Detecting sincerity of effort when measuring grip strength.

The purpose of the present study was to determine whether sincere and faked grip strength measurements could be distinguished from one another by the patterns of measurements obtained for the five handle (hand size) positions of the Jamar dynamometer. Healthy subjects were instructed on different trials to give a sincere, maximal effort or to fake weakness of grip. Results were that the patterns did differ for sincere and fake trials, but not as strongly as expected. The recommendation is made that further research be done using patients with upper extremity injury.