Editing Quadriceps (section)

==Structure==
[[File:Quadriceps.png|left|thumb|200px|The quadriceps consists of four separate muscles([[vastus intermedius muscle]] is not shown as it is deep to [[rectus femoris muscle]])]]

===Parts===
The quadriceps femoris muscle is subdivided into four separate muscles (the 'heads'),<ref name=":0" /><ref>{{Citation|last=Chaitow|first=Leon|title=Chapter 13 - The knee|date=2011-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780443068157000139|work=Clinical Application of Neuromuscular Techniques, Volume 2 (Second Edition)|pages=447–501|editor-last=Chaitow|editor-first=Leon|place=Oxford|publisher=Churchill Livingstone|language=en|doi=10.1016/b978-0-443-06815-7.00013-9|isbn=978-0-443-06815-7|access-date=2020-12-23|last2=DeLany|first2=Judith|editor2-last=DeLany|editor2-first=Judith|url-access=subscription}}</ref> with the first superficial to the other three over the [[femur]] (from the [[trochanter]]s to the [[condyle]]s):
* The [[rectus femoris muscle]] occupies the middle of the thigh, covering most of the other three quadriceps muscles.<ref name=":0">{{Citation|last=Bakkum|first=Barclay W.|title=Chapter 4 - Muscles That Influence the Spine|date=2014-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780323079549000049|work=Clinical Anatomy of the Spine, Spinal Cord, and Ans (Third Edition)|pages=98–134|editor-last=Cramer|editor-first=Gregory D.|place=Saint Louis|publisher=Mosby|language=en|doi=10.1016/b978-0-323-07954-9.00004-9|isbn=978-0-323-07954-9|access-date=2020-12-23|last2=Cramer|first2=Gregory D.|editor2-last=Darby|editor2-first=Susan A.|url-access=subscription}}</ref> It originates on the [[ilium (bone)|ilium]]. It is named for its straight course.
* The [[vastus lateralis muscle]] is on the ''lateral side'' of the femur (i.e. on the outer side of the thigh).<ref name=":0" />
* The [[Vastus medialis|vastus medialis muscle]] is on the ''medial side'' of the femur (i.e. on the inner part thigh).<ref name=":0" />
* The [[vastus intermedius muscle]] lies between vastus lateralis and vastus medialis on the ''front'' of the femur (i.e. on the top or front of the thigh), but deep to the rectus femoris muscle. Typically, it cannot be seen without dissection of the rectus femoris.<ref name=":0" />

===Attachments===
The rectus femoris arises from the [[anterior inferior iliac spine]] and from the superior edge of the [[acetabulum]].<ref name=":0" /> It is thus a [[biarticular muscle]]. The other parts of the quadriceps arise from the surface of the femur. All four parts of the quadriceps muscle ultimately insert into the [[tuberosity of the tibia]] via the [[patella]], where the [[quadriceps tendon]] becomes the [[patellar tendon]].<ref name=":0" />

===Other muscles===
There is a small fifth muscle of the quadriceps complex—the [[articularis genus muscle]]—that is not often included.

In addition, [[cadaver]] studies have confirmed the presence of a sixth muscle, the [[Tensor vastus intermedius muscle|tensor vastus intermedius]].<ref name="Grob_2016">{{cite journal|last1=Grob|first1=K|last2=Ackland|first2=T|last3=Kuster|first3=MS|last4=Manestar|first4=M|last5=Filgueira|first5=L|title=A newly discovered muscle: The tensor of the vastus intermedius|journal=Clinical Anatomy|date=6 January 2016|volume=29|issue=2|pages=256–263|doi=10.1002/ca.22680|pmid=26732825|s2cid=38157592|url=http://doc.rero.ch/record/258954/files/fil_ndm.pdf}}</ref> While this muscle has a variable presentation, it consistently originates at the proximal femur, runs between the vastus lateralis and vastus intermedius muscles, and inserts distally at the medial aspect of the patellar base.<ref name="Grob_2016" /> Historically considered a part of the vastus lateralis muscle, the tensor vastus intermedius muscle is innervated by an independent branch of the [[femoral nerve]] and its tendinous belly can be separated from the vasti lateralis and intermedius muscles in most cases.<ref name="Grob_2016" />

===Innervation===
The quadriceps femoris is innervated by the femoral nerve, which originates from L2, L3, L4.<ref name=":0" /><ref name=":1">{{Citation|last=Felten|first=David L.|title=9 - Peripheral Nervous System|date=2016-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780323265119000096|work=Netter's Atlas of Neuroscience (Third Edition)|pages=153–231|editor-last=Felten|editor-first=David L.|place=Philadelphia|publisher=Elsevier|language=en|doi=10.1016/b978-0-323-26511-9.00009-6|isbn=978-0-323-26511-9|access-date=2020-12-23|last2=O'Banion|first2=M. Kerry|last3=Maida|first3=Mary Summo|editor2-last=O'Banion|editor2-first=M. Kerry|editor3-last=Maida|editor3-first=Mary Summo|url-access=subscription}}</ref>