Quadriceps Femoris Group

Joe Muscolino

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Anterior and lateral views of the four muscles of the quadricep femoris group.

The Quadriceps Femoris Group is composed of:

  • Rectus Femoris
  • Vastus Lateralis
  • Vastus Medialis
  • Vastus Intermedius

 

ATTACHMENTS:

  • The quadriceps femoris group attaches from the AIIS of the pelvic bone and shaft of the femur to the patella and then via the [infra-]patella ligament onto the tibial tuberosity.
    • Only the rectus femoris crosses the hip joint to attach onto the pelvic bone.
    • The vastus muscles attach onto the shaft of the femur.
      • The vastus lateralis and intermedius onto the lateral lip of the linea aspera.
      • The vastus medialis onto the medial lip of the linea aspera.

 

ACTIONS:

  • Extends the leg (and/or thigh) at the knee joint (all four quads).
  • Flexes the thigh and anteriorly tilts the pelvis at the hip joint (rectus femoris only).
  • Tracks the patella at the patellofemoral joint.
    • Lateral tracking (vastus lateralis).
    • Medial tracking (vastus medialis).

 

NOTES:

  1. The quadriceps femoris group is thought of as being anterior in the thigh. Indeed, it is superficial anteriorly, but it also envelops nearly the entire femur, attaching around to the medial lip of the linea aspera on the medial side, and attaching around to the lateral lip of the linea aspera on the lateral side.
  2. Only the rectus femoris crosses the hip joint to attach onto the pelvic bone.
  3. All four quadriceps femoris muscles cross the knee joint.
  4. The vastus lateralis and vastus intermedius lie deep to the iliotibial band (ITB). Pain that is ascribed to the ITB is often generated in the vastus musculature instead.