Trigger Points Explained: What’s Really Causing That Stubborn Knot in Your Shoulder

You’ve felt it before. That persistent knot in your shoulder that no amount of stretching or massage seems to fully resolve. It loosens temporarily, then returns within days. The discomfort might radiate into your neck or down your arm, making it difficult to pinpoint where the problem actually originates.

What you’re likely experiencing is a myofascial trigger point. Understanding what these trigger points actually are, why they form, and how they’re treated can help explain why some approaches work better than others.

What Is a Trigger Point?

A trigger point is a hyperirritable spot within a taut band of skeletal muscle. The term “knot” is commonly used because these areas often feel like small, dense lumps beneath the skin. But the physiology is more complex than simple muscle tightness.

Trigger points involve sustained contraction of muscle fibers, reduced local blood flow, and an accumulation of sensitizing substances that keep the area irritated. This creates a self-perpetuating cycle. The contracted fibers compress local capillaries, limiting oxygen delivery. Without adequate oxygen, the muscle cannot produce enough energy to release the contraction. Meanwhile, the accumulated chemicals continue to sensitize local nerve endings, producing pain even without external pressure.

Active vs. Latent Trigger Points

Not all trigger points behave the same way. We distinguish between active and latent trigger points based on their symptoms.

Active trigger points cause spontaneous pain, meaning discomfort is present even at rest. They also produce characteristic referred pain patterns when pressed. For example, a trigger point in the upper trapezius muscle commonly refers pain up the side of the neck and into the temple, which many patients mistake for tension headaches.

Latent trigger points are painful only when pressed. They may restrict range of motion and cause muscle weakness but don’t produce constant discomfort. These latent points can exist without causing problems until stress, overuse, or injury activates them. Many people walk around with latent trigger points they don’t know about until something tips them into becoming active.

Why Trigger Points Form

Several factors contribute to trigger point development, and NYC life provides plenty of them.

Sustained postures are a major culprit. Sitting at a desk with shoulders rounded forward places certain muscles under constant low-level contraction. Over time, this leads to localized fatigue and trigger point formation.

Acute overload is another common cause. Lifting something heavy, sudden movements, or unaccustomed exercise can strain muscle fibers and initiate the contraction cycle. Repetitive motions like typing, scrolling, and carrying bags on one shoulder create cumulative microtrauma with similar effects.

Psychological stress plays a significant role as well. When you’re stressed, you carry tension in your shoulders. That unconscious bracing, sustained over hours and days, creates the perfect conditions for trigger points to develop.

Other contributing factors include poor sleep, nutritional deficiencies (particularly vitamin D, B12, and iron), and underlying joint dysfunction that causes compensatory muscle guarding.

Why Stretching and Massage Often Fall Short

Stretching can provide temporary relief by increasing blood flow and lengthening muscle fibers. However, if the trigger point’s contracted nodule remains, the muscle often returns to its shortened state within hours or days. The underlying problem hasn’t changed.

Massage works similarly. It can reduce superficial tension and improve circulation, but may not reach the deepest layers of muscle where trigger points reside. Some trigger points require sustained, precise pressure to release, which can be difficult to maintain manually.

This is where needle-based therapies offer an advantage. Dry needling in NYC has become increasingly popular among practitioners treating musculoskeletal pain precisely because it can access tissues that manual therapy cannot.

How Dry Needling Addresses Trigger Points

Dry needling involves inserting thin, solid filament needles directly into trigger points. The term “dry” distinguishes it from injections that deliver medication. Nothing is injected; the needle itself is the therapeutic tool.

When a needle penetrates a trigger point, it often produces what’s called a local twitch response, a brief, involuntary contraction of the muscle fibers within the taut band. Research published in the American Journal of Physical Medicine & Rehabilitation found that eliciting this twitch response is associated with better outcomes, suggesting it helps “reset” the dysfunctional muscle fibers.

The mechanical disruption also increases local blood flow and helps disperse the accumulated sensitizing substances. A study in the Journal of Orthopaedic & Sports Physical Therapy found that dry needling produced immediate improvements in pain pressure threshold and range of motion in patients with upper trapezius trigger points.

The Connection to East Asian Medicine

While dry needling is often discussed in Western biomechanical terms, it shares significant overlap with traditional acupuncture therapy in NYC and elsewhere. Many classical acupuncture points correspond anatomically to common trigger point locations. The needling techniques, while sometimes described differently, use similar tools and insertion methods.

In New York State, dry needling is legally recognized as a form of acupuncture and can only be performed by licensed acupuncturists. This ensures practitioners have comprehensive training in anatomy, needle technique, and safety protocols.

East Asian medicine also brings a broader diagnostic framework. Rather than treating trigger points in isolation, we assess patterns of muscle tension, postural imbalance, and systemic factors like stress and sleep quality.

What to Expect from Treatment

At Grand Madison Acupuncture, during a session for dry needling therapy in NYC, our practitioner will palpate the affected muscles to locate trigger points, then insert needles into those specific areas. You may feel a deep ache or cramping sensation when the needle contacts a trigger point, followed by a twitch response. Most patients describe immediate relief of tension afterward, though some soreness in the area is normal for 24 to 48 hours.

Multiple sessions are typically needed for chronic trigger points, as the muscle often requires repeated input to maintain a relaxed state. Depending on your condition, we may also recommend stretching, postural modifications, or stress management strategies to prevent recurrence.