Wachter N J, Mentzel M, Hütz R, Gülke J
Clinic for Hand-, Plastic and Microsurgery, Klinikum Stuttgart, Kriegsbergstrasse 60, 70174 Stuttgart, Germany.
Clinic for Traumatology, Hand-, Plastic and Reconstructive Surgery, University of Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
Hand Surg Rehabil. 2017 Apr;36(2):90-96. doi: 10.1016/j.hansur.2016.12.003. Epub 2017 Feb 7.
In the assessment of hand and upper limb function, detecting sincerity of effort (SOE) for grip strength is of major importance to identifying feigned loss of strength. Measuring maximal grip strength with a dynamometer is very common, often combined with calculating the coefficient of variation (CV), a measure of the variation over the three grip strength trials. Little data is available about the relevance of these measurements in patients with median nerve impairment due to the heterogeneity of patient groups. This study examined the reliability of grip strength tests as well as the CV to detect SOE in healthy subjects. The power distribution of the individual fingers and the thenar was taken into account. To assess reliability, the measurements were performed in subjects with a median nerve block to simulate a nerve injury. The ability of 21 healthy volunteers to exert maximal grip force and to deliberately exert half-maximal force to simulate reduced SOE in a power grip was examined using the Jamar dynamometer. The experiment was performed in a combined setting with and without median nerve block of the same subject. The force at the fingertips of digits 2-5 and at the thenar eminence was measured with a sensor glove with integrated pressure receptors. For each measurement, three trials were recorded subsequently and the mean and CV were calculated. When exerting submaximal force, the subjects reached 50-62% of maximal force, regardless of the median nerve block. The sensor glove revealed a significant reduction of force when exerting submaximal force (P1 sensor) with (P<0.032) and without median nerve block (P<0.017). An increase in CV at submaximal force was found, although it was not significant. SOE can be detected with the CV at the little finger at using a 10% cut-off (sensitivity 0.84 and 0.92 without and with median nerve block, respectively). These findings suggest low reliability of the power grip measurement with the Jamar dynamometer, as well as that of the CV for detecting SOE. However, the combination of finger forces including the thenar area and the CV at the little finger could lead to better reliability for detecting feigned reduction of grip strength. The methods were as reliable in subjects with a median nerve block as in healthy subjects.
在评估手部和上肢功能时，检测握力的用力真实性（SOE）对于识别假装的力量丧失至关重要。使用测力计测量最大握力非常常见，通常还会结合计算变异系数（CV），它是三次握力测试中变化程度的一种度量。由于患者群体的异质性，关于这些测量在正中神经损伤患者中的相关性的数据很少。本研究检验了握力测试以及CV在健康受试者中检测SOE的可靠性。研究考虑了各个手指和大鱼际的力量分布。为了评估可靠性，在接受正中神经阻滞的受试者中进行测量，以模拟神经损伤。使用Jamar测力计检查了21名健康志愿者在强力握力中施加最大握力以及故意施加半最大握力以模拟降低的SOE的能力。实验在同一受试者有和没有正中神经阻滞的组合情况下进行。使用带有集成压力感受器的传感器手套测量第2 - 5指指尖和大鱼际隆起处的力。每次测量随后记录三次试验，并计算平均值和CV。当施加次最大力时，无论正中神经阻滞情况如何，受试者达到最大力的50 - 62%。传感器手套显示，在施加次最大力时（P1传感器），有正中神经阻滞（P<0.032）和没有正中神经阻滞（P<0.017）时力均显著降低。发现次最大力时CV增加，尽管不显著。使用10%的临界值时，通过小指处的CV可以检测到SOE（分别在没有和有正中神经阻滞时，灵敏度为0.84和0.92）。这些发现表明，使用Jamar测力计进行强力握力测量以及使用CV检测SOE的可靠性较低。然而，包括大鱼际区域的手指力量与小指处的CV相结合，可能会在检测假装的握力降低方面具有更好的可靠性。这些方法在有正中神经阻滞的受试者中与在健康受试者中一样可靠。
