| ObjectiveTo explore the intra-and inter-opertator test reliability of the patellar tendon and quadriceps femoris stiffness by shear wave elastography(SWE).To characterize the elastic modulus of static stretching(SS)of an individual muscle of the thigh.To campare the biomechanical characteristics of individual muscle of quadriceps and specific region of patellar tendon in different knee flexion angles.To observe the value of shear wave elastography in quantifying stiffness of muscle and tendon as a noninvasive measurement.MethodsFrom October to November,2017,the average stiffness of the patellar tendon and quadriceps femoris of 20 healthy men was assessed by SWE,and the repeated assessment were performed at five days later.The results were evaluated with interclass correlation coefficient(ICC).To campare the elastic modulus of the lateral femoris,rectus femoris and medial femoris before and after the stretch.With passive flexion to knee with a fixed respectively fixed at 30°,6° 0 and 90°.SWE(tissue elastic index)was measured by ultrasonic shear wave elastography in a relaxed(passive)state.Results1.The reliability was good in patellar tendon(ICC=0.79)both in intra-observer and inter-observer;medium in rectus femoris in intra-observer(ICC=0.71)and in inter-observer(ICC=0.73);good in vastus lateralis muscle in intra-observer(ICC=0.84)and medium in inter-observer(ICC=0.74);excellent in vastus medialis both in intra-observer(ICC=0.95)and inter-observer(ICC=0.94).2.The elastic modulus of thigh muscles decreased in the subjects after 1-min static stretching when compared with the controls(P<0.05).The decrease ratio from high to low was VL(25.5%)>RF(19.8%)>VM(12.5%).3.The rectus muscle and vastus lateralis muscles and shares the elastic modulus of the medial muscle in 30°,60 0 and 90° of knee joint when comparing all have significant difference(P<0.05),the lateral muscles and shares the elastic modulus of the medial muscle at 30 0 of knee joint contrast there were significant differences(P<0.05)in 60 0 and 90 0 contrast when there was no significant difference(P>0.05).4.In knee joint 30 °,60° and 90 °,the patellar tendon,modulus of elasticity of the different parts of the anterior and posterior comparison there was no significant difference(P>0.05).30 0 of knee joint,the patellar tendon proximal anterior compared to the middle of anterior and posterior,distal of anterior and posterior elastic modulus were significantly different(P<0.05)cut its elastic modulus is higher than other regions of the patellar tendon proximal of anterior and posterior elastic modulus compared with no significant difference(P>0.05);Knee 60 ° and 90 °,the patellar tendon proximal posterior compared to the distal of modulus of elasticity were significant differences(P<0.05),while the patellar tendon proximal anterior compared with elastic modulus of other levels had no significant difference(P>0.05).Conclusion1.This study showed that the quantitative evaluation of patellar tendon and quadriceps femoris muscle strength characteristics using shear wave ultrasound elastography showed good reliability between the same test subjects and different test subjects.It is a reliable and repeatable method to measure that stiffness of patellar tendon and femoral quadricep by the ultrasonic imaging technique of elastic shear wave.2.The study tested the effects of static stretching on individual muscle in the quadriceps femoris.It was observed that 1 minute static stretching enhanced the attenuation of the elastic modulus.In addition,different effects on individual muscles were observed after intervention.Researchers and clinicians should take this into account when statically stretching muscles.3.The different of quadriceps muscle and the patellar tendon proximal in knee joint passive buckling is greater than or equal to 30°.present different elastic properties.The correlation between the heterogeneity of this passive elastic property and the injury is still unknown. |
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