Vastus Intermedius Muscle Anatomy

Overview
Origin Anterior and lateral surface of the femur
Insertion Quadriceps tendon, which inserts into the patellar ligament, which inserts onto the tibial tuberosity
Action Extends the knee
Nerve Femoral nerve (L2, L3, L4)
Artery Femoral artery

Location & Overview

The vastus intermedius muscle is one of the four quadricep muscles, The other three are: the vastus lateralis, vastus medialis and rectus femoris. The vastus intermedius is located deep to the rectus femoris, between the vastus medialis and vastus lateralis. It is almost hidden by the other muscles and cannot be palpated [1]. Some studies have also reported a fusion of the vastus intermedius and vastus lateralis muscles [2] [3]. In extreme cases of this fusion, the researchers were unable to distinguish a separation between the vastus intermedius and vastus lateralis muscles and they appeared as one functional muscle [4].

vastus intermedius in isolation

Here we can see the vastus intermedius in isolation. It is deep to the rectus femoris and between the vastus medialis and vastus lateralis.

Origin & Insertion

The vastus intermedius originates on the anterior and lateral surface of the shaft of the femur [5]. The vastus intermedius then inserts into the quadriceps tendon. This quadriceps tendon inserts into the patellar and the patellar tendon inserts onto the tibial tuberosity [6] [7]. Most of the vastus lateralis’ tendon fibres insert at the base of the patella [8].

origin of the vastus intermedius

Here we can see the origin of the vastus intermedius on the anterior and lateral surface of the femur.

insertion of the patellar tendon and vastus intermedius

Here we can see the insertion of the patellar tendon. The vastus intermedius fibres connect into the patellar tendon.

Actions

The vastus intermedius works together with the other quadricep muscles to extend the knee joint [9].

Innervation

The vastus intermedius is innervated by the femoral nerve (L2, L3, L4) [10].

Blood Supply

Blood is supplied to the vastus intermedius via the femoral artery [11].

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Vastus Intermedius Flashcards

References

References
1 Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.
2 Willan PL, Mahon M, Golland JA. Morphological variations of the human vastus lateralis muscle. J Anat. 1990 Feb;168:235-9. PMID: 2323995; PMCID: PMC1256904.
3 Becker I, Woodley SJ, Baxter GD. Gross morphology of the vastus lateralis muscle: An anatomical review. Clin Anat. 2009 May;22(4):436-50. doi: 10.1002/ca.20792. PMID: 19306318.
4 Frohse F, Fränkel M. 1913. Die Muskeln des Menschlichen Beine. In: K Bardeleben, editor. Handbuch der Anatomie des Mensche. 1st Ed. Jena: Gustav Fischer. p 507– 519.
5 Yoshida S, Ichimura K, Sakai T. Structural diversity of the vastus intermedius origin revealed by analysis of isolated muscle specimens. Clin Anat. 2017 Jan;30(1):98-105. doi: 10.1002/ca.22791. Epub 2016 Oct 31. PMID: 27598432.
6 Grob K, Manestar M, Filgueira L, Kuster MS, Gilbey H, Ackland T. The interaction between the vastus medialis and vastus intermedius and its influence on the extensor apparatus of the knee joint. Knee Surg Sports Traumatol Arthrosc. 2018 Mar;26(3):727-738. doi: 10.1007/s00167-016-4396-3. Epub 2017 Jan 25. PMID: 28124107.
7 Yoshida S, Ichimura K, Sakai T. Structural diversity of the vastus intermedius origin revealed by analysis of isolated muscle specimens. Clin Anat. 2017 Jan;30(1):98-105. doi: 10.1002/ca.22791. Epub 2016 Oct 31. PMID: 27598432.
8, 9, 10, 11 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.