as basic data for the manufacturing and design industries of two-handle hand tools, such as pliers and wrenches. Practitioners summary: Custom-made combination pliers were applied in this study to evaluate grip strength, resultant force, and subjective discomfort, relative to five grip spans. The authors expect that the results of the present study will provide valuable information for the designers and users of pliers.

Evaluation of pliers in a maximum gripping task

Yong-Ku Kong,Min-Tae Seo,Ji-Soo Kim,Hyun-Sung Kang 대한인간공학회 2013 대한인간공학회 학술대회논문집 Vol.2013 No.5

Objective: The objective of this study is to derive the optimal grip span of pliers in a maximum gripping task. Background: Although many previous studies have been performed for I-Type and cylinder-type handles and evaluated their various grip span size, there are only few studies regarding on A-Type handles such as pliers. Methods: A total of 25 males participated in this experiment and conducted maximum gripping task using custom-made pliers with three grip spans (50, 70, and 90㎜). The effects of grip spans on grip strength, muscle activity, and subjective discomfort were analyzed. Results: The experimental results showed that total grip strength of 50㎜ grip span had significantly higher than another grip spans. Subjective discomfort showed that the discomfort rating of radius side of the palm was higher than most other parts, significantly. The %MVC of the muscle has no significant difference in three grip span. Conclusion: It was recommended to use the 50mm grip span to exert the maximum grip strength with similar muscle activities in uses of pliers. Application: This finding is expected to be used as the basic data for designing proper pliers.

Grip Strength of Pliers on the Maximum Gripping Task for Females

Yong-Ku Kong,Dae-Min Kim,Ji-Soo Park,Sung-Yong Lee,Kyeong-Hee Choi 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.11

Objective: The primary purpose of this study was to evaluate the effects of various grip spans of pliers on the resultant force and subjective discomfort in female users. Background: Despite the automation of facilities, many workers were still using hand-tools such as wrench, screwdriver, and pliers. Those hand-tool users are having trouble with hand-related musculoskeletal disorders. Especially females tend to have a higher rate of hand-related musculoskeletal disorders than males. Method: A total of 26 females who had no history of upper extremity musculoskeletal disorders (MSDs) were participated in this study. All female participants were asked to exert a maximum grip force with three repetitions, and to report the subjective discomfort rating for five grip spans of pliers (45, 50, 60, 70, 80mm). Results: Results showed that the effects of grip span were statistically significant on the total grip strength, resultant force, and subjective discomfort rating in this study. The lowest total grip strength was obtained from the grip span of 80mm. For resultant force, the 50mm and 60mm grip spans showed also significantly higher resultant force. The lowest subjective discomfort was observed in the 50mm span. Conclusion: Based on the study, the 50mm and 60mm grip spans which provided highest resultant force as well as lowest discomfort rating might be recommendable for the female pliers users. Application: The results of the study might help to reduce hand-related musculoskeletal disorders and perform efficient task in the real-work environment.

Optimal Grip Span of A-type Pliers in a Maximum Gripping Task

Yong-Ku Kong,Jin Woo Jung,Sangmin Kim,Heewoong Jung,Hakje Yoo,Dae-Min Kim,Hyun-Sung Kang 대한인간공학회 2013 大韓人間工學會誌 Vol.32 No.6

Objective: The objective of this study is designing an optimal hand tool through maximum grip force study accordance to the hand grip span. Background: In order to prevent musculoskeletal diseases, studies on hand tool design are proceeding based on grip strength, finger force, and contribution of individual finger force on total grip strength. However, experimental apparatus using a tool that is actually used in work place was almost non-existent. Method: 19 males were participated in an experiment. Using the load cell inserted real plier, finger force, grip strength, and subjective discomfort rate of both hands (dominant and non-dominant) were measured in 5 different hand grip span(45mm, 50mm, 60mm, 70mm, and 80mm). Results: There was significant difference(p<0.001) of total grip strength, individual finger force and subjective discomfort rating according to various hand grip span(45, 50, 60, 70, and 80mm). Also, statistically significant different(p<0.001) was shown between the dominant hand and non-dominant hand. In addition, individual finger force in maximum grip was in order of middle finger, ring finger, index finger, and little finger. Conclusion: Optimal grip span of pliers that exerting maximum grip strength is 50~60mm. Application: This finding is expected to be used for designing proper pliers.

손잡이가 휜 Plier의 작업 수행도, 손목 동작과 만족도 평가

기도형(Dohyung Kee) 대한인간공학회 2008 大韓人間工學會誌 Vol.27 No.2

This study aims to investigate the effect of handle angles of pliers on performance, wrist motion and subjective rating of satisfaction. An experiment was conducted, in which handle angle of pliers was used as independent variable and 14 subjects participated. Based on the literature survey, plier handles angled at 0°, 10°, 20°, 30° and 40° were adopted in the experiment. The subjects were instructed to bend iron plates by 90° and to cut wires as soon as possible. The results revealed that 1) handle angles of pliers have significant effect on wrist motion and satisfaction(p<0.0001); 2) handle angles of pliers did not affect performance of completing tasks irrespective of types of tasks done in the study; 3) in the initial stage of windup, plier with handle angled at 20° produced the least wrist motion of deviation in task of bending iron plates, while plier with handle angled at 40° did in task of cutting wires; 4) degree of satisfaction was maximized when handle of pliers was bent by 20° in both tasks. On the basis of the results, it is recommended that handle of pliers be bent by 20~30° for reducing musculoskeletal disorders related to pliers.

손잡이가 휜 Plier의 작업 수행도와 선호도 평가

기도형 ( Do Hyung Kee ) 한국안전학회 2008 한국안전학회지 Vol.23 No.1

품질기능전개를 이용한 플라이어의 인간공학적 디자인

박희석(Hee Sok Park),이미란(Mi Ran Lee) 대한인간공학회 2007 大韓人間工學會誌 Vol.26 No.4

This study shows a way to develop ergonomic design of a plier through quality function deployment (QFD) approach. User needs for pliers, as well as the engineering characteristics which have influence on the ergonomic quality of pliers were determined from the interviews and questionnaires with various user groups. This information was entered in the house of quality, and the results show that the handle is the most important quality factor. A new model was proposed in which ergonomic and gender aspects were considered. QFD is considered a suitable method especially for the manufacturing and/or design fields where biomechanical or physiological background is not present.

TMN 기반 RRSiM(Real Resource SiMulator)

진현준(Hyun-Joon Jin),송병권(Byung-Kwen Song) 호서대학교 공업기술연구소 2013 공업기술연구 논문집 Vol.32 No.2

본 논문에서는 실제자원의 개발 전에도 망관리 시스템의 개발 및 운용 테스트를 수행하도록 지원하는 실제 자원 시물레이터를 구현한다. 실제자원 시물레이터는 객체의 상태를 유지하는 관리객체 테이블과 사용자가 정의한 동작 특성을 유지하는 데이터 테이블, 랜덤(Random)값과 랜덤 주기 값을 발생할 지원 함수들, 순차적인 사건 발생 또는 값의 수정을 지원하는 스케줄링 테이블 그리고 이들을 전체적으로 관장하는 메인 커널로 이루어져 있다. 또한 사용자는 확장된 GDMO 문법을 이용하여 실제자원 시물레이터의 동작 특성을 지정할 수 있는데, 본 논문에서는 이를 처리할 확장된 GDMᄋ 컴파일러를 설명하고, 사용자와 실제자원 시물레이터간의 동작. 시물레이터와 에이전 트간 동작, 실제자원 시물레이터. 에이전트, 망관리 시스템으로 이루어진 환경에서의 동작 확인 결과를 보인다. in this paper, we propose a RRSiM (Real Resource SiMulator) that supports the development and operational test or network management system before the development o f real resources. The components o f the R R SiM are the Managed Object Table that holds the current status information o f real resources, the Simulation Data Table that holds the characteristics o f real resources defined by user, the support functions that generate the random values and random interval values, the scheduling table that holds the sequence o f events, and the m ain kernel. Users can set up behaviors o f the R R SiM by extended-GDMO description. W e present the structure o f our extended-GDMO compiler and activities o f RRSiM . W e also show the interaction between user and the RRS, interaction between the RR SiM and the agent, and interaction among the NM S, the agent and the RRSiM .