Vastus Medialis Muscle Anatomy

Overview
Origin Inferior part of the intertrochanteric line
Spiral line
Medial lip of the linea aspera
Proximal part of the medial supracondylar line
Adductor longus muscle
Adductor magnus muscle
Medial intermuscular septum
Insertion Medial border of the patella
Quadricep/patellar tendon
The patellar tendon inserts onto the tibial tuberosity
Action Extends the knee
Nerve Femoral nerve
Artery Femoral artery

Location & Overview

The vastus medialis is the most medial of the four quadriceps muscles. The remaining three are: the rectus femoris, vastus intermedius and the vastus lateralis. The vastus medialis is located in the medial thigh within the anterior compartment of thigh [1].

The most distal muscle fibres of the vastus medialis are usually referred to as the vastus medialis oblique (VMO) [2]. There has been some discussion in the past as to whether the VMO is actually a separate muscle with its own innervation. This is because some anatomy studies had not found it to be separate [3] [4] [5]. However, in general, the presence of the VMO is often accepted by anatomists and surgeons [6]. Research has also shown that the VMO is innervated by a distinct branch of this femoral nerve comparative to the rest of the muscle [7]. It is thought that weakness in the VMO can lead to patellofemoral pain syndrome. The cause of the condition is thought to be due to an imbalance in the activity between the VMO and the vastus lateralis muscle [8].

vastus medialis muscle from a superficial view

Here we can see the vastus medialis muscle from a superficial view amongst the other muscles of the thigh. The vastus medialis is highlighted in green.

vastus medialis in isolation

Here we can see just the vastus medialis in isolation.

Origin & Insertion

The vastus medialis originates from the inferior part of the intertrochanteric line, spiral line (pectineal line), medial lip of the linea aspera, proximal part of the medial supracondylar line, the adductor longus, adductor magnus and medial intermuscular septum (fascia) [9].

The vastus medialis inserts at the medial border of the patella and also into the patellar tendon [10] [11] [12].

vastus medialis anterior origins

Highlighted in red we can see the vastus medialis’ anterior origin points (inferior part of the intertrochanteric line and the spiral line which is also known as the pectineal line).

vastus medialis posterior origins

Highlighted in red we can see the vastus medialis’ posterior origin points (medial lip of the linea aspera and the proximal part of the medial supracondylar line).

Highlighted in blue, we can see the insertion of the patellar tendon. The vastus medialis inserts into the quadriceps tendon which then inserts into the patellar tendon.

vastus medialis insertion on the medial side of the patella

Highlighted in blue here we can see another one of the insertion points of the vastus medialis, on the medial side of the patella.

Actions

The vastus medialis’ primary action is extension of the knee. It works alongside the other quadricep muscles (the rectus femoris, vastus intermedius and the vastus lateralis) to extend the knee. It also works together with the vastus lateralis to stabilise the knee joint [13] [14].

Innervation

The vastus medialis is innervated by the femoral nerve. The distal oblique fibers (the VMO) are innervated by a distinct branch of this femoral nerve comparative to the rest of the muscle [15].

Blood Supply

Blood is supplied to the vastus medialis from the superficial femoral artery as well as the deep femoral artery [16].

Want some flashcards to help you remember this information? Then click the link below:
Vastus Medialis Flashcards

References

References
1 Waligora AC, Johanson NA, Hirsch BE. Clinical anatomy of the quadriceps femoris and extensor apparatus of the knee. Clin Orthop Relat Res. 2009;467(12):3297-3306. doi:10.1007/s11999-009-1052-y
2, 6 Waligora AC, Johanson NA, Hirsch BE. Clinical anatomy of the quadriceps femoris and extensor apparatus of the knee. Clin Orthop Relat Res. 2009;467(12):3297-3306. doi:10.1007/s11999-009-1052-y
3 Hubbard JK, Sampson HW, Elledge JR. Prevalence and morphology of the vastus medialis oblique muscle in human cadavers. Anat Rec. 1997 Sep;249(1):135-42. doi: 10.1002/(SICI)1097-0185(199709)249:1<135::AID-AR16>3.0.CO;2-Q. PMID: 9294658.
4 Lefebvre R, Leroux A, Poumarat G, Galtier B, Guillot M, Vanneuville G, Boucher JP. Vastus medialis: anatomical and functional considerations and implications based upon human and cadaveric studies. J Manipulative Physiol Ther. 2006 Feb;29(2):139-44. doi: 10.1016/j.jmpt.2005.12.006. PMID: 16461173.
5 Peeler J, Cooper J, Porter MM, Thliveris JA, Anderson JE. Structural parameters of the vastus medialis muscle. Clin Anat. 2005 May;18(4):281-9. doi: 10.1002/ca.20110. PMID: 15832351.
7, 10, 15 Toumi H, Poumarat G, Benjamin M, Best TM, F’Guyer S, Fairclough J. New insights into the function of the vastus medialis with clinical implications. Med Sci Sports Exerc. 2007 Jul;39(7):1153-9. doi: 10.1249/01.mss.0b013e31804ec08d. Erratum in: Med Sci Sports Exerc. 2008 May;40(5):982. Best, Thomas [corrected to Best, Thomas M]. PMID: 17596784.
8 Waryasz GR, McDermott AY. Patellofemoral pain syndrome (PFPS): a systematic review of anatomy and potential risk factors. Dyn Med. 2008 Jun 26;7:9. doi: 10.1186/1476-5918-7-9. PMID: 18582383; PMCID: PMC2443365.
9 Rajput HB, Rajani SJ, Vaniya VH. Variation in Morphometry of Vastus Medialis Muscle. J Clin Diagn Res. 2017;11(9):AC01-AC04. doi:10.7860/JCDR/2017/29162.10527
11 Bryce TH. Quain’s Elements of Anatomy. Vol IV, Part II, Myology. London, United Kingdom: Longmans Green and Co; 1923.
12 Sonin AH, Fitzgerald SW, Bresler ME, Kirsch MD, Hoff FL, Friedman H. MR imaging appearance of the extensor mechanism of the knee: functional anatomy and injury patterns. Radiographics. 1995 Mar;15(2):367-82. doi: 10.1148/radiographics.15.2.7761641. PMID: 7761641.
13 Hyong IH, Kang JH. Activities of the Vastus Lateralis and Vastus Medialis Oblique Muscles during Squats on Different Surfaces. J Phys Ther Sci. 2013;25(8):915-917. doi:10.1589/jpts.25.915
14 Bordoni B, Varacallo M. Anatomy, Bony Pelvis and Lower Limb, Thigh Quadriceps Muscle. 2021 Jul 22. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. PMID: 30020706.
16 Jordan JA, Burns B. Anatomy, Abdomen and Pelvis, Hip Arteries. [Updated 2021 Jul 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542174/