Muscle of the Month - The Quadriceps

By Susie Black - get free updates of new articles here

One of the biggest muscle groups in your body! What are they? As you can imagine from the name, it's a group of 4 muscles (hence 'quad'). They're the large muscles at the front of the thigh and you can feel them easily whenever you straighten your leg.

Where are they? Three of the four quadricep muscles run from the long bone of the upper leg (femur) to just below the knee joint. The other one is very unusual in that it also crosses the hip joint with a part of this muscle originating from the hip bones.

They're made up of the following:

Rectus Femoris: closest to the skin and running down the front of the thigh, this muscle connects across two joints, the hip and the knee.
Vastus Medialis: running from the outside of the thigh bone across to the inside of the knee joint, you can feel this one just above the knee towards the inner thigh when you straighten your leg.
Vastus Lateralis: you can feel this if you tense the outside of the front of your thigh bone.
Vastus Intermedius: found closer to the bone than the others, you won't be able to feel this one.

What do they do?

These muscles are primarily responsible for straightening our legs. I know that doesn't seem like a hard task but think of how many times a day we expect them to do this. Every step we take, getting up from a chair, any kind of sports, even getting your trews on in the morning! In addition, the rectus femoris muscle which crosses the hip joint is also partly responsible for raising the knee by shortening the angle at the hip joint.

As well as straightening the leg, the other three quadricep muscles pull in slightly different directions to protect the knee joint during movement. The muscles at the back of our thighs can cause a degree of rotation at this joint so these 'front of thigh' muscles work together to ensure this is kept within a safe range.

How do I activate them? These, along with our gluteals, are the most powerful muscles involved in standing up. Sit in a chair and extend your leg out in front of you. You can feel the muscles firming up across the front of your thigh as you lengthen it. With the exception of the Vastus Intermedius, they're quite near the surface and this makes them easy to feel, especially when you tense them.

How do we look after them? Overstrain of these muscles can affect the way the kneecap is supported during movement so it makes sense to look after them. In addition, because they play such a big role in our ability to stand and walk it's imperative that we keep them strong. Think of getting up from a cinema or theatre chair or out of a car after a long time sitting. We need these muscles to immediately get working, not just to get us upright (or stop us from grunting as we raise) but also to protect the angle of the knee joint. If we're forced into a sedentary lifestyle as a result of age-related conditions such as arthritis or joint replacement, these will be the last muscles we should continue to exercise and the first set we get back to moving as soon as we're ready. Luckily enough, walking and biking are two of the best ways to build strength through these muscles and continue to protect the hips, thighs and knees.