McGarvey S R, Morrey B F, Askew L J, An K N
Clin Orthop Relat Res. 1984 May(185):301-5.
Isometric strength measurements of grip, pronation, supination, and elbow extension and flexion on dominant and nondominant sides were made on 40 normal subjects (age range, 40-70 years) to investigate the variability of isometric strength at different times of the day. Statistically significant differences were found in certain pronation, supination, and grip comparisons. No statistically significant difference was found in extension and flexion. Although significant, the absolute change in strength at different times of the day was small and showed no consistent trend. On the basis of these data, it appears that this variation can probably not be routinely detected in the normal clinical setting. However, the study further defines the reliability of isometric strength testing and should be considered in further attempts at more accurate measurement of elbow function. The small variations of strength, approximately 5%, that can be measured universally with sensitive testing equipment, are clinically relevant. However, when attempting to determine an impairment state in order not to place too much importance on small differences, care should be exercised in interpreting strength measurements. This investigation demonstrates how the application of sophisticated biomechanical techniques may be employed to provide useful objective information in the difficult clinical area of disability assessment. Disability judgments may be made more accurate as more is learned of the normal variables influencing objective measurement.
对40名正常受试者（年龄范围40 - 70岁）的优势侧和非优势侧进行了握力、旋前、旋后以及肘部伸展和屈曲的等长力量测量，以研究一天中不同时间等长力量的变异性。在某些旋前、旋后和握力比较中发现了统计学上的显著差异。在伸展和屈曲方面未发现统计学上的显著差异。尽管存在显著差异，但一天中不同时间力量的绝对变化很小，且没有一致的趋势。基于这些数据，在正常临床环境中似乎可能无法常规检测到这种变化。然而，该研究进一步明确了等长力量测试的可靠性，在进一步尝试更准确地测量肘部功能时应予以考虑。通过灵敏的测试设备普遍可测量到的约5%的力量小变化具有临床相关性。然而，在试图确定损伤状态时，为了不过度重视小差异，在解释力量测量结果时应谨慎。这项研究表明，如何应用复杂的生物力学技术在残疾评估这一困难的临床领域提供有用的客观信息。随着更多关于影响客观测量的正常变量的了解，残疾判断可能会更准确。
