The vastus medialis muscle occupies the anteromedial surface of lower half of thigh. It is the shortest head of the quadriceps femoris and it is partially covered by the rectus femoris. It is made up of muscle fibers that are directed obliquely downwards and anteriorly.
The vastus medialis arises from the medial lip of linea aspera of femur. Then it runs dowards to be continuous with a wide tendon, which partly fuses with the common tendon of the quadriceps femoris and it partly inserted into the medial border of patella to form the medial retinaculum of the patella.
Action
Together with the other three muscles that constitute the quadriceps femoris, the vastus medialis muscle extends the leg, assisting in rising/lifting the body from a sitting position.
Innervation
It is innervated by nerve fibers arising from the femoral nerve (L2-L4)
Blood Supply
The vastus medialis muscle receives oxygenated blood from branches of the profunda femoris and the descending genicular artery.
