Piriformis Trigger Points

What are Trigger Points?

David Keil Anatomy, Yoga Injuries 4 Comments

gluteus minimus trigger points yoga anatomy

The X is where the trigger point is located and the red area is the most common area that the trigger point refers a sensation to.

After my last Muscle of The Month article someone very appropriately asked, “What is a trigger point?” Good question. I shouldn’t have assumed that everyone knew what a trigger point was. I learned about them back in 1997 when I was going through massage school. As it turns out, they are just as relevant now as they were then, when working with students in pain.

Surprisingly there have been studies (referenced in The Trigger Point Manual by Janet Travell and David Simon) that show a large number of people in pain have trigger points as part of their pain pattern. They evaluated everyone who walked into a number of pain clinics around the country. Upon evaluation they found that approximately 80% of the people had trigger points as a component of their pain pattern.

What are Trigger Points?

A trigger point is a spot or a point in a muscle that refers a sensation to another area of the body. The sensation could be:

  • Pain
  • Cold
  • Heat
  • Achiness
  • Weakness
  • Tingling

We can classify trigger points into two categories, latent and active.

A latent trigger point is one that is not actively creating a pain pattern. The pain is either intermittent or not present until the trigger point itself is directly pressed or activated by some activity.

An active trigger point is one that is actively creating pain or another sensation in your body. In other words, if a trigger point was referring pain to your arm, you would be walking around with pain in your arm on a regular basis.

What Causes Trigger Points to Form?

  • Blunt trauma – such as a car accident or a fall.
  • Overuse – perhaps a muscle working too hard by compensating for other muscles.
  • Lack of use – muscle dysfunction and a decrease in lack of blood flow can be due to lack of use. This can lead to the formation of trigger points.

Not to get too technical but… we are talking about dysfunction on the cellular level. A small number of muscle cells remain in a state of contraction when a trigger point exists. Why? This usually occurs because the calcium used to change the charge inside the cell, which causes the contraction to happen, is not removed or neutralized. As a result the cells stay in a state of contraction.

This forms a small bolus or a tiny “knot” in the muscle at a cellular level. It’s not that the entire muscle is in a state of contraction, just “X” number of muscles cells.

How Do You Get Rid Of A Trigger Point?

The way in which Dr. Janet Travell used to get rid of them is a technique called “spray and stretch.” This technique is described in her book The Trigger Point Manual. This is not a realistic technique for yoga teachers to employ, however it is interesting.

Dr. Travell would spray a vapo-coolant over the skin, along the line of the trigger point referral area, while simultaneously stretching the muscles. If this method was not effective enough she would also employ trigger point injections. In this scenario a needle and syringe full of an analgesic would be used and the trigger point itself would be injected.

There are other options.

Following closely with the injection is dry needling which has also been shown to be effective.

The method I employ most commonly goes back to my days in massage school. In a yoga room this method boils down to focusing pressure on the trigger point itself, not necessarily on the area where the trigger point is referring to. Better still is a very specific treatment of the muscle by a qualified therapist.

These methods do a few things.

Both force fluid away from the trigger point. When released, fresh fluid comes back in. In simple terms we are flushing out the area where waste and toxins may have built up and led to enough dysfunction to cause the trigger point or maintain an environment that keeps it going.

The direct pressure on the trigger point can help to “reset” the neuromuscular junction and the exact area where the physiological dysfunction is happening. It essentially plays with the nervous system.

The other method that we are all employing on the yoga mat is to stretch the very muscle that has the trigger point in it. Stretching the muscle, even without a vapo-coolant, can help alleviate the trigger points.

Be mindful though that contracting the muscle, or stressing and straining the muscle may exacerbate the problem.

What Are the Symptoms of a Trigger Point?

Please be careful as you read this next section. Differentiating between a trigger point and an injury is a tricky business. Unless you are a doctor, you have no right to diagnose anyone with any type of condition. All I will do here is share the most typical symptoms exhibited by trigger points. You have to hold onto the idea that these descriptions of pain could be associated with a number of other conditions.

The most common description that I’ve heard of trigger point pain is that there is a dull achiness or that the area feels weak or dead.

Sometimes the pain is described as coming and going away. I then question the person to see if this is especially true related to changes in body temperature.

In other words, say a student has pain somewhere. As they start to practice, the pain goes away. After they “cool off” the pain returns. This is a good indication that it’s a muscular problem. Of course, go confirm this with a medical professional!

Some other clues I’ve learned to use relate to the population of people that I used to treat in my chronic pain clinic. Very often I would have people showing up after having been through some type of medical odyssey. What I mean by this is that they had had every test possible, x-ray, MRI, and all the other goodies and the results were… Negative. No one could find anything. For me, this is a very good indication that trigger points are involved, because they just won’t show up on tests like that.

So when a student complains about a pain pattern that has been around for a while, I will usually ask if they’ve been to a doctor or if they have had any images taken. That type of information is very helpful for knowing what it may or may not be. It helps rule things in or out.



This article was not an attempt to make you into any type of therapist or diagnostician. It was however an attempt to explain (in as simple terms as possible) what a trigger point is. It’s important for us as yoga teachers to be aware that pain shows up in different ways from different sources.

By knowing if I’m dealing with a trigger point or not, I make different choices about what I have students do, how they do it, and how I may or may not adjust them in certain postures. Information is good. From there, you can make more informed decisions.

The most important takeaway is that pain may be coming from a relatively distant source, not necessarily where the pain itself is felt.

Here is a link to a great Self Treatment Book: The Trigger Point Therapy Workbook: Your Self-Treatment Guide for Pain Relief

Keep Exploring,


Additional Resources


The Trigger Point Therapy Workbook: Your Self-Treatment Guide for Pain Relief

rotator cuff trigger points

Rotator Cuff Trigger Points are very common among yoga practitioners.

Many of the concepts in this article are discussed in:
Functional Anatomy of Yoga


Yoga Anatomy research
Yoga Anatomy Book Buy Now

About David Keil

david keil yoga anatomyThis website is simply about delivering yoga anatomy to the yoga community in a simple and understandable way. It has always been about you, the reader, understanding the complexity and diversity of our own humanness as well as our anatomy.

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Comments 4

  1. Hi David. I am also a massage therapist and yoga teacher, and I always learn so much from you. This article was yet another wonderful informative post with your material presented in a straight forward, easy to understand way. You will be at “my teacher’s” school, Asheville Yoga Center, this year, and I have a conflict that weekend. I am very bummed. I do look forward to studying under you someday though. I am currently in training to be a yoga therapist with Holistic Yoga Therapy Institute http://www.yogaclub.us/teachertraining_immersions.htm, and I would be pumped if you could do any of our trainings!!!
    Namaste and keep up the good work of educating us in your fun style.
    Johnna Langlo

  2. Thanks for this great article. This helps alot. I have a yoga client with recurring SI joint pain. Yoga has been relieving it for him. Would you recommend I tell him to try using a vapo-coolent on the area before practice? I have told him to make sure he has plenty of rest between yoga session, leaving at least a day off in between for now as to not irritate the area by practicing too much.


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