Vastus lateralis: Found on the outer side of your thigh, it assists in knee extension. Vastus intermedius: Nestled between the vastus lateralis and vastus medialis, it also aids in knee extension.

of the vastus lateralis (VL) was measured under passive (resting) and active (contracting the knee extensors at 50% of maximal voluntary contraction) conditions, by using ultrasound shear wave ...