What Are Trigger Points? A Practical Guide to Muscle Knots and Referred Pain

Most people who use massage tools are not interested in debating the definition of a trigger point. They know what they feel. There is one spot in the shoulder, neck or back that is different from everything around it. It feels tighter. Pressing it hurts in a strangely familiar way. 

Sometimes the pain even shows up somewhere other than where you are pressing.

We usually call it a muscle knot. In clinical literature, a related term is myofascial trigger point. The name is useful. But I think the way we talk about trigger points often creates the wrong picture.

A trigger point is not a tiny knot tied inside your muscle, waiting for somebody to press hard enough to break it. That simple distinction changes how I think about massage.

What are you actually feeling?

A trigger point is generally described as a sensitive spot associated with a taut band of skeletal muscle. Some are painful without being touched. Others are almost invisible in daily life until you press directly into them.

What makes them interesting is that the pain is often very specific. You can move a finger half an inch and feel almost nothing, then move back and immediately find the same tender point again.

Researchers have also found measurable differences in some areas identified as trigger points, including differences in tissue stiffness and mechanical properties. So when someone tells me:

“There really is something there.”

I would not dismiss that experience. There may very well be a localized change in the way that area of muscle is behaving. What I would question is the next assumption: “Therefore there must be a physical knot that needs to be crushed.” That part does not follow.

Your muscle has not tied itself into a knot

“Muscle knot” is good everyday language. It describes the sensation well. But muscle is living tissue controlled continuously by the nervous system. It changes its level of contraction according to movement, load, fatigue, pain and sensory information. A tight, tender area is better thought of as a local change in muscle tension and sensitivity.

That may sound less dramatic than a knot. It is also much closer to what the research suggests.

And it immediately explains something important about massage: if there is no literal knot, successful massage does not require us to physically destroy one.

Why does a trigger point become painful?

There is still no single explanation that accounts for every trigger point.One influential model proposes that repetitive loading, prolonged muscle activity or overload can contribute to abnormal activity around the motor endplate — the place where a nerve communicates with a muscle fiber.

Researchers have proposed a cycle in which sustained local muscle activity increases metabolic demand and changes the local biochemical environment. Pain-sensitive nerve endings can then become more responsive.

Human microdialysis studies have found biochemical differences around active trigger points compared with normal muscle, including changes in substances associated with nociception and inflammatory signaling.

That does not prove one neat cause-and-effect story. Human bodies rarely give us stories that neat. But it does help explain why a very small part of a muscle may become disproportionately sensitive.

Why can pressing your shoulder hurt somewhere else?

This is one of the more confusing features of trigger points. You press one place. You feel discomfort somewhere else. This is known as referred pain.

Pain is not a perfect GPS system. Signals coming from muscle, joints and other tissues enter a nervous system that has to interpret where those signals are coming from and how important they are. Sometimes the location where pain is experienced does not perfectly match the tissue contributing to it.

That is one reason people can spend a long time rubbing the place that hurts without finding the area that actually reproduces the familiar discomfort. It is also why I am cautious whenever someone says: “I have pain here, so the problem must be exactly here.” Sometimes it is. Sometimes it is not.

Why does pressure sometimes feel so effective?

This is the part that matters most if you are actually using massage. When pressure is applied to a sensitive muscular area, several things happen at once. The tissue is mechanically loaded.

Sensory receptors are stimulated. The amount and type of information being sent into the nervous system changes. Muscle guarding may change. The same pressure may gradually become easier to tolerate.

Clinical studies of manual trigger-point techniques have reported improvements in pain, pressure-pain threshold and range of motion in some populations. That is meaningful.

But we do not need to invent a little knot-breaking story to explain it. A person may start with an area that feels hard and painful, apply controlled pressure, and notice a minute later that the same area feels softer and less sensitive. That experience is real. Calling it a release is reasonable.

I just would not confuse “release” with “something physically snapped apart.”

Massage can work without “breaking up” anything

This is why I do not think good self-massage should begin with the question: “How hard can I press?”

A better question is: “Can I reach the right place and apply enough pressure to produce a useful response?”

Those are very different goals. More pressure is not automatically better pressure. If muscle knots were physical objects, then force would be simple. Harder should be better. But sensitive muscle does not behave like that. Push too aggressively and the body may tighten against you. The area may become more painful rather than less. You may simply create another source of irritation.

When I think about a self-massage tool, I therefore do not start with: How much force can this tool generate?

I think about: Can the user reach the muscle? Can the pressure be increased gradually?
Can it be held without exhausting the hand? Can the pressure be reduced immediately?

That is what control means. And for self-massage, control matters more than bravado.

Sometimes the real problem is access. Many people have enough strength to massage themselves.

What they do not have is a third hand in the middle of their back. The upper trapezius, back of the shoulder, area around the shoulder blade, lower back and gluteal muscles can all be difficult to reach comfortably. You twist. Your wrist bends. Your fingers fatigue. Your shoulder is working hard while you are supposedly trying to relax it. This is where a manual massage tool makes sense to me. Not because people need to attack themselves with more force. Because leverage can make an awkward area reachable. A good tool should act as an extension of the hand, not a weapon against the muscle.

One tender spot does not explain every pain

I also think massage brands have a responsibility not to call everything a trigger point. A tender spot does not prove the source of pain. Pain may involve muscle, joints, nerves, injury or medical conditions that self-massage cannot diagnose. Trigger-point identification itself is not perfectly reliable, and the science continues to evolve.

If pain is severe, unusual, worsening or accompanied by neurological or other concerning symptoms, repeatedly pressing harder is not a sensible experiment.

Self-massage has limits. That does not make it less useful. It makes it a tool rather than a belief system.

The way I think about trigger point “release”

For me, the most useful definition is simple. A trigger point is a localized area of muscle that has become unusually tense, sensitive or painful. Massage does not need to crush it.

It needs to create the right combination of mechanical pressure, sensory input and time for that area to change. Sometimes the result is subtle. Sometimes it is surprisingly obvious.

The pressure stops hurting as much. The muscle feels less resistant. Movement feels freer.

The spot you could find instantly a minute ago becomes much harder to locate. People call that a release. I am comfortable with the word. I just think we should understand what we mean by it.

References

1. Shah JP, Thaker N, Heimur J, Aredo JV, Sikdar S, Gerber LH. Myofascial Trigger Points Then and Now: A Historical and Scientific Perspective. PM&R. 2015.
2. Gerwin RD, Dommerholt J, Shah JP. An Expansion of Simons' Integrated Hypothesis of Trigger Point Formation. Current Pain and Headache Reports. 2004.
3. Shah JP, et al. Uncovering the Biochemical Milieu of Myofascial Trigger Points Using In Vivo Microdialysis. Journal of Bodywork and Movement Therapies. 2008.
4. Ballyns JJ, et al. Objective Sonographic Measures for Characterizing Myofascial Trigger Points Associated with Cervical Pain. Journal of Ultrasound in Medicine. 2011.
5. Fernández-de-las-Peñas C, Dommerholt J. Myofascial Trigger Points: Peripheral or Central Phenomenon? Current Rheumatology Reports. 2014.
6. Myburgh C, Larsen AH, Hartvigsen J. A Systematic, Critical Review of Manual Palpation for Identifying Myofascial Trigger Points. 2008.
7. Lew J, Kim J, Nair P. Comparison of Dry Needling and Trigger Point Manual Therapy in Patients with Neck and Upper Back Myofascial Pain Syndrome: A Systematic Review and Meta-analysis. 2021.