The outer quadriceps
Vastus lateralis · musculus vastus lateralis
The biggest of the quadriceps, on the outer side of your thigh.
What it does
The vastus lateralis covers the outer front of the thigh, running from the top of the femur to the kneecap. With the other quadriceps it straightens the knee, which you need for standing up, climbing stairs and landing from a jump.
Surprising fact
It is the largest of the four quadriceps, and scientists often take tiny muscle samples from it because it is big, accessible and easy to study.
Why it matters
It is a recommended spot for injections in babies and young children, because their thigh muscle is better developed than their shoulder.
Nearby
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.