VASTUS MEDIALIS

Vastus medialis
Vastus medialis
Muscles of lower extremity
Latin	Musculus vastus medialis or musculus vastus internus
Gray's	p.471
Origin	Medial side of femur
Insertion	Quadriceps tendon
Artery	Femoral artery
Nerve	Femoral nerve
Actions	Extends leg
Dorlands /Elsevier	Vastus medialis muscle

The vastus medialis (vastus internus or teardrop muscle) is muscle located medially in the thighthat extends the knee. The vastus medialis is part of the quadriceps muscle.

Function

The Vastus Medialis is one of five muscles that reside in the . The vasti muscles appear to act largely in a co-ordinated manner throughout the control of knee extension. The vastus medialis contributes to correct tracking of the patella and characteristics of the vastus medialis, including its angle of insertion, correlate with presence of patellofemoral joint pain However, this syndrome is complex and definitive evidence of causality has not yet been published.

anterior compartment of the thigh

A division of the vastus medialis muscle into two populations of fibers has been hypothesized:

1. one population is thought to be long and relatively inline with the quadriceps ligament: the vastus medialis longus (VML)
2. the other is thought to be shorter and more obliquely oriented with respect to the quadriceps ligament: the vastus medialis obliquus (VMO).

At the present time, there is insufficient evidence to conclusively confirm or deny this hypothesis^] For clinical and rehabilitation purposes, the vastus medialis is often referred to simply as the VMO in reference to its potentially important role in correct patellar tracking and prevention of patellofemoral joint syndrome.

Origin and insertion

The Vastus Medialis muscle originates from a continuous line of attachment on the femur, which begins on the front and middle side (anteromedially) on the intertrochanteric line of the femur. It continues down and back (posteroinferiorly) along the pectineal line and then descends along the inner (medial) lip of the linea aspera and onto the medial supracondylar line of the femur. The fibers converge onto the inner (medial) part of the quadriceps femoris tendon and the inner (medial) border of the patella.