Featured Muscle: Popliteus

As I was running downhill during boot camp this morning, I was focused on letting my body loosen and allowing gravity to take over. In that moment, my thoughts quickly spiraled … causing me to question how the heck my knee was being stabilized under the force of gravitational pull and momentum. Then I remembered this very special, quiet, and somewhat unknown muscle: the popliteus. I quietly thanked the popliteus for stabilizing my knee and making it possible for me to run downhill with some sense of control. Cheers to the popliteus! Let’s learn more about this important muscle:

I give this muscle the award of “Biggest Little.”

Many people – including healthcare professionals – underestimate the value of this small but significant muscle. I bet you’re even saying now, “I’ve never heard of that muscle. Is Corey making this up? How can it possibly be so important?” Read on, and prepare to be converted.

popliteus muscle

What is the Popliteus?
The Popliteus is located on the posterior aspect (back side) of the knee, attaching from the lateral (outside) of the femur to the medial (inside) of the tibia. It is best known for its job as a stabilizing muscle of the posterior knee.

What does the Popliteus do?
The popliteus is believed to have a number of functions, made possible by its unique ability to reverse its origin and insertion, depending on whether the femur or the tibia is fixed.

One of its primary tasks is to unlock the knee just after the heel touches the ground when you are walking or running. This action allows you to slightly bend the knee and absorb the impact the moment your heel hits the ground. If this mechanism was not in place each time we took a step our knee would lock and get stuck. There would be no force rotating the bones ensuring successful movement. Without the popliteus walking and running would be extremely difficult and painful.

It also has an important role when running downhill. It works with the posterior cruciate ligament, PCL in decelerating the femur thus preventing its sliding forward on the tibia from the gravity force. Imagine you are walking or running downhill, momentum and gravity are at play. If you didn’t have the popliteus you would lose the ability to slow and/or stop your movement. The femur would literally slide forward over the knee joint.

Lastly, the popliteus pulls on the lateral meniscus while bending the knee. This action creates space for the lateral meniscus, thus providing the ability for the meniscus to act as the shock absorber without restriction from entrapment. Otherwise, the meniscus would get smashed between the tibia and the femur and not be able to do its job properly.

Popliteus Syndrome
The popliteus’s small (yet immensely important) role in gait function and its deep location cause it to go unsuspected and underestimated by a lot of healthcare professionals. If you find yourself with a mysterious knee pain, consider the following:

Symptoms of Popliteus Syndrome

  • Feels like tendonitis. Tendonitis is a progressive pain that often feels like a dull ache. With time, that pain progresses into a sharp, more constant pain.
  • Pain pattern is typically felt at the medial attachment on the tendon. This is located on the inside of your knee.
  • Sudden or unexplained “locking” feeling of the knee.

Causes of Popliteus Syndrome

  • Because of its role assisting the PCL, people will start developing symptoms after long hill-training sessions, or after a long downhill hike.
  • People with a history of knee injury are more likely to develop popliteus syndrome. Often, because it is over worked trying to stabilize the knee.
  • Low back dysfunction. Even if no lower back pain is present, dysfunction can exist that causes a nerve stimulation that refers to the popliteus resulting in trigger points and pain in the back of the knee.

Popliteus Syndrome Treatment
Popliteus syndrome is fairly easy to treat and has a high recovery rate.

If your pain is caused by recent exercise, follow these tips:

  • Rest
  • Anti-inflammatory treatment (ice, physician recommended medications)
  • Professional and targeted massage treatment; Gentle massage during first stages of healing is recommended
  • Gentle stretching
  • As pain subsides, you should begin strengthening and have deeper massage to break down scar tissue

If your pain is a result of an unstable knee from past injury, follow these tips:

  • Professional and targeted massage to treat tension and scar tissue
  • Seek recommendations for strengthening and stabilizing the knee joint from a trusted physical therapist or personal trainer
  • Rest
  • Anti-inflammatory treatment (ice, physician recommended medications)

4 comments on “Featured Muscle: Popliteus

    • Hi Jeff. I agree, I think it’s really cool to look at these lesser known yet extremely important muscles.

    • Hi Seepow. I love this question. One of the primary functions of the popliteus is to unlock the knee. Keeping the in mind, the popliteus is primarily at work during the plank to standing position transition and also when transitioning from standing position to your squat.

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