Ruschel Caroline, Haupenthal Alessandro, Jacomel Gabriel Fernandes, Fontana Heiliane de Brito, Santos Daniela Pacheco dos, Scoz Robson Dias, Roesler Helio
Center of Health and Sports Sciences, University of the State of Santa Catarina, Florianópolis, Brazil.
J Sport Rehabil. 2015 May 20;24(2). doi: 10.1123/jsr.2013-0122. Print 2015 May 1.
Isometric muscle strength of knee extensors has been assessed for estimating performance, evaluating progress during physical training, and investigating the relationship between isometric and dynamic/functional performance.
To assess the validity and reliability of an adapted leg-extension machine for measuring isometric knee extensor force.
Validity (concurrent approach) and reliability (test and test-retest approach) study.
University laboratory.
70 healthy men and women aged between 20 and 30 y (39 in the validity study and 31 in the reliability study).
Intraclass correlation coefficient (ICC) values calculated for the maximum voluntary isometric torque of knee extensors at 30°, 60°, and 90°, measured with the prototype and with an isokinetic dynamometer (ICC2,1, validity study) and measured with the prototype in test and retest sessions, scheduled from 48 h to 72 h apart (ICC1,1, reliability study).
In the validity analysis, the prototype showed good agreement for measurements at 30° (ICC2,1 = .75, SEM = 18.2 Nm) and excellent agreement for measurements at 60° (ICC2,1 = .93, SEM = 9.6 Nm) and at 90° (ICC2,1 = .94, SEM = 8.9 Nm). Regarding the reliability analysis, between-days' ICC1,1 were good to excellent, ranging from .88 to .93. Standard error of measurement and minimal detectable difference based on test-retest ranged from 11.7 Nm to 18.1 Nm and 32.5 Nm to 50.1 Nm, respectively, for the 3 analyzed knee angles.
The analysis of validity and repeatability of the prototype for measuring isometric muscle strength has shown to be good or excellent, depending on the knee joint angle analyzed. The new instrument, which presents a relative low cost and easiness of transportation when compared with an isokinetic dynamometer, is valid and provides consistent data concerning isometric strength of knee extensors and, for this reason, can be used for practical, clinical, and research purposes.
已对等长伸膝肌力进行评估，以估计运动表现、评估体育训练过程中的进展情况，以及研究等长肌力与动态/功能表现之间的关系。
评估一种改良的腿部伸展器械测量等长伸膝力的有效性和可靠性。
有效性（同时性方法）和可靠性（测试及重测方法）研究。
大学实验室。
70名年龄在20至30岁之间的健康男性和女性（有效性研究中39名，可靠性研究中31名）。
计算在30°、60°和90°时伸膝肌最大自主等长扭矩的组内相关系数（ICC）值，使用原型器械和等速测力计进行测量（ICC2,1，有效性研究），以及在间隔48至72小时安排的测试和重测环节中使用原型器械进行测量（ICC1,1，可靠性研究）。
在有效性分析中，原型器械在30°测量时显示出良好的一致性（ICC2,1 = 0.75，标准误 = 18.2 Nm），在60°（ICC2,1 = 0.93，标准误 = 9.6 Nm）和90°（ICC2,1 = 0.94，标准误 = 8.9 Nm）测量时显示出极佳的一致性。关于可靠性分析，日间ICC1,1良好至极佳，范围为0.88至0.93。对于3个分析的膝关节角度，基于重测的测量标准误和最小可检测差异分别为11.7 Nm至18.1 Nm和32.5 Nm至50.1 Nm。
对测量等长肌力的原型器械的有效性和可重复性分析表明，根据所分析的膝关节角度，结果良好或极佳。与等速测力计相比，这种新器械成本相对较低且便于运输，是有效的，并能提供关于伸膝肌等长肌力的一致数据，因此可用于实际、临床和研究目的。
