Résumé :
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Communication n° 600. Introduction. Muscular architecture, characterized by fascicle length (FL), pennation angle (Pa), and muscle thickness (MT), can be studied in vivo by using ultrasonography. The parameters are determinant for muscle force exertion. However, to our knowledge, the reproducibility of ultrasonography measures has received little attention. Objectives. The aim of this study was to examine the reproducibility of architectural parameter estimation with ultrasonography for different conditions (angle joint and torque) by calculating the intra-class correlation coefficient (ICC). Moreover the Bland and Altman test was used in order to confirm the results obtained by ICC method. Methods. Ten men and nine women participated in the study. An ultrasonic apparatus (HDI 5000, USA, probe: 7.5 MHz) was used to take images at a middle part of the VL. Test-retest measurements were performed at 10° and 100° of knee flexion, at rest and at 40 % of MVC. Results. For (Pa) calculated from the deep aponeurosis ICC was between 0.64 and 0.92, and for (Pa) calculated from deep and superficial aponeuroses ICC was between 0.51 and 0.90. (Pa) was more reproducible at 10° (0.83< ICC< 0.92) than at 100° (0.51< ICC < 0.81). (MT) values obtained by the calculation of the average side-to-side were more reproducible (0.74< ICC <0.94) than those measured at the centre of the image (0.65< ICC< 0.90). ICC values for estimation of (FL) were comprised between 0.51 and 0.88. (Pa) increased between 100° and 10° (p< 0.001) at rest and during contraction. Moreover, contraction increased (Pa) only at 10° (p< 0.001). (FL) was higher at 100° than at 10° (p< 0.001). (FL) was decreased during contraction only at 10° (p< 0.001). The Bland and Altman test confirms the ICC results. Conclusion. It would be more accurate to measure pennation angle between fascicles and deep aponeurosis and estimate muscle thickness using average side-to-side measurements. A knee joint angle near full extension must be used for study muscular architecture with ultrasonography.
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