RESUMO
The detection of feigned weakness in hand grip strength assessment is difficult. The authors review several proposed methods and their weaknesses. A comparison of unilateral testing and simultaneous bilateral testing with the Jamar dynamometer and the Baseline pinch gauge is demonstrated as a solution. An experiment involved 100 asymptomatic subjects who were tested twice, once under instructions to give a full effort and once under instructions to feign weakness. Seven statistical criteria of noncompliance were chosen. Defining noncompliance as failing two or more of the seven criteria, 99% of the instructed noncompliant subjects were correctly classified as noncompliant. No subjects were incorrectly classified as noncompliant during instructed compliant testing. Twelve subjects failed on a single criterion. On retesting, all but one were correctly classified. One subject in the instructed noncompliant group passed all criteria. Accuracy was 99.5%, including retesting of the 12 "gray-zone" subjects.