Design of a Custom Force Fixture Fitting Miniature Load Cells for Individual Finger Force Measurement

Abstract

This research aims to address limitations of current hand grip measurement techniques by designing, building, and testing a more robust cylindrical dynamometer capable of measuring orthogonal force components while accounting for forces exerted by individual finger segments. The novel grip fixture consists of three static beams instrumented with strain gauges measuring orthogonal forces and eight attached miniature compensating load cells accounting for force contribution from finger segments. Following device fabrication and calibration, data was validated in a pilot study (n=6) where grip strengths were compared between the custom fixture and a Jamar dynamometer. Data suggests the custom dynamometer provides hand grip strength measurement comparable to that produced on a traditional dynamometer (p > 0.05). Future research studies using a similar device can guide therapy for patients with impaired hand strength by providing clinical professionals with a more complete profile of the forces exerted by hand segments.