Its voluntary because you choose whether you can move it
The quadriceps femoris is the great extensor muscle of the knee joint. It has four components:rectus femoris (fusiform bipennate muscle)vastus lateralisvastus intermediusvastus medialis.The tendons of these four muscles unite to form the common tendon and it is inserted on the patella, also is inserted on the tibial tuberosity.
vastus medialis
Vastus Medialis
the quadriceps which are composed of the rectus femoris vastus lateralis vastus medialis and vastus intermedius.
It is the smallest and weakest of the four.
i think it is the vastus lateralis but im not sure
the muscles that extends the lower leg are vastus lateralis, vastus medialis and vastus intermedius. These muscles collectively make up the quadriceps..
Quadracep muscles: vastus lateralis, vastus medialis, vastus intermedialis, sartorius Non-quads: Biceps femoris
The vastus lateralis is one of the quadricep muscles. The quadriceps are comprised of the rectus femoris, vastus lateralis, vastus medialis and vastus intermedius. The vastus lateralis is in the anterior portion of the thigh and is lateral.
The vastus medialis is involved in leg extensions.
Rectus femoris Vastus medialis Vastus intermedialis Vastus lateralis Sartorius
Vastus medialis (a tear-shaped muscle right above your knee)