The Study On The Relationship Between The Stiffness Of Muscle And Modified Ashworth Scale Using Shear Wave Elastography

ObjectiveTo investigate the Young’s modulus of the biceps brachii and brachialis and brachioradialis in the stroke patients with quantitative shear-wave ultrasound elasticity technique, and to observe the relationship between the stiffness of stroke-impaired muscle and Modified Ashworth Scale, analysis the correlation between the muscle stiffness and TCM Syndrome Typesand, to observe the value of shear-wave ultrasound in Quantifying the muscle spasm as a noninvasive examination method.MethodsShear wave ultrasound measurements were made at resting and passives stretching biceps brachii and brachialis and brachioradialis of the paret ic and non-paretic limbs of thirty-seven stroke survivors, which TCM diffe-rentiation was hyperactivity of yang due to yin deficiency or Phlegm and blood stasis blocking collaterals. Two rehabilitation physicians used the MAS to assess the muscle tone of the elbow flexors.Results1. The Young’s modulus in the paretic resting positions between the elbow three flexor muscles has no defference. The Young’s modulus in the passives stretching positions paretic brachialis were greater than biceps brachii(P <0.01) and brachioradialis (P<0.05). The stiffness of stroke-impaired muscle of biceps brachii were strongly correlated with the grade in Modified Ashworth Scale (P<0.05), so as brachialis and brachioradialis (P<0.001, P<0.01)2. The Young’s modulus’difference of biceps brachii between the resting and stretching on the paretic side were greater than on the contralateral non-paretic side(P<0.01), so as the brachialis (P<0.001) and brachioradialis (P<0.01), and the brachialis were the greatest among three muscles on the paretic side (P<0.001)3. The muscle stiffness between the elbow flexor muscles in the non-paretic in the resting positions were different.brachialis were greater than biceps brachii and brachioradialis (P<0.01), so as in the stretching positions (P <0.01). The Young’s modulus in paretic side was not correlated with either the Fugl-Meyer score or with age. Individuals with a longer duration since the stroke onset had greater in the Young’s modulus of brachioradialis (r 2=0.396, P<0.05). Individuals with greater BMI had smaller stiffness in the Young’s modulus of brachialis (r2=-0.438, P<0.05).The Young’s modulus in paretic side of biceps brachii between two the kinds of TCM differentiation was no difference, so as brachialis and brachioradialis(P>0.05).Conclusion:1. The muscle stiffness in the paretic resting positions between the elbow flexor muscles has no defference. But the muscle stiffness in the passives stretching paretic between muscles were different, brachialis were greater than biceps brachii and brachioradialis And the stiffness of stroke-impaired muscle of biceps brachii were strongly correlated with the grade in Modified Ashworth Scale, so as brachialis and brachioradialis. As the grade was higher in Modified Ashworth Scale, the stiffness was greater.2. The muscle stiffness have significant changes from the relaxation to unbend passive stretching process either on the paretic side or contralateral non-paretic side, but the paretic side changes were larger than the contralateral non-paretic side. And the brachialis were largest change among the elbow flexor muscles on the paretic side.3. The muscle stiffness between the elbow flexor muscles in the non-paretic in the resting positions were different, brachialis were greater than biceps brachii and brachioradialis, so as in the stretching positions. Individuals with a longer duration since the stroke onset had greater in the muscle stiffness of brachioradialis. Individuals with greater BMI had smaller stiffness in the Young’s modulus of brachialis. The Young’s modulus in paretic side of biceps brachii between two the kinds of TCM differentiation was no difference, so as brachialis and brachioradialis.