Vastus intermedius
Musculus vastus intermedius
MuscularDeep musclesLegLeft and right
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- What it is
- Deepest head of the quadriceps, wrapped directly around the front and outer side of the femoral shaft beneath rectus femoris. It arises from the upper two-thirds of the anterior and lateral femur and inserts through the deep layer of the quadriceps tendon.
- Function
- Extends the knee.
- Size
- About 30 cm long, 1.5-2 cm thick.
- Clinical note
- A small slip (articularis genus) lifts the suprapatellar bursa during extension; a "dead leg" contusion crushes it against the femur and can lead to myositis ossificans.