A linear force-summing hand dynamometer independent of point of application.

Theory, design and construction details are presented for a versatile strain gauge hand dynamometer. What distinguishes this instrument is that sensitivity is completely independent of the location. Force is applied so it is capable of linearly summing forces exerted at multiple locations along the length of the active area of the dynamometer. In addition to including the basic principles of this transducer, a template for the instrument and an accompanying spread sheet is provided for computing transducer response characteristics for instruments of arbitrary size, including sensitivity and force range, depending on particular measurement requirements. Variations of this dynamometer were constructed and used for measuring grip and pinch strength, as well as for measuring submaximal exertions produced during manual activities and tasks. Because this dynamometer is compact and rigid, one of suitable dimensions may be substituted as a handle for tools or objects handled during work for directly measuring applied exertions and grip force. Examples of practical applications of this instrument are given for hand biomechanics, hand tool ergonomics, and clinical evaluations.