Validity of the Dexter Evaluation System's Jamar dynamometer attachment for assessment of hand grip strength in a normal population

There are several instruments available to measure grip strength, but some instruments are costly, time-consuming to use, or have questionable reliability. The purpose of this study is to examine to concurrent validity of the Dexter Evaluation System with Jamar dynamometer attachment (Dexter) compared with reference-based criterion of the Jamar adjustable hand dynamometer (Jamar) for measurement of maximal hand grip strength among normal subjects. Sixty-two subjects between the ages of 20 and 50 years, who had no history of hand, arm, shoulder, or neck injuries, were tested with the Jamar in the second handle position and, during the same visit, with the Dexter in the identical position. The Jamar was found to be highly reliable (ICC [3,1] = 0.98) and valid (ICC (2,K) = 0.99) for measuring hand grip strength. In this study, the Dexter was shown to be valid when compared to the Jamar dynamometer for measuring hand grip strength.