Abstract
Pinch strength is the muscular strength exerted by the fingertips when an object is grasped between two fingers. Since daily work provides many instances in which the hands are used, decreased pinch strength can be considered a symptom of fatigue. This paper describes the development of a portable pinch strength dynamometer. It can be used during a short break while on the job, driving a car, and so on. Two boards with an air chamber sandwiched in between them are pinched between two fingers, and a gauge measures the pressure inside the air chamber. An examination of the device's accuracy showed that it is able to produce accurate pinch strength measurements. The following two experiments were conducted.
1. To measure the pinch strength of a driver and fellow passengers of a car, and the rider of a motorcycle during short breaks while coming and going on a 2000 km trip.
2. To measure the pinch strength of 14 workers in a watch assembly plant during working hours for one week including a holiday.
With these data, the measurement of the physical and mental work load and fatigue by the dynamometer is expected.
