vastus medialis
noun
vastus me·di·a·lis
| \ -ˌmēd-ē-ˈā-ləs
, -ˈal-əs
\
, -ˈal-əs
\
Medical Definition of vastus medialis
: the division of the quadriceps muscle that covers the inner anterior aspect of the femur, arises chiefly from the femur and the adjacent intermuscular septum, inserts into the inner border of the patella and into the tendon of the other divisions of the muscle, sends also a tendinous expansion to the capsule of the knee joint, and is closely and in the upper part often inseparably united with the vastus intermedius
— called also vastus internus