Quadriceps

Quadriceps

The Quadriceps (or Quadriceps femoris) is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the great extensor muscle of the knee, forming a large fleshy mass which covers the front and sides of the femur.

Anatomy

The name "quadriceps" is derived from Latin, meaning "four headed," as the group contains four separate muscles: the vastus lateralis, vastus medialis, vastus intermedius, and the rectus femoris. Each of these muscles originates on the femur and attaches to the patella. They are responsible for the extension of the knee, as well as assisting in hip flexion.

Vastus Lateralis

The Vastus lateralis is the largest and most powerful part of the quadriceps femoris. It extends the length of the thigh on the lateral side, and is responsible for extending and stabilizing the knee.

Vastus Medialis

The Vastus medialis originates on the femur and extends to the inner part of the knee, playing a crucial role in its extension.

Vastus Intermedius

The Vastus intermedius lies between the vastus lateralis and vastus medialis on the front of the femur, but deep to the rectus femoris. It is the most difficult part of the quadriceps to train individually.

Rectus Femoris

The Rectus femoris is situated in the middle of the front of the thigh; it is fusiform in shape, and its superficial fibers are arranged in a bipenniform manner, with a narrow tendon on either side. The deep fibers of the rectus femoris form a fusiform belly, which is situated at the upper part of the muscle.

Function

The quadriceps play a crucial role in walking, running, jumping and squatting. Because the rectus femoris attaches to the ilium, it is also a hip flexor. This action is also crucial to walking or running as it swings the leg forward into the ensuing step.

Clinical significance

Injury to the quadriceps muscle typically results from sports injuries or falls. Symptoms can include pain, swelling, and loss of function. Treatment typically involves rest, ice, compression, and elevation (RICE). In severe cases, surgery may be required.

See also

• Hamstring
• Knee
• Thigh

References

<references />

• Quadriceps 3D
  Quadriceps 3D
• Quadriceps
  Quadriceps
• Leg Extension Machine Exercise
  Leg Extension Machine Exercise
• Knee Diagram
  Knee Diagram
• 
  Gray's Anatomy - Quadriceps
• Gray's Anatomy - Knee
  Gray's Anatomy - Knee