Left vastus medialis: Attachments, Function & 3D

Educational draft · anatomical review pendingSources checked 19 October 2026. Prepared with AI assistance; not yet reviewed by a qualified anatomist. Not for diagnosis or treatment.

Group: Quadriceps femoris
Model side: Left
Main action: Knee extension
Motor nerve: Femoral nerve

Where is vastus medialis?

On the inner side of the thigh, medial to rectus femoris.

This is one of four quadriceps muscles. Use the selected surface as a starting point, then compare the neighboring meshes rather than judging position from the isolated silhouette alone.

Sources: OpenStax

Principal attachments

Its femoral attachments include the medial lip of the linea aspera; the medial intermuscular septum also contributes.

Distally, the quadriceps tendon reaches the patella; the patellar ligament continues to the tibial tuberosity. The model does not separate this complete extensor apparatus into selectable tissues.

Sources: UAMS anatomy table · OpenStax

Function

It extends the knee.

Camera rotation is not joint movement. This viewer cannot demonstrate contraction, strength, tendon loading or an individual's range of motion.

Sources: UAMS anatomy table

Innervation

Motor innervation comes from the femoral nerve. Nerve branches and blood vessels are not loaded, so their paths cannot be inspected in this study.

Sources: UAMS anatomy table

Read the model

Explore left vastus medialis in 3D

Orient the isolated mesh. Rotate toward the inner thigh and inspect the lower end near the patella. Medial means toward the body's midline, not one fixed side of the screen.
Restore this side. Show context loads the existing same-side assembly: 31 bones and 21 muscle parts. It does not switch to the opposite leg or provide a complete dissection.
Compare the four muscles. Open the regional thigh guide for a closer view and side-matched reading links. Left thigh →

What this model can—and cannot—show

BodyParts3D provides this left-sided surface model, not every anatomical variant. Colors distinguish structures; they are not tissue textures.

Oblique and longitudinal fiber regions are not separate selectable structures. Surface color does not show fiber direction.

Joint cartilage, separate ligaments, nerves and vessels are absent. Colored tendon portions are not independent tissue models. Bone landmarks mentioned in the text are not separately clickable.

The left and right study pages share the general anatomical explanation, but open different source-identified meshes. They do not document every individual variation.

A section tool is not available for this structure. The surface model does not reveal internal tissue architecture or represent a medical scan.

Sources and editorial status

This guide uses independently written explanations with links to the evidence behind them. Source checking and specialist anatomical review are separate steps; the latter is still pending.

OpenStax Anatomy and Physiology 2e — Appendicular muscles of the pelvic girdle and lower limbs
Quadriceps positions, group action and the tendon–patella–patellar ligament pathway. No textbook images are reproduced.
University of Arkansas for Medical Sciences — Muscles of the lower limb
Individual quadriceps rows: principal proximal attachments, actions and femoral nerve supply. Attachment descriptions here are introductory, not exhaustive.

3D geometry and its separate license are credited beneath the viewer. References do not imply endorsement of this site.

Left vastus medialis