Fig. 2

Muscle thickness* and pennate angle** measurements. a D1: Rectus femoris muscle thickness, D2: Vastus intermedius muscle thickness, b α: Rectus femoris pennate angle, c D3: Vastus medialis muscle thickness d α: Vastus medialis pennate angle *Muscle thickness: Distance between superficial and deep aponeurosis by holding the ultrasound probe axially and pressing it to the maximum, **Pennate angle: the angle formed at the attachment (with its insertion) of the muscle fascicles to the deep aponeurosis