Bourbonnais Daniel, Frak Victor, Pilon Jean-François, Goyette Michel
Centre de recherche interdisciplinaire en réadaptation du Montréal métropolitain (CRIR), site Institut de réadaptation de Montréal, Montréal, QC, H3S 2J4, Canada.
J Neuroeng Rehabil. 2008 Jan 2;5:2. doi: 10.1186/1743-0003-5-2.
The function of a cylinder allowing simultaneous measurements of the opposition axis of the index finger and thumb of the hand and the magnitude of pinch force is described.
The apparatus is made of two half-cylinders that are bonded together through a 6-axis force/torque sensor and allows the measurement of 3D orthogonal forces and moments of force. The amplitude of the pinch force exerted on the cylinder by the fingers is defined as the resultant of the forces in the different axes. A software program was developed to measure the barycentre of the forces on the instrumented cylinder, allowing calculation of the angle of the opposition axis between the fingers and the location of the resulting pinch force on the cylinder, assuming that the pinch or grip forces are co-linear through the center of the cylinder. In order to assess the validity and reliability of the measurements, the cylinder was mounted on a milling table and seven calibrated weights (from 100 to 500 g) were successively applied perpendicularly to a 9*9 matrix of sites separated by 1 cm. With the exception of the extreme lateral parts of the cylinder, the dispersion of the calculated vertical position of the resulting force was always within 1 mm of the application point, suggesting a high reliability of these measurements. In addition, the errors in the angles of the applied force were calculated and found to be less than 2 degree with no clear patterns of variation across the different locations of the cylinder.
The usefulness of the cylinder is demonstrated by evaluating the pinch force and the opposition axis in six healthy subjects lifting the cylinder from the table using three different orientations of their right hand. The magnitude of the grip force was not significantly different across orientations (45, 22 and -22 degrees relative to the midline of the subject) suggesting that force grip is controlled.
From these results, it has been concluded that the cylinder is a valid, reliable and precise instrument that may prove useful for evaluating opposition axis and grip force in healthy and pathological populations.
描述了一种圆柱体的功能，该圆柱体可同时测量手部食指和拇指的对掌轴以及捏力大小。
该装置由两个半圆柱体组成，它们通过一个六轴力/扭矩传感器连接在一起，可测量三维正交力和力矩。手指施加在圆柱体上的捏力大小定义为不同轴向上力的合力。开发了一个软件程序来测量仪器化圆柱体上力的重心，假设捏力或握力通过圆柱体中心共线，从而计算手指之间对掌轴的角度以及圆柱体上产生的捏力位置。为了评估测量的有效性和可靠性，将圆柱体安装在铣床上，依次将七个校准重量（从100克到500克）垂直施加到一个9×9的矩阵位点上，位点间距为1厘米。除圆柱体的最外侧部分外，计算得到的合力垂直位置的分散度始终在施加点1毫米范围内，表明这些测量具有很高的可靠性。此外，计算了施加力角度的误差，发现误差小于2度，且在圆柱体的不同位置没有明显的变化模式。
通过评估六名健康受试者用右手的三种不同方向从桌子上拿起圆柱体时的捏力和对掌轴，证明了该圆柱体的实用性。不同方向（相对于受试者中线分别为45度、22度和 -22度）的握力大小没有显著差异，表明握力是可控的。
从这些结果可以得出结论，该圆柱体是一种有效、可靠且精确的仪器，可能对评估健康人群和病理人群的对掌轴和握力有用。
