Gutierrez Z, Shechtman O: Effectiveness of the five–handle position grip strength test in detecting sincerity of effort in men and women. Am J Phys Med Rehabil 2003;82:847–855.
The five–handle position (five-rung) test is used to determine sincerity of effort of grip strength. However, there is a controversy in the literature concerning its validity and effectiveness. The purpose of the study was to investigate whether test results are affected by the amount of strength exerted by the gripping hand and to determine the test’s effectiveness.
A total of 30 hand therapy patients performed the five-rung grip test both maximally and submaximally with both the injured and uninjured hands. The standard deviation across the five strength trials was used to measure the shape of the curve. Sensitivity and specificity values were calculated for each sex.
The repeated measures analyses of variance revealed that average strength and the standard deviation were greater for men than for women, for maximal effort than for submaximal effort, and for the injured hand in comparison with the healthy hand. The most optimal standard deviation cutoff value was 8.5 (sensitivity, 0.70; specificity, 0.83), and the proportional area under the receiver operator characteristic curve was greater for the men (89%) than for women (80%).
The shape of the curve generated by the five-rung test was strength dependent; thus, the test may yield biased results when assessing sincerity of effort in people with weakened hands. The five-rung test was less effective for women than for men. Thus, we recommend that the five-rung test not be used to detect sincerity of effort.