Accuracy of Spring and Strain Gauge Hand-held Dynamometers

J Orthop Sports Phys Ther. 1989;10(8):323-5. doi: 10.2519/jospt.1989.10.8.323.


The accuracy of two spring gauge and two strain gauge hand-held dynamometers was determined using certified weights. Each dynamometer, which had extensive prior use, was vertically loaded with the certified weights in 5 lb increments from 5-55 lbs. Analysis of variance was used to compare the actual certified weights with the weights measured by each dynamometer. Additionally, Pearson product moment correlations were calculated between the weights measured by each device. The two spring gauge dynamometers measured comparably as did the two strain gauge dynamometers. Only the two strain gauge dynamometers, however, registered (measured) weights not differing significantly from the actual weights with which they were loaded. The correlations between each device's measurements were 0.98 or above. If the dynamometers tested are indicative, strain gauge dynamometers may be more accurate than spring gauge dynamometers after extensive use. J Orthop Sports Phys Ther 1989;10(8):323-325.