Vastus Intermedius

Some of the deeper fibres of vastus intermedius attach to the superior aspect of the suprapatellar bursa which lies underneath the muscle. These fibres are referred to as the articularis genus, and arise from a small area on the lower third of the anterior femoral shaft, passing downwards to the bursa. 

Vastus Intermedius is the hardest of the quadriceps muscles to stretch due to its position as the deepest and most central muscle. The other quadriceps muscles can be stretched by adding some bias to the stretch – rectus femoris by extending the hip and vastus lateralis and medialis by adding a sideways element to the stretch, usually through massage - vastus intermedialis is too deep to manipulate.

Function Of Vastus Intermedius

Vastus intermedius works with the other three quadriceps muscles to extend the knee and plays an important role in stepping activities e.g. stepping over objects and climbing stairs, as well as with squatting.

The main function of the articularis genus is to stop the synovial membrane from becoming trapped and interfering with normal knee movement.

Common Problems

The most common problems associated with vastus intermedius are:

• Muscle Tightness: Tightness in vastus intermedius can irritate the underlying supra patellar bursa, resulting in knee bursitis
• Muscle Strain: Over-stretching or overloading of vastus intermedius can cause a quads strain
• Muscle Weakness: weakness in vastus medialis can affect knee movement and function, resulting in anterior knee pain

If you have knee pain from a problem with vastus intermedius have a look at:

1. Knee Muscles: Find out more about the muscles that control the knee, how they work and what can go wrong, including the other quadriceps muscles
   
   
2. Quads Stretches: Includes simple tests to see if your muscles are tight and some great stretches to improve flexibility
   
   
3. Quads Strengthening: Simple exercises to strength vastus intermedius and the other quads muscles
   
   
4. Knee Strengthening Exercises: A whole range of exercises to strengthen all of the different knee muscles, ranging from beginners to advanced

Summary

Muscle Group: Vastus Intermedius is the deepest of the Quadriceps

Action: Straightens the knee (extension)

Origin: Anterior and lateral surfaces of the femoral shaft and lower part of the lateral intermuscular septum

Insertion: Attaches to the deep surface of the other quadriceps tendon, the base of the patella, suprapatellar bursa and the tibia via the patella tendon

Nerve Supply: Femoral nerve (L2, L3, L4)

Functional Activities: Stepping activities such as climbing stairs and squatting

AKA: Vastus Intermedialis

Other Knee Muscles

Page Last Updated: 11/23/21
Next Review Due: 11/23/23

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