Identification of low-effort patients through dynamometry.

In recent years researchers have devised a number of methods to detect patients who purposely exert low effort during grip evaluations. This study further defines the five-rung grip test introduced by Stokes and subsequently challenged by Niebuhr and Marion. New data are presented on the rapid exchange grip test. Data were collected on four groups of subjects (sincere normals, normals asked to feign weak grip, patients thought to be sincere, and patients suspected of low effort) using both tests. In calculating the standard deviation of the plotted line of the five-rung grip test, group membership (sincere or low effort) can be predicted. No statistical difference between peak scores on five-rung and rapid exchange grip tests in sincere subjects was found. A statistical difference between peak scores in the low-effort groups was shown. A model has been developed that can be used to categorize patients into low effort or sincere groups.