Simultaneous bilateral testing: validation of a new protocol to detect insincere effort during grip and pinch strength testing

J Hand Ther. Jul-Sep 2002;15(3):242-50. doi: 10.1016/s0894-1130(02)70007-0.


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.

Publication types

  • Comparative Study
  • Validation Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Female
  • Hand Strength / physiology*
  • Humans
  • Male
  • Malingering / diagnosis*
  • Middle Aged
  • Muscle Weakness / diagnosis
  • Patient Compliance
  • Reference Values
  • Sensitivity and Specificity