Rapid repeat testing of grip strength for detection of faked hand weakness.

This study assessed the use of rapid, repeated measurement of grip strength to detect feigned hand weakness. Normal participants, performing with maximum effort or feigning hand weakness, and patients recovering from carpal tunnel surgery were asked to grip a Jamar dynamometer alternately with each hand on ten occasions. The results showed that grip strength fatigued by an average of 23% during the test in the normal participants, 18% in participants faking weakness, and increased by 2% in the carpal tunnel decompression patients. An increase in grip strength after the first effort was found in 39% of normal participants, 52% of participants faking hand weakness and in 69% of the carpal tunnel decompression patients. These results suggest that rapid, repeated measurement of grip strength is not a reliable discriminator of true and faked hand weakness.