Design of optimum grip and control area for one-handed manual control devices

The objective of this paper was to make a design specification of the control area in dual tasks of the hand grip and manual control. The grip postures were analyzed for three types of hand tools. An experiment was performed to measure the position of the fingers and the maximum finger forces at 4 different postures for nine subjects. It was found out that the finger forces were significantly affected by the subjects, the fingers, and the grip postures. The maximum force of women was 62% of menʹs. From the experiment, the primary control area was defined as 10–13cm and the secondary control area as 8–12cm from the wrist origin. The preferred hand posture of the index and the middle fingers was found to be 3045 degrees at metacarpophalangeal joint and 4050 degrees at proximal interphalangeal joint. It was also found out that the design of one-handed manual control devices should include the characteristics of the user, grip posture, finger force, and the control arrangement.