Ultrasound Imaging of the Vastus Intermedius and Vastus Medialis Oblique Thickness for Assessment of Early Torque Development During Knee Extension

Abstract

The purpose of this study was to investigate relationships between knee extension torque (rate of torque development and peak torque) and quadriceps muscle thickness in healthy males and females. Thirty-six recreationally active and healthy individuals participated in the study. Portable ultrasound was used to image the dominant side of each quadriceps muscle (rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, vastus medialis oblique). After muscle thickness measurement, participants performed knee extension maximal voluntary isometric contraction. Rate of torque development was calculated from 0 to 50 (RTD50) and 0 to 200 (RTD200) milliseconds after onset of torque generation and peak torque was defined as maximum torque during maximal voluntary isometric contraction trials. A higher RTD50 value was found to be associated with greater vastus intermedius and vastus medialis oblique thicknesses, and a higher RTD200 with the thickness of all quadriceps muscles (p < 0.05). Finally, vastus medialis and vastus medialis oblique thicknesses were associated with a higher peak torque (p < 0.05). According to these results, the findings suggest to coaches that vastus intermedius and vastus medialis oblique thicknesses are critical to torque development during the early phase of knee extension contraction (RTD50), which is essential for executing athletic tasks and preventing injuries.