Thompson Brennan J, Xu Jennifer
Department of Kinesiology and Health Science, Utah State University, Logan, UT 84322, USA.
Movement Research Clinic, Sorenson Legacy Foundation Center for Clinical Excellence, Utah State University, Logan, UT 84322, USA.
J Funct Morphol Kinesiol. 2023 May 12;8(2):62. doi: 10.3390/jfmk8020062.
The reliability of isokinetic peak torque (PT) has been reported mostly using a short-term (<~10 day) inter-trial testing time frame. However, many studies and programs utilize a long-term (several weeks to months) inter-trial testing period. Additionally, the methods by which the PT value is selected and reported from a multiple rep testing scheme have not been well investigated for both reliability and PT absolute performance comparisons. The purpose of this study was to investigate the long-term reliability of isokinetic and isometric PT of the leg extensors with an emphasis on the differences among several PT score selection methods. Thirteen men and women (age = 19.5 years) underwent two testing trials separated by 28.8 (±1.8) days. Testing included maximal voluntary contractions of three sets of three reps for two isokinetic contraction conditions of 60 (Isok60) and 240 (Isok240) deg/s velocities, and three sets of one rep of isometric contractions for the leg extensors. The PT score was derived from seven different methods (see text for descriptions). Reliability as assessed from intraclass correlation coefficients (ICCs) varied widely across contraction conditions and PT score selection parameters. The Isok60 velocity overall had lower reliability (ICCs = 0.48-0.81) than Isok240 (0.77-0.87) across the conditions whereas the isometric PT variables showed moderate reliability (0.71-0.73). Overall the set 1 PT score selection parameters were generally lower ( ≤ 0.05) than those that involved sets two and three. Systematic error ( ≤ 0.05) was shown for 6 out of the 17 PT selection variables. On a subjective interpretation basis, when taking everything into account the best overall combination of time/trial efficiency, reliability, best/highest PT score parameter, and reduced risk of systematic bias appears to be the PT variable that uses the average of the highest two reps of the first two sets of three reps-i.e., averaging the highest two values of the six total reps from the first two sets.
等速峰值扭矩（PT）的可靠性大多是在短期（<约10天）的试验间测试时间框架内报告的。然而，许多研究和项目采用的是长期（数周至数月）的试验间测试期。此外，从多次重复测试方案中选择和报告PT值的方法，在可靠性和PT绝对性能比较方面都尚未得到充分研究。本研究的目的是调查腿部伸肌等速和等长PT的长期可靠性，重点是几种PT分数选择方法之间的差异。13名男性和女性（年龄 = 19.5岁）接受了两次测试，间隔28.8（±1.8）天。测试包括在60（Isok60）和240（Isok240）度/秒速度的两种等速收缩条件下进行三组，每组三次重复的最大自主收缩，以及腿部伸肌的三组，每组一次重复的等长收缩。PT分数来自七种不同的方法（描述见正文）。根据组内相关系数（ICC）评估的可靠性在不同收缩条件和PT分数选择参数之间差异很大。在所有条件下，Isok60速度的总体可靠性（ICC = 0.48 - 0.81）低于Isok240（0.77 - 0.87），而异长PT变量显示出中等可靠性（0.71 - 0.73）。总体而言，第一组PT分数选择参数通常低于（≤0.05）涉及第二组和第三组的参数。17个PT选择变量中有6个显示出系统误差（≤0.05）。基于主观解释，综合考虑所有因素，时间/试验效率、可靠性、最佳/最高PT分数参数以及系统偏差风险降低的最佳总体组合似乎是使用前三组中每组三次重复的最高两次重复的平均值的PT变量，即平均前两组总共六次重复中的最高两个值。
