Jan 2015 24

The quadriceps

By: Dave Wheeler

In a previous blog post about the patellar tendon, I've mentioned the muscles at the front of the thigh - the quadriceps.

In this post, we'll look in closer details at each of the 4 quads.


Pic by wikicommons.org


The quadriceps femoris group

There are 4 quads in what is know officially the quadriceps femoris group of muscles:

  1. Rectus femoris ("Rec Fem", in blue above)
  2. Vastus medialis (in red)
  3. Vastus lateralis (in yellow)
  4. Vasus intermedialis (in green)


Together they work to perform the kicking action from the knee. This action is known as knee extension.

As the diagram above shows, all of the muscles of the quads begin high up on the thigh towards the hip, and run down the leg over the knee joint and attach on the lower leg bone (called the tibia) just below the knee.

This means that when the muscles of the quads contract, they lever the lower leg up at the knee.

As the previous blog post mentioned, all 4 quadriceps converge towards the bottom of the thigh, just above the knee, to form the patellar tendon. It's this tendon that passes under the kneecap and attaches to the front-side top of the tibia (this is called the insertion of the muscles).

So the power of these 4 big muscles all pull on this one tendon. This is why the kicking action can be so strong.

Any movement that involves bending the knee is going to use the quadriceps group, for example:


  • skiing or snowboarding
  • squats
  • football

If you have the kyphotic-lordotic posture type, then just because of the way that you hold your body if you run or do a lot or walking then you'll be using your quads a lot too.

In any of these cases, you may find that overuse of the quads will mean that they'll be tight.


Vastus Medialis, lateralis and intermedialis

The common feature of the 3 quad muscles with vastus in the name is that they all start (that is, their origin is at) the very top of the thigh bone, the femur.

This means that these 3 vastus muscles only cross one joint - the knee. Since the job of muscles is to pull on bones (in this case the tibia of the lower leg), the vastus muscles of quads only have one action - to bend (extend) the knee.

The location of each of the muscles is pretty obvious from their names:

  • Vasus medialis is a teardrop shaped muscle that lies on the insdie front of the thigh (medialis is latin for middle; in other words, towards the mid-line of the body)
  • Vastus lateralis sits on the outside of the leg (lateralis is latin for lateral, in other words, on the outside of the body)
  • Vastus intermedialis (that one speaks for itself - intermediate, between the other two vastus muscles)

Both vastus medialis and vastus intermedialis are superficial muscles which means that they lie close the surface and are easy to massage. Vastus intermedialis is deeper to the other quadriceps - it can really only be felt directly close to the knee.

For some people, especially those whose posture, lifestyle or exercise means that they're overusing their quads, one part of vastus medialis can become overdeveloped.

Vastus medialis obliquus (VMO) is the lowest segment of that particular muscle, closest to the knee. It can sometimes become overdeveloped. When this happens, the tracking of the knee can be affected - your knee can be pulled inwards.



You can check your knee tracking really easily. Stand with your feet exactly parallel, facing forward, shoulder width apart. Now squat by bending your knees. If your knees are tracking correctly, then they will come forward over your toes. If one or other (or both) your knees come in towards the centre line, then your VMO is hypertonic - it's being overused.

Soft tissue release (STR) is a great treatment for hypertonic VMO muscle fibres, but needs to be combined with massage to warm you up first, otherwise it can be quite painful.


Rectus Femoris

Rec fem, the rectus femoris muscle within the quadricep group is slightly different to the other 3.

Whilst it, too, crosses the knee and therefore helps create knee extension, at the top  it attaches to a different place to the vastus group.

The origin of rec fem is the front of the pelvis, so it attaches to the hip rather than the thigh bone. It's the only one of the quadriceps to cross two joints.

Because rec fem attaches to the hip, it means that when the upper fibres contract, it will bend the hip forward, a movement known as hip flexion.

Rec fem can often become overly tight, and when it does muscle energy technique can be a really effective treatment. The traditional deep tissue approach of regular sports massage isn't great on rec fem as is lies directly on top of the femur (the thigh bone), and too much pressure will hurt and possibly even bruise the muscle.


The quads as you get older

When you're in the first half of your life and you're active, it's possible that you'll get the odd ache in the quads from overuse or unusual use. In certain cases, injury can occur at the insertion where the tendon passes underneath the patellar.

Acute injury of the insertion is rare in the vastus muscles, and not at all common in rec fem. But chronic overuse at the hip can cause problems in rec fem, a problem that's more likely to show as you age.

If you've got aches and pains in your quads, in the tendon of your knee, or at the front of your hip and you think I can help, give me a call - whatever stage of life your at.