Clockwise and Counter-Clockwise Torsion in Different Operational Angles on Transverse Plane
Working surface are usually set in the transverse plane. Most of hand tools are used in the working surface. The hand tools design affects the convenience and safety of human use. The wrenches are one of the most frequently used hand tools. To provide reference for the hand tools design, this study surveyed the two torque in five operational angles in transverse plane when use wrenches. Eighty volunteer adults (half male and half female) were recruited as subjects. The maximum torques of dominant hand were measured. Palm facing to ground is defined as 0°. Hand in supine positions are defined as positive angle and in prone positions are defined as negative angle. The five angles are: 0, 15, 22.5, 30, and 45°. The two torque are: clockwise and counter clockwise in horizontal plane. A digital torque wrench was used as the measurement apparatus. The results shown that the torque of counter-clockwise is greater than of clockwise in the horizontal plane. The torques forces in positive angles were greater than that in the negative angles. The torque forces of male is greater than that of female. The results of the study can be reference for research and other hand tools design.
KeywordsMuscle strength Torque force Anthropometry
This work was financially supported by the “Intelligent Recognition Industry Service Center” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan.
The authors thank the research group of Ergonomic Design at NYUST supported by Ministry of Science and Technology of Republic of China under project No. 106-2221-E-224-027 and No. 105-2410-H-224-021.
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