Muscle Thickness and Echo Intensity of the Abdominal and Lower Extremity Muscles in Stroke Survivors

BACKGROUND AND PURPOSE: This study compared the muscle thickness (MT) and echo intensity (EI) of the abdominal, thigh, and lower leg muscles between the paretic and nonparetic sides in chronic stroke survivors. METHODS: Thirty-two stroke survivors living in the community participated in this study. The MT and EI, which are indicators of muscle mass and intramuscular fat or connective tissue, were assessed in the rectus abdominis, external oblique, internal oblique, transversus abdominis, rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, tibialis anterior, gastrocnemius, and soleus via transverse ultrasound imaging. In addition, a possible indicator of physical activity—the frequency of going out per week—was evaluated. RESULTS: All quadriceps muscles and the tibialis anterior were significantly thinner and the EI values of the vastus intermedius, vastus lateralis, vastus medialis, and soleus were significantly higher in the paretic limb than the nonparetic limb. The MT and EI values of abdominal muscles did not differ significantly between the two sides. The MT values of the paretic rectus femoris, vastus lateralis, and vastus medialis were significantly associated with the frequency of going out after adjusting confounding factors. The MT of the nonparetic vastus lateralis was significantly associated with latency from stroke onset after adjusting confounding factors. CONCLUSIONS: Our results indicate that quantitative and qualitative changes on the paretic side in stroke survivors were the most robust in the thigh muscles, whereas such changes might not occur in the abdominal muscles.