Krishnan Chandramouli, Williams Glenn N
1Department of Physical Medicine & Rehabilitation, University of Michigan, Ann Arbor, Michigan; 2Department of Physical Therapy & Rehabilitation Science, University of Iowa, Iowa City, Iowa; and 3University of Iowa Sports Medicine Center, Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa.
J Strength Cond Res. 2014 Oct;28(10):2981-7. doi: 10.1519/JSC.0000000000000476.
Isometric knee extensor and flexor strength are typically tested at different joint angles due to the differences in length-tension relationships of the quadriceps and hamstring muscles. The efficiency of strength testing can be improved if the same angle can be used to test both the knee extensor and flexor muscle groups. The aim of this study was to determine an optimal angle for isometric knee strength testing by examining the effect of knee angle on side-to-side peak torque ratios. Eighteen active young people (9 males and 9 females) participated in this study. Knee extensor and knee flexor strength were tested on both sides at 30°, 60°, and 90° of knee flexion. The effect of knee flexion angle on side-to-side peak torque ratios, raw torque values, and side-to-side flexor-to-extensor torque ratios were assessed. Side-to-side knee extensor peak torque ratios and knee flexor-to-extensor torque ratios differed significantly by knee flexion angle (p = 0.024 and p = 0.011, respectively), but side-to-side knee flexor peak torque ratios did not differ significantly (p = 0.311). When considering both side-to-side peak torque ratios and flexor-to-extensor torque ratios, the values were more symmetrical (i.e., closer to 100%) only at 60° of knee flexion. Our results indicate that both the knee flexors and the knee extensors can be tested clinically at 60° of knee flexion. Our results also indicate that the hamstrings can be tested at any of the 3 angles if the examiner is interested in side-to-side ratios rather than raw torque values. These results may facilitate more efficient and flexible clinical knee strength testing.
由于股四头肌和腘绳肌的长度-张力关系不同，等长膝关节伸肌和屈肌力量通常在不同的关节角度进行测试。如果能使用相同的角度来测试膝关节伸肌和屈肌两组肌肉，力量测试的效率可以得到提高。本研究的目的是通过检查膝关节角度对左右侧峰值扭矩比的影响，确定等长膝关节力量测试的最佳角度。18名活跃的年轻人（9名男性和9名女性）参与了本研究。在膝关节屈曲30°、60°和90°时对双侧的膝关节伸肌和屈肌力量进行了测试。评估了膝关节屈曲角度对左右侧峰值扭矩比、原始扭矩值以及左右侧屈肌与伸肌扭矩比的影响。左右侧膝关节伸肌峰值扭矩比和膝关节屈肌与伸肌扭矩比因膝关节屈曲角度而有显著差异（分别为p = 0.024和p = 0.011），但左右侧膝关节屈肌峰值扭矩比没有显著差异（p = 0.311）。当同时考虑左右侧峰值扭矩比和屈肌与伸肌扭矩比时，仅在膝关节屈曲60°时这些值更对称（即更接近100%）。我们的结果表明，膝关节屈肌和伸肌都可以在膝关节屈曲60°时进行临床测试。我们的结果还表明，如果检查者对左右侧比值而非原始扭矩值感兴趣，腘绳肌可以在这三个角度中的任何一个进行测试。这些结果可能有助于更高效、灵活地进行临床膝关节力量测试。
