- Vastus medialis
Infobox Muscle
Name=PAGENAME
Latin=
GraySubject=128
GrayPage=471
Caption=Vastus medialis
Caption2=Muscles of lower extremity
Origin=femur
Insertion=patella
Blood=femoral artery
Nerve=femoral nerve
Action=extends leg
DorlandsPre=
DorlandsSuf=|The vastus medialis, often called the 'teardrop' muscle, is a
medially locatedmuscle of thequadriceps .Function
Vastus medialis has been widely reported to be responsible for extending the leg the last 10%, however this commonly held claim has no basis, indeed there is a reasonable body of evidence to the contrary. Fact|date=March 2008 The vasti instead appear to act largely in a co-ordinated manner throughout the control of knee extension.
Much has been made of the ability of the Vastus Medialis to translate the patella medially, however since approximately 70% of the contractile fibres attach directly to the common extensor tendon (which then inserts centrally to the superior patella) the functional ability to achieve this goal may be overstated, and is likely dwarfed by the bony congruence of the patella in the trochlea notch. Some authorities maintain there is a separate aspect to the Vastus Medialis muscle - the "Vastus Medialis Obliquus"cite journal |author=Toumi H, Poumarat G, Benjamin M, Best T, F'Guyer S, Fairclough J |title=New insights into the function of the vastus medialis with clinical implications |journal=
Med Sci Sports Exerc |volume=39 |issue=7 |pages=1153–9 |year=2007 |pmid=17596784 |doi=10.1249/01.mss.0b013e31804ec08d |url=http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?an=00005768-200707000-00017] or more commonly the "VMO"cite journal |author=Peeler J, Cooper J, Porter MM, Thliveris JA, Anderson JE |title=Structural parameters of the vastus medialis muscle |journal=Clin Anat |volume=18 |issue=4 |pages=281–9 |year=2005 |pmid=15832351 |doi=10.1002/ca.20110] which is reported to have a more oblique or horizontal orientation to the bulk of the remainder of the muscle thereby disposing it to be better able to 'pull' the patella medially. Unfortunately careful inspection of many cadavers reveals that the fibres of the Vastus Medialis are largely parallel and there is no significant separate aspect of the contractile fibres fitting this description which would suggest it is time to lay this clinical myth to rest. Often medical and other allied health practitioners suggest improving the strength and/or activation of this muscle as a strategy in the treatment of anterior knee pain - sometimes calledrunner's knee .Lunges are an exercise sometimes used to target this muscle.
Origin and insertion
It arises from the lower half of the
intertrochanteric line , the medial lip of thelinea aspera , the upper part of themedial supracondylar line , the tendons of theAdductor longus and theAdductor magnus and the medial intermuscular septum.Its fibers are directed downward and forward, and are chiefly attached to an
aponeurosis which lies on the deep surface of the muscle and is inserted into the medial border of thepatella and theQuadriceps femoris tendon, an expansion being sent to the capsule of theknee-joint .Relations
The Vastus medialis and
Vastus intermedius appear to be inseparably united, but when theRectus femoris has been reflected a narrow interval will be observed extending upward from the medial border of the patella between the two muscles, and the separation may be continued as far as the lower part of the intertrochanteric line, where, however, the two muscles are frequently continuous.
=AdditionalReferences
External links
* [http://www.kneeguru.co.uk/KNEEnotes/node/833 The KNEEguru - educational site packed with knee content with sections on the quadriceps muscle]
*MuscleLoyola|vasm
*ViennaCrossSection|pembody/body18b
*eMedicineDictionary|Vastus+medialis+muscle
* [http://www.ptcentral.com/muscles/musclelegs.html#vastus%20medialis PTCentral]
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