Vastus medialis muscle

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Vastus medialis muscle
Vastus medialis muscle.png
anterior thigh muscles
origin
Inner surface of the femur , distal part of the intertrochanteric line
approach
External surface of the kneecap , tibial tuberosity of the tibia
function
Extensor of the knee joint
Innervation
Femoral nerve
Spinal segments
L2-L4

The vastus medialis muscle ( Latin , literally: "to the middle [lat. Medius central, in the middle, in between] located broad [lat. Vastus huge, wide] muscle", German: "inner thigh muscle "; old name: Musculus vastus tibialis ) is one of the anterior muscles of the thigh . It is a head of the quadriceps femoris muscle ("four-headed thigh muscle"). This quadriceps , as its name suggests (Latin quadr- four- and -ceps -headed), has four heads. The vastus muscle has three of these four heads. This is to the vastus intermedius , the vastus lateralis and around the vastus medialis . These three individual muscles are joint muscles in that they only act on the knee joint.

The kneecap is embedded in the tendon of the quadriceps as a sesamoid . The tendon is finally attached to the tibial tuberosity of the shinbone via the patellar ligament and thus forms the insertion of the muscle . The belly of the vastus medialis muscle extends further towards the knee than that of the vastus lateralis muscle , creating the so-called suprapatellar bulge , a protrusion above the kneecap.

The vastus medialis muscle can functionally be divided into two parts, which are anatomically neither separated by tendon irradiation nor have a separate innervation. The main part, the vastus medialis longus muscle (lat. Longus 'long'), has its origin with a roughly vertical fiber course on the inner surface of the thigh bone ( Linea aspera on the femur up to the crista intertrochanterica on the greater trochanter ) and its attachment to the kneecap. The knee Windwärts preferred portion of the muscle, the vastus medialis obliquus (lat. Obliquus obliquely '; light red in the adjacent figure), on the other hand arises from the tendon of the musculus adductor magnus and pulls with oblique to almost horizontal fiber flow to the inner side of the patella. Both muscle parts also differ in the muscle fiber composition: In the inclined part, fast-twitch type 2 fibers dominate . However, the two portions (as well as the generic term Musculus vastus ) are not shown in the current Terminologia Anatomica .

function

The vastus medialis muscle , together with the three other parts of the quadriceps femoris muscle, extends the knee joint (extension of the lower leg). In addition, the tension of the muscle fiber strands of the muscle (vastus medialis obliquus) running horizontally in the direction of the kneecap has a stabilizing effect on the kneecap. This pull (horizontal force component) counteracts the laterally directed sideways pull of the remaining quadriceps parts and centers the kneecap in the joint surface of the thigh bone. Damage to the muscle leads to a sideways tilt and a displacement of the kneecap with an increase in the contact pressure on its outside, with a reduction in joint contact on its inside and with a resulting reduced stability of the knee joint.

The vastus medialis muscle is innervated by the femoral nerve ( Nervus femoralis ), which sends its own ramus muscularis (muscle branch) into the muscle, which branches out there.

literature

Individual evidence

  1. ↑ Duden : The dictionary of medical terms . 4th edition. Bibliographisches Institut, Mannheim / Vienna / Zurich 1985, ISBN 3-411-02426-7 , ISBN 3-13-437804-3 , p. 462.
  2. ↑ Willibald Pschyrembel: Clinical Dictionary . 61st to 84th edition. Walter de Gruyter Verlag, Berlin 1944, p. 487.
  3. ↑ Maxim Zetkin , Herbert Schaldach: Dictionary of Medicine . 15th edition. Verlag Ullstein Mosby, Berlin 1992, ISBN 3-86126-015-8 , ISBN 3-86126-018-2 , p. 1413.
  4. ^ Hexal Lexicon Orthopedics, Rheumatology . Urban & Schwarzenberg, Munich / Vienna / Baltimore 1992, ISBN 3-541-16421-2 , p. 200.
  5. ↑ Johannes Sobotta , Hellmut Becher : Atlas of Human Anatomy , Volume I. 17th edition. Urban & Schwarzenberg, Munich / Berlin / Vienna 1972, ISBN 3-541-02817-3 , reprint 1979, p. 233.
  6. ^ Günter Thiele (ed.): Handlexikon der Medizin . Urban & Schwarzenberg, Munich / Vienna / Baltimore without year, Volume 3 (L – R), p. 1647.
  7. ^ HB Rajput, SJ Rajani, VH Vaniya: Variation in Morphometry of Vastus Medialis Muscle. In: Journal of clinical and diagnostic research: JCDR. Volume 11, number 9, September 2017, pp. AC01 – AC04, doi: 10.7860 / JCDR / 2017 / 29162.10527 , PMID 29207687 , PMC 5713709 (free full text).
  8. ↑ L. Travnik, F. Pernus, I. Erzen: Histochemical and morphometric characteristics of the normal human vastus medialis longus and vastus medialis obliquus muscles. In: Journal of anatomy. Volume 187 (Pt 2), October 1995, pp. 403-411, PMID 7592003 , PMC 1167435 (free full text).
  9. ^ Terminologia Anatomica
  10. ↑ Willibald Pschyrembel: Clinical Dictionary . 264th edition. Walter de Gruyter Verlag, Berlin / Boston 2012, ISBN 978-3-11-027788-3 , p. 1384. What is probably meant is the extension of the leg in the knee joint.
  11. ↑ Michael Schünke: Functional Anatomy - Topography and Function of the Movement System . Georg Thieme, Stuttgart 2000, ISBN 978-3-13-118571-6 , p. 344.
  12. ^ J. Stephen, A. Alva, P. Lumpaopong, A. Williams, AA Amis: A cadaveric model to evaluate the effect of unloading the medial quadriceps on patellar tracking and patellofemoral joint pressure and stability. In: Journal of experimental orthopedics. Volume 5, number 1, September 2018, p. 34, doi: 10.1186 / s40634-018-0150-8 , PMID 30203221 .
  13. ^ Roche Lexicon Medicine . 5th edition. Urban & Fischer, Munich / Jena 2003, ISBN 3-437-15156-8 , p. 1262.
  14. ↑ Frank Henry Netter : Color Atlases of Medicine . Volume 5. Georg Thieme Verlag, Stuttgart / New York 1987, ISBN 3-13-524401-6 , p. 123.