Mayer T, Gatchel R, Betancur J, Bovasso E
Department of Orthopedic Surgery, University of Texas Southwestern Medical Center at Dallas, USA.
Spine (Phila Pa 1976). 1995 Apr 15;20(8):920-6; discussion 926-7.
This cohort study examined a sample (n = 152) of subjects tested for isokinetic lumbar strength and endurance, using novel endurance measures.
To validate a new lumbar sagittal isokinetic endurance testing protocol comparing reliability in a normal subject cohort with strength test reliability to include presentation of a gender-specific normative database, and then correlating the results to a Sorenson isometric endurance protocol.
The isometric Sorenson test has been virtually the only validated clinical tool for lumbar extensor trunk muscle endurance testing, using an exercise chair and permitting the subject to maintain the trunk horizontal against gravity for a single timed contraction. Alternative isokinetic sagittal lumbar performance measurement methodology has been developed recently to measure trunk muscle endurance by determining declining work performance on repeated, reciprocal dynamic contractions.
We compared protocols, performance measures, normative data, and reliability for the static isometric Sorenson test to three different isokinetic endurance measurements: the endurance ratio, final fatigue ratio, and recovery ratio. Subjects were tested on a sagittal Cybex TEF (Lumex, Inc., Ronkonkoma, NY) unit for a strength trial followed by an endurance trial. Subgroups also performed reliability and isometric endurance protocols.
We found an extremely low test-retest correlation for the isometric Sorenson trunk extension test. All test-retest correlations for the corresponding isokinetic endurance measures were significant and markedly higher. Extensor muscle performance declined more substantially on all endurance measures than flexors and showed more variability. In contrast, trunk strength measures were more reliable and less variable than corresponding endurance measures. Moreover, correlations between the isometric Sorenson test and the isokinetic endurance measures were all negative; i.e., increases in Sorenson time are moderately correlated to greater decline in work performance.
Reliability of the Sorenson isometric endurance test is unacceptably low, showing negative correlations to all isokinetic endurance tests for lumbar extensors. Isokinetic strength and endurance tests are far more reliable than isometric tests, with normative data showing more consistent results from men than women. Both genders display more substantial fatigue (and greater variability) in extensor endurance compared with flexor testing. Endurance measures are identified as human performance cognitive constructs, and reasons for greater variability than usually shown by trunk strength measurements are discussed.
这项队列研究使用新的耐力测量方法，对152名接受等速腰椎力量和耐力测试的受试者样本进行了检查。
验证一种新的腰椎矢状面等速耐力测试方案，比较其在正常受试者队列中的可靠性与力量测试的可靠性，包括呈现特定性别的标准数据库，然后将结果与索伦森等长耐力方案进行关联。
等长索伦森测试实际上一直是用于腰椎伸肌躯干肌肉耐力测试的唯一经过验证的临床工具，该测试使用一把运动椅，让受试者在重力作用下保持躯干水平进行单次定时收缩。最近开发了替代的等速矢状面腰椎性能测量方法，通过确定重复、往复动态收缩时工作性能的下降来测量躯干肌肉耐力。
我们将静态等长索伦森测试的方案、性能测量、标准数据和可靠性与三种不同的等速耐力测量方法进行了比较：耐力比率、最终疲劳比率和恢复比率。受试者在矢状面Cybex TEF（Lumex公司，纽约州罗恩科马）设备上先进行力量测试，然后进行耐力测试。各亚组还进行了可靠性和等长耐力测试方案。
我们发现等长索伦森躯干伸展测试的重测相关性极低。相应等速耐力测量的所有重测相关性均显著且明显更高。在所有耐力测量中，伸肌的性能下降比屈肌更显著，且变异性更大。相比之下，躯干力量测量比相应的耐力测量更可靠且变异性更小。此外，等长索伦森测试与等速耐力测量之间的相关性均为负；即，索伦森时间的增加与工作性能的更大下降呈中度相关。
索伦森等长耐力测试的可靠性低得令人无法接受，与所有腰椎伸肌的等速耐力测试均呈负相关。等速力量和耐力测试比等长测试可靠得多，标准数据显示男性的结果比女性更一致。与屈肌测试相比，两性在伸肌耐力方面都表现出更显著的疲劳（和更大的变异性）。耐力测量被确定为人类性能认知结构，并讨论了其变异性比通常躯干力量测量更大的原因。
