Vastus muscles

Group of muscles in the thigh

The vastus muscles are a group of muscles located in the anterior compartment of the thigh. They are part of the quadriceps femoris muscle group, which is crucial for knee extension. The vastus muscles include the vastus lateralis, vastus medialis, vastus intermedius, and the vastus intermedius is sometimes considered to include the articularis genus.

Anatomy

The vastus muscles originate from the femur and insert into the patella via the quadriceps tendon. They are innervated by the femoral nerve and receive blood supply from the lateral circumflex femoral artery.

Vastus Lateralis

The vastus lateralis is the largest of the vastus muscles. It originates from the greater trochanter and the lateral lip of the linea aspera of the femur. It extends the knee and stabilizes the patella.

Vastus Medialis

The vastus medialis is located medially in the thigh. It originates from the intertrochanteric line and the medial lip of the linea aspera. It plays a key role in stabilizing the patella and extending the knee.

Vastus Intermedius

The vastus intermedius lies between the vastus lateralis and vastus medialis. It originates from the anterior and lateral surfaces of the femur. It is responsible for knee extension.

Function

The primary function of the vastus muscles is to extend the knee joint. This action is essential for activities such as walking, running, and jumping. The vastus medialis also helps in stabilizing the patella, preventing lateral displacement.

Clinical Significance

Injuries to the vastus muscles can result in pain and weakness in the knee. Conditions such as patellofemoral pain syndrome and quadriceps tendonitis are associated with dysfunction in these muscles. Strengthening exercises targeting the vastus muscles are often recommended in rehabilitation programs.

Images

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  Illustration of lower extremity muscles
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  Vastus lateralis muscle
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  Vastus medialis muscle
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  Vastus intermedius muscle
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  Muscles of the thigh
• Vastus muscles in dissection
  Vastus muscles in dissection
• Vastus lateralis in dissection
  Vastus lateralis in dissection
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  Vastus medialis in dissection
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  Vastus intermedius in dissection

Related Pages

• Quadriceps femoris
• Femoral nerve
• Knee joint

References

• Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2013). Clinically Oriented Anatomy. Lippincott Williams & Wilkins.
• Netter, F. H. (2014). Atlas of Human Anatomy. Elsevier Health Sciences.