Quadriceps femoris muscle

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Quadriceps femoris muscle
Illu lower extremity muscles.jpg
Muscles of lower extremity. (Rectus femoris removed to reveal the vastus intermedius.)
Latinmusculus quadriceps femoris
Gray'ssubject #128 470
Origincombined rectus femoris and vastus muscles
Insertion   tibial tuberosity
Arteryfemoral artery
NerveFemoral nerve
ActionsKnee extension; Hip flexion (R.Fem. only)
Dorlands
/Elsevier
Quadriceps femoris muscle
 
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Quadriceps femoris muscle
Illu lower extremity muscles.jpg
Muscles of lower extremity. (Rectus femoris removed to reveal the vastus intermedius.)
Latinmusculus quadriceps femoris
Gray'ssubject #128 470
Origincombined rectus femoris and vastus muscles
Insertion   tibial tuberosity
Arteryfemoral artery
NerveFemoral nerve
ActionsKnee extension; Hip flexion (R.Fem. only)
Dorlands
/Elsevier
Quadriceps femoris muscle

The quadriceps femoris (/ˈkwɒdrɨsɛps ˈfɛmərɨs/) (Latin for "four-headed muscle of the femur"), also called simply the quadriceps, quadriceps extensor, quads, 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. The proper Latin plural form of the adjective quadriceps would be quadricipites. In modern English usage, quadriceps is used in both singular and plural. The singular form quadricep, produced by back-formation, is frequently used.

Portions[edit]

It is subdivided into four separate portions or 'heads', which have received distinctive names:

All four parts of the quadriceps muscle ultimately insert into the tibial tuberosity of the tibia. This is via the patella, where the quadriceps tendon becomes the patellar ligament, which then attaches to the tibia.

There is a fifth muscle of the quadriceps complex that is often forgotten and rarely taught called articularis genu.

Actions[edit]

All four quadriceps are powerful extensors of the knee joint. They are crucial in walking, running, jumping and squatting. Because rectus femoris attaches to the ilium, it is also a flexor of the hip. This action is also crucial to walking or running as it swings the leg forward into the ensuing step. The quadriceps, specifically the vastus medialis, plays the important role of stabilizing the patella and the knee joint during gait.[1]

Innervation[edit]

Femoral nerve (L2, L3, L4).

Training[edit]

In strength training, the quadriceps are trained by several leg exercises. Effective exercises include the squat and leg press. The isolation movement (i.e. targets solely the quadriceps) is the leg extension exercise. Sprinting, as well as intense anaerobic running, may be an effective muscle building exercise.

Additional images[edit]

References[edit]

  1. ^ Therapeutic Exercises, Carolyn Kisner & Lynn A. Colby, 5th ed. (2002) 692-93.

External links[edit]